Clinical Bacteriology

Gram-Positive Cocci

1. Prevalence and antimicrobial susceptibility profile of Staphylococcus aureus isolated from pus and wound specimens in a tertiary teaching hospital, using routine culture and disc diffusion with resistance proportions assessed at final reporting: a laboratory-based cross-sectional study.
2. Association of methicillin resistance with multidrug resistance among Staphylococcus aureus isolates from clinical specimens, using cefoxitin disc diffusion and routine antimicrobial susceptibility testing with resistance patterns assessed after overnight incubation: an analytical cross-sectional study.
3. Prevalence of inducible clindamycin resistance among erythromycin-resistant Staphylococcus aureus clinical isolates, using disc approximation testing and methicillin susceptibility as comparator with phenotype frequencies assessed after overnight incubation: a laboratory-based cross-sectional study.
4. Association of biofilm formation with methicillin resistance among Staphylococcus aureus isolates from wound infections, using microtitre plate biofilm assay and cefoxitin disc diffusion with outcomes assessed after isolate characterization: an analytical cross-sectional study.
5. Comparative antimicrobial susceptibility profiles of Staphylococcus aureus isolates from community-onset and hospital-acquired infections, using routine disc diffusion with acquisition category determined at specimen collection and resistance proportions assessed at final reporting.
6. Association of methicillin-resistant Staphylococcus aureus bloodstream infection with in-hospital mortality, using methicillin-susceptible Staphylococcus aureus bacteraemia as comparator and discharge outcome assessed during the index admission: a retrospective analytical study.
7. Prevalence and clinical significance of coagulase-negative staphylococci isolated from blood cultures, using predefined contamination criteria and repeat culture findings with true bloodstream infection status determined during the index admission: a retrospective observational study.
8. Association of biofilm formation with clinically significant bloodstream infection among coagulase-negative staphylococci, using microtitre plate assay and contaminant isolates as comparator with classification completed during the same admission: an analytical cross-sectional study.
9. Species distribution and antimicrobial susceptibility of clinically significant Streptococcus isolates from respiratory, blood, and sterile body fluid specimens, using routine culture identification with resistance proportions assessed at final laboratory reporting: a cross-sectional study.
10. Diagnostic accuracy of optochin susceptibility and bile solubility for identification of Streptococcus pneumoniae from clinical isolates, using automated identification as reference with sensitivity and specificity assessed after final isolate characterization: a laboratory-based study.
11. Association of penicillin susceptibility with specimen source among Streptococcus pneumoniae isolates, using routine minimum inhibitory concentration testing and source categories recorded at culture positivity with resistance proportions assessed at final reporting: a cross-sectional study.
12. Species distribution and antimicrobial susceptibility of beta-haemolytic streptococci isolated from clinical specimens, using conventional identification and routine susceptibility testing with resistance patterns assessed at final reporting: a laboratory-based cross-sectional study.
13. Prevalence and antimicrobial susceptibility profile of Enterococcus faecalis and Enterococcus faecium from urine, blood, and wound specimens, using routine identification and susceptibility testing with resistance proportions assessed at final reporting.
14. Association of vancomycin resistance with multidrug resistance among Enterococcus faecalis and Enterococcus faecium isolates, using broth microdilution and routine susceptibility testing with resistance patterns assessed after isolate characterization: an analytical cross-sectional study.

Gram-Negative Bacilli

15. Prevalence and antimicrobial susceptibility profile of Escherichia coli causing urinary tract infection among adult patients, using quantitative urine culture and routine susceptibility testing with resistance proportions assessed at final reporting: a laboratory-based cross-sectional study.
16. Prevalence of extended spectrum beta lactamase production among Escherichia coli and Klebsiella pneumoniae clinical isolates, using combination-disc confirmatory testing with antimicrobial resistance profiles assessed after overnight incubation: a laboratory-based cross-sectional study.
17. Prevalence of AmpC beta lactamase production among cefoxitin-resistant Enterobacterales, using a routinely available phenotypic confirmatory method with species distribution and co-resistance patterns assessed after isolate characterization.
18. Prevalence of carbapenemase production among carbapenem-resistant Enterobacterales from clinical specimens, using modified carbapenem inactivation testing with organism distribution and antimicrobial susceptibility profiles assessed at final reporting.
19. Association of carbapenemase production with multidrug resistance among Klebsiella pneumoniae isolates, using phenotypic carbapenemase testing and routine susceptibility results with resistance burden assessed after isolate characterization: an analytical cross-sectional study.
20. Comparative antimicrobial susceptibility of community-onset and hospital-acquired Enterobacterales urinary isolates, using routine culture and disc diffusion with acquisition status determined at specimen collection and resistance proportions assessed at final reporting.
21. Association of prior hospitalisation with infection caused by multidrug-resistant Enterobacterales, using susceptible Enterobacterales infections as comparator and hospitalisation during the preceding ninety days assessed from case records: a case-control study.
22. Association of prior broad-spectrum antibiotic exposure with extended spectrum beta lactamase-producing Enterobacterales infection, using non-producing isolates as comparator and exposure during the preceding ninety days assessed from medical records.
23. Species distribution and antimicrobial susceptibility of Enterobacterales isolated from bloodstream infections among adults, using automated blood culture and routine susceptibility testing with organism-specific resistance proportions assessed during the index admission.
24. Association of carbapenem-resistant Klebsiella pneumoniae bloodstream infection with mortality, using carbapenem-susceptible Klebsiella pneumoniae bacteraemia as comparator and discharge outcome assessed during the same admission: a retrospective analytical study.
25. Prevalence and antimicrobial susceptibility profile of Pseudomonas aeruginosa from respiratory, wound, and urine specimens, using conventional or automated identification with resistance proportions assessed at final laboratory reporting: a cross-sectional study.
26. Association of carbapenem resistance with multidrug resistance among Pseudomonas aeruginosa clinical isolates, using meropenem susceptibility and routine antimicrobial testing with resistance categories assessed after overnight incubation: an analytical cross-sectional study.
27. Association of biofilm formation with carbapenem resistance among Pseudomonas aeruginosa isolates, using microtitre plate assay and routine susceptibility testing with biofilm category and resistance assessed after isolate characterization.
28. Comparative antimicrobial susceptibility profiles of Pseudomonas aeruginosa isolates from intensive care unit and general ward patients, using routine susceptibility testing with ward location recorded at specimen collection and resistance proportions assessed at final reporting.
29. Prevalence and antimicrobial susceptibility profile of Acinetobacter baumannii from intensive care unit clinical specimens, using routine identification and susceptibility testing with carbapenem resistance and multidrug resistance proportions assessed at final reporting.
30. Association of biofilm formation with carbapenem resistance among Acinetobacter baumannii isolates, using microtitre plate assay and meropenem susceptibility testing with outcomes assessed after isolate characterization: an analytical cross-sectional study.
31. Association of mechanical ventilation with acquisition of carbapenem-resistant Acinetobacter baumannii respiratory infection, using carbapenem-susceptible infections as comparator and ventilation exposure assessed before culture positivity: a case-control study.
32. Association of carbapenem-resistant Acinetobacter baumannii infection with in-hospital mortality, using carbapenem-susceptible Acinetobacter baumannii infection as comparator and outcome assessed at discharge: a retrospective analytical study.
33. Prevalence and antimicrobial susceptibility of Stenotrophomonas maltophilia isolated from clinical specimens, using routine identification and susceptibility testing with specimen distribution and resistance patterns assessed at final reporting.
34. Clinical significance of Stenotrophomonas maltophilia isolated from respiratory specimens, using predefined infection criteria and colonization as comparator with clinical classification completed during the index admission: a retrospective observational study.

Gram-Negative Cocci

35. Diagnostic yield and antimicrobial susceptibility of Neisseria gonorrhoeae from clinically indicated genital specimens, using routine culture and susceptibility testing with culture positivity and resistance patterns assessed at final reporting.
36. Agreement between Gram-stain microscopy and culture for presumptive detection of Neisseria gonorrhoeae in symptomatic male urethral specimens, using culture as reference with sensitivity and specificity assessed during the same diagnostic episode.
37. Prevalence and antimicrobial susceptibility of Moraxella catarrhalis isolated from respiratory specimens, using routine culture identification and susceptibility testing with resistance proportions assessed at final reporting: a laboratory-based cross-sectional study.
38. Association of Moraxella catarrhalis isolation with chronic respiratory disease among adult patients, using culture-negative respiratory specimens as comparator and clinical diagnosis assessed during the same hospital encounter.

Anaerobic Bacteria

39. Diagnostic yield of anaerobic culture in clinically selected deep wound and abscess specimens, using paired aerobic culture as comparator with additional pathogen recovery assessed at final culture reporting: a prospective laboratory-based study.
40. Association of specimen type with anaerobic bacterial recovery from deep-seated infections, using routine anaerobic culture and final organism identification with positivity proportions assessed after completion of incubation.
41. Comparative microbiological yield of tissue and swab specimens for anaerobic bacterial recovery in deep wound infections when both are clinically collected, with concordance assessed at final culture reporting.
42. Association of pre-analytical transport delay with anaerobic culture positivity, using promptly transported specimens as comparator and pathogen recovery assessed at completion of routine incubation: a prospective observational study.
43. Spectrum and antimicrobial susceptibility of clinically significant anaerobic bacteria isolated from surgical and deep soft-tissue infections, using routine identification with organism distribution assessed at final laboratory reporting.
44. Association of polymicrobial aerobic-anaerobic infection with adverse clinical outcome in deep soft-tissue infections, using monomicrobial infections as comparator and outcome assessed at discharge: a retrospective analytical study.

Spore-Forming Bacteria

45. Diagnostic yield of stool toxin testing for Clostridioides difficile among hospitalised adults with antibiotic-associated diarrhoea, using clinical case definition as comparator and positivity assessed during the diarrhoeal episode.
46. Association of prior broad-spectrum antibiotic exposure with Clostridioides difficile infection, using toxin-negative diarrhoeal patients as comparator and antimicrobial exposure during the preceding ninety days assessed from records.
47. Association of Clostridioides difficile toxin positivity with leukocytosis and renal dysfunction, using routine toxin testing and laboratory parameters measured within twenty-four hours of diagnosis: an analytical cross-sectional study.
48. Association of Clostridioides difficile infection with prolonged hospitalisation, using toxin-negative antibiotic-associated diarrhoea as comparator and length of stay measured until discharge: a retrospective observational study.
49. Clinical significance of Bacillus species isolated from blood cultures, using repeat culture and predefined contamination criteria with true bloodstream infection status determined during the index admission: a retrospective study.
50. Association of repeated Bacillus species blood culture positivity with central venous catheter exposure, using single positive cultures as comparator and device status assessed during the same admission.

Fastidious Bacteria

51. Diagnostic yield of chocolate agar culture for fastidious respiratory bacteria among acceptable-quality sputum specimens, using routine blood agar culture as comparator with incremental recovery assessed at forty-eight hours.
52. Association of Haemophilus influenzae isolation with chronic obstructive airway disease among adults with lower respiratory infection, using other bacterial respiratory infections as comparator and diagnosis assessed during admission.
53. Prevalence and antimicrobial susceptibility of Haemophilus influenzae isolated from respiratory specimens, using routine culture identification with beta-lactam susceptibility and resistance patterns assessed at final reporting.
54. Diagnostic yield of enriched culture for fastidious bacteria in sterile body fluids, using conventional culture as comparator with additional pathogen recovery assessed at final culture reporting.
55. Association of prior antibiotic exposure with culture negativity in clinically suspected fastidious bacterial infection, using antibiotic-unexposed patients as comparator and culture outcome assessed during the same episode.
56. Retrospective spectrum of fastidious bacterial isolates from blood and sterile body fluids in a teaching hospital, using laboratory records with annual organism distribution assessed over three years.

Atypical Bacteria

57. Seroprevalence of Mycoplasma pneumoniae antibodies among children and adults with community-acquired pneumonia where routine serology is available, with positivity and clinical characteristics assessed during the index illness.
58. Association of Mycoplasma pneumoniae seropositivity with radiological and haematological findings in community-acquired pneumonia, using seronegative pneumonia as comparator and parameters obtained during the same admission.
59. Diagnostic agreement between Mycoplasma pneumoniae serology and routinely available molecular testing in respiratory specimens, with concordance assessed during the same acute respiratory episode.
60. Prevalence of Chlamydia trachomatis infection among symptomatic women using a routinely available nucleic acid amplification assay, with age and clinical presentation assessed at the same visit: a cross-sectional study.
61. Association of Chlamydia trachomatis positivity with cervicitis among reproductive-age women, using nucleic acid amplification testing and clinically assessed cervicitis status during the same visit.
62. Diagnostic agreement between a rapid antigen method and nucleic acid amplification testing for Chlamydia trachomatis where both are routinely available, with concordance assessed on the same clinical specimen.
63. Seroprevalence of scrub typhus among acute undifferentiated febrile illness patients, using immunoglobulin M enzyme linked immunosorbent assay with seasonal distribution assessed over twelve months.
64. Association of scrub typhus immunoglobulin M positivity with thrombocytopenia and hepatic dysfunction, using routine serology and laboratory parameters measured during the index admission.
65. Association of scrub typhus seropositivity with intensive care unit admission, using seronegative acute febrile illness as comparator and clinical outcome assessed during hospitalisation.
66. Diagnostic performance of a rapid scrub typhus antibody test against immunoglobulin M enzyme linked immunosorbent assay, with sensitivity and specificity assessed during the same acute febrile episode.
67. Comparative clinical and laboratory profiles of scrub typhus and dengue among serologically confirmed patients, using routine diagnostic assays with complications and discharge outcomes assessed during the same admission.
68. Seasonal distribution of laboratory-confirmed scrub typhus among acute febrile illness patients, using routine serology records with monthly positivity proportions assessed over two years.
69. Association of delay from symptom onset to scrub typhus diagnosis with organ dysfunction, using serologically confirmed cases and complications documented during the index admission.
70. Seroprevalence of rickettsial infection among patients with acute undifferentiated fever, using routinely available serology with clinical and seasonal correlates assessed during the same episode.

Mycobacteriology

Mycobacterium tuberculosis

71. Diagnostic accuracy of Ziehl-Neelsen smear microscopy for pulmonary tuberculosis among symptomatic adults, using mycobacterial culture as reference with sensitivity and specificity assessed at final culture reporting: a prospective cross-sectional study.
72. Agreement between fluorescent microscopy and Ziehl-Neelsen staining for detection of acid-fast bacilli in sputum, using cartridge based nucleic acid amplification testing as reference with concordance assessed on the same specimen.
73. Association of sputum smear grade with semiquantitative cartridge based nucleic acid amplification test category in pulmonary tuberculosis, using paired results from the same specimen with correlation assessed at initial diagnosis.
74. Association of sputum smear grade with time to positivity in mycobacterial culture, using routinely processed pulmonary specimens and culture timing assessed at final laboratory reporting: a laboratory-based analytical study.
75. Diagnostic yield of cartridge based nucleic acid amplification testing among smear-negative patients with suspected pulmonary tuberculosis, using mycobacterial culture as comparator with additional detection assessed at final diagnosis.
76. Agreement between cartridge based nucleic acid amplification testing and mycobacterial culture for pulmonary tuberculosis, with discordant results characterized after final clinical and microbiological assessment.
77. Association of prior antitubercular treatment with smear and culture positivity among patients evaluated for pulmonary tuberculosis, using treatment-naive patients as comparator and microbiological results assessed during the diagnostic episode.
78. Association of cavitary lung disease with sputum bacillary burden among microbiologically confirmed pulmonary tuberculosis patients, using smear grade and molecular semiquantitative category assessed at diagnosis.
79. Association of diabetes mellitus with sputum bacillary burden in pulmonary tuberculosis, using non-diabetic patients as comparator and smear grade assessed at initial microbiological diagnosis.
80. Association of human immunodeficiency virus infection with smear negativity among culture-confirmed pulmonary tuberculosis, using human immunodeficiency virus-negative cases as comparator and microscopy results assessed at diagnosis.
81. Retrospective three-year trend of microbiologically confirmed pulmonary tuberculosis in a teaching hospital, using laboratory records with annual positivity and rifampicin resistance proportions compared by calendar year.
82. Association of sputum specimen quality with mycobacterial culture contamination and positivity, using routine collection characteristics and final culture outcome assessed after completion of incubation.
83. Diagnostic yield of a second sputum specimen after an initially negative smear in patients evaluated for pulmonary tuberculosis, using cumulative microbiological confirmation as reference and additional yield assessed within three days.
84. Agreement between morning and spot sputum specimens for acid-fast bacillus detection when both are clinically submitted, using cumulative microbiological diagnosis as reference and concordance assessed during the same evaluation.
85. Association of cartridge based nucleic acid amplification test bacterial load category with radiological extent of pulmonary tuberculosis, using chest imaging recorded at diagnosis and molecular results from the same episode.
86. Turnaround time comparison of smear microscopy, cartridge based nucleic acid amplification testing, and mycobacterial culture for pulmonary tuberculosis, measuring time from specimen receipt to verified laboratory result prospectively.
87. Association of pretreatment sputum bacillary burden with smear conversion at routine follow-up among pulmonary tuberculosis patients, using initial smear grade and programmatically obtained follow-up results within six months.
88. Frequency and causes of invalid or indeterminate cartridge based nucleic acid amplification test results in pulmonary specimens, using repeat testing as comparator with final valid-result status assessed within forty-eight hours.

Extrapulmonary Tuberculosis

89. Diagnostic accuracy of cartridge based nucleic acid amplification testing for extrapulmonary tuberculosis, using mycobacterial culture as reference with sensitivity and specificity assessed separately by specimen type at final reporting.
90. Diagnostic yield of cartridge based nucleic acid amplification testing in lymph node specimens from suspected tuberculous lymphadenitis, using culture or composite diagnosis as reference and yield assessed during the diagnostic episode.
91. Diagnostic accuracy of cartridge based nucleic acid amplification testing in pleural fluid for suspected pleural tuberculosis, using mycobacterial culture and clinical diagnosis as reference with performance assessed at final diagnosis.
92. Diagnostic accuracy of cartridge based nucleic acid amplification testing in cerebrospinal fluid for tuberculous meningitis, using composite clinical and microbiological diagnosis as reference and performance assessed during admission.
93. Diagnostic yield of mycobacterial culture from pus, tissue, lymph node, pleural fluid, and cerebrospinal fluid specimens, with positivity proportions compared by specimen type at final culture reporting.
94. Association of specimen volume with microbiological yield in suspected extrapulmonary tuberculosis, using routinely submitted specimens and positivity by smear, molecular testing, or culture assessed at final diagnosis.
95. Agreement between smear microscopy and cartridge based nucleic acid amplification testing in extrapulmonary specimens, using culture as reference with concordance assessed after final laboratory reporting.
96. Association of human immunodeficiency virus infection with microbiological yield in extrapulmonary tuberculosis, using human immunodeficiency virus-negative patients as comparator and confirmation assessed during the index evaluation.
97. Comparative diagnostic yield of fine-needle aspirate and tissue specimens for tuberculous lymphadenitis when both are clinically obtained, using composite microbiological diagnosis as reference and concordance assessed during the same episode.
98. Retrospective distribution of extrapulmonary tuberculosis by specimen type and anatomical site, using microbiology laboratory records with annual positivity proportions assessed over three years.
99. Association of prior antitubercular treatment with microbiological positivity in suspected extrapulmonary tuberculosis, using treatment-naive patients as comparator and laboratory confirmation assessed at final diagnosis.
100. Turnaround time comparison of molecular testing and mycobacterial culture in extrapulmonary tuberculosis, measuring time from specimen receipt to actionable verified result prospectively.

Drug-Resistant Tuberculosis

101. Prevalence of rifampicin-resistant Mycobacterium tuberculosis among cartridge based nucleic acid amplification test-positive pulmonary specimens, with patient treatment history and resistance proportions assessed at initial diagnosis: a cross-sectional study.
102. Agreement between cartridge based nucleic acid amplification testing and line probe assay for rifampicin resistance among Mycobacterium tuberculosis-positive specimens, with discordance assessed after completion of both methods.
103. Agreement between line probe assay and routine phenotypic susceptibility testing for isoniazid and rifampicin resistance among Mycobacterium tuberculosis isolates, with concordance assessed at final characterization.
104. Prevalence of multidrug-resistant tuberculosis among previously treated and treatment-naive patients, using routine molecular or phenotypic susceptibility testing with resistance status assessed during the initial diagnostic episode.
105. Association of prior tuberculosis treatment with multidrug-resistant tuberculosis, using drug-susceptible tuberculosis as comparator and treatment history obtained at diagnosis: a hospital-based analytical cross-sectional study.
106. Association of treatment interruption history with multidrug-resistant tuberculosis, using drug-susceptible tuberculosis as comparator and previous treatment records reviewed at the time of diagnosis.
107. Prevalence of fluoroquinolone resistance among rifampicin-resistant Mycobacterium tuberculosis detected by line probe assay, with resistance patterns assessed at completion of routine second-line testing.
108. Distribution of multidrug-resistant, pre-extensively drug-resistant, and extensively drug-resistant tuberculosis among routinely tested resistant isolates, using line probe assay or phenotypic susceptibility with categories assessed at final reporting.
109. Association of diabetes mellitus with drug-resistant pulmonary tuberculosis, using drug-susceptible tuberculosis as comparator and diabetic status documented during the same admission or clinic episode.
110. Association of human immunodeficiency virus infection with drug-resistant tuberculosis, using drug-susceptible tuberculosis as comparator and resistance category established during initial microbiological evaluation.
111. Diagnostic agreement between molecular rifampicin resistance detection and phenotypic susceptibility testing, with discordant Mycobacterium tuberculosis isolates retested and final resistance status assigned after laboratory verification.
112. Retrospective three-year trend of rifampicin-resistant and multidrug-resistant tuberculosis, using routine laboratory resistance records with annual proportions compared by calendar year.

Non-Tuberculous Mycobacteria

113. Prevalence and species distribution of non-tuberculous mycobacteria among mycobacterial culture-positive respiratory specimens, using routine identification methods with clinical significance assessed by accepted criteria during the diagnostic episode.
114. Association of repeated isolation of non-tuberculous mycobacteria with chronic structural lung disease, using single-isolation patients as comparator and clinical diagnoses obtained from case records.
115. Clinical significance of non-tuberculous mycobacteria isolated from respiratory specimens, using accepted microbiological criteria and final clinician diagnosis with disease versus colonization classified within three months.
116. Comparative clinical characteristics of pulmonary tuberculosis and non-tuberculous mycobacterial pulmonary disease, using culture-confirmed cases with laboratory and radiological parameters assessed at diagnosis.
117. Distribution of non-tuberculous mycobacterial isolates across pulmonary and extrapulmonary specimens, using routine culture and identification with specimen-specific frequencies assessed at final laboratory reporting.
118. Retrospective surveillance of non-tuberculous mycobacterial isolation in a teaching hospital, using laboratory culture records with annual species distribution and specimen sources assessed over three years.

Diagnostic Methods

119. Inter-observer agreement in acid-fast bacillus smear grading by Ziehl-Neelsen microscopy, using senior microbiologist consensus as reference with kappa and grading discrepancies assessed on routinely prepared sputum smears.
120. Comparative sensitivity of Ziehl-Neelsen and fluorescent microscopy for pulmonary tuberculosis, using culture-positive sputum specimens as reference with detection rates compared on the same specimen.
121. Association of sputum processing delay with smear and culture positivity for Mycobacterium tuberculosis, using promptly processed specimens as comparator and final microbiological outcomes assessed prospectively.
122. Frequency and determinants of mycobacterial culture contamination in pulmonary specimens, using routine culture records with specimen quality and processing factors assessed at final culture reporting.
123. Diagnostic yield of mycobacterial culture among molecular-test-negative patients with suspected tuberculosis, using final clinical diagnosis as comparator and additional microbiological confirmation assessed after incubation.
124. Agreement between cartridge based nucleic acid amplification testing and Truenat molecular testing for Mycobacterium tuberculosis where both are routinely available, with concordance assessed on the same specimen.
125. Agreement between cartridge based nucleic acid amplification testing and Truenat testing for rifampicin resistance, using line probe assay as reference where performed and discordance assessed after characterization.
126. Diagnostic accuracy of Truenat testing for pulmonary tuberculosis, using mycobacterial culture as reference with sensitivity and specificity assessed at final culture reporting.
127. Diagnostic accuracy of Truenat testing for extrapulmonary tuberculosis, using mycobacterial culture or composite diagnosis as reference with specimen-specific performance assessed at final diagnosis.
128. Agreement between line probe assay and conventional susceptibility testing for first-line drug resistance in Mycobacterium tuberculosis, with concordance assessed after completion of both methods.
129. Frequency of invalid and indeterminate line probe assay results, using repeat testing as comparator with final interpretable-result rate assessed over twelve months.
130. Diagnostic yield of line probe assay directly from smear-positive sputum compared with testing from cultured isolates, with concordance and turnaround time assessed prospectively.
131. Comparative turnaround time of smear microscopy, Truenat testing, cartridge based nucleic acid amplification testing, line probe assay, and culture in routinely investigated tuberculosis specimens.
132. Association of cartridge based nucleic acid amplification test semiquantitative category with culture time to positivity, using paired positive pulmonary specimens with correlation assessed at final culture reporting.
133. Diagnostic performance of smear microscopy in human immunodeficiency virus-associated pulmonary tuberculosis, using molecular or culture confirmation as reference and sensitivity assessed at final diagnosis.
134. Diagnostic performance of molecular testing in smear-negative extrapulmonary tuberculosis, using culture or composite diagnosis as reference and sensitivity assessed during the index evaluation.
135. Agreement between duplicate molecular testing of low-positive tuberculosis specimens, using repeat testing from the same residual specimen with reproducibility assessed within forty-eight hours.
136. Audit of tuberculosis specimen rejection and pre-analytical errors, using laboratory acceptance criteria with rejection frequency and causes assessed over twelve months.
137. Audit of tuberculosis laboratory turnaround times for smear microscopy, molecular testing, line probe assay, and culture, using predefined departmental benchmarks with compliance assessed over six months.
138. Frequency and resolution of discordant smear, molecular, and culture results in tuberculosis diagnosis, using clinical records and repeat testing with final classification assessed within three months.
139. Diagnostic yield of repeat molecular testing after an initial invalid tuberculosis result, using subsequent valid testing as comparator and successful resolution assessed within forty-eight hours.
140. Retrospective evaluation of routine tuberculosis diagnostic algorithms in a teaching hospital, using laboratory records with stepwise test yield and time to microbiological confirmation assessed over twelve months.

Virology

Respiratory Viruses

141. Prevalence and seasonal distribution of influenza virus infection among patients with acute respiratory illness, using routine molecular testing with monthly positivity proportions assessed over twelve months: a laboratory-based cross-sectional study.
142. Association of influenza virus positivity with hospitalisation and intensive care unit admission, using influenza-negative respiratory illness as comparator and clinical outcomes assessed during the index episode.
143. Prevalence of respiratory syncytial virus infection among children hospitalised with acute lower respiratory illness, using routine antigen or molecular testing with age-specific positivity assessed during admission.
144. Association of respiratory syncytial virus positivity with oxygen requirement among hospitalised children, using virus-negative lower respiratory illness as comparator and respiratory support assessed during the same admission.
145. Prevalence and clinical profile of severe acute respiratory syndrome coronavirus 2 infection among symptomatic hospital attendees, using routine molecular or antigen testing with outcomes assessed during the acute episode.
146. Agreement between rapid antigen testing and molecular testing for severe acute respiratory syndrome coronavirus 2 in symptomatic patients, with sensitivity and specificity assessed on specimens collected during the same visit.
147. Prevalence of adenovirus among children with acute respiratory infection, using routinely available molecular or antigen testing with clinical characteristics assessed during the index illness.
148. Prevalence of parainfluenza virus among hospitalised children with lower respiratory tract infection, using routine molecular testing with seasonal distribution assessed over twelve months.
149. Diagnostic yield of a multiplex respiratory viral panel compared with conventional targeted tests, using hospitalised patients with acute respiratory illness and additional detections assessed during the same episode.
150. Comparative clinical profiles of influenza virus, respiratory syncytial virus, and severe acute respiratory syndrome coronavirus 2 infections, using laboratory-confirmed cases with discharge outcomes assessed during admission.

Hepatitis Viruses

151. Seroprevalence of hepatitis A virus immunoglobulin M among patients with acute hepatitis, using routine serology with age distribution and liver enzyme abnormalities assessed during the index episode.
152. Seroprevalence of hepatitis B surface antigen among hospital attendees, using routine immunoassay with demographic and clinical characteristics assessed at the same encounter: a cross-sectional study.
153. Association of hepatitis B surface antigen positivity with elevated liver enzymes among hospital patients, using antigen-negative patients as comparator and biochemical parameters measured during the same episode.
154. Agreement between rapid hepatitis B surface antigen testing and chemiluminescent immunoassay, using the laboratory immunoassay as reference with sensitivity and specificity assessed on the same serum sample.
155. Seroprevalence of hepatitis C virus antibodies among haemodialysis patients, using routine immunoassay with dialysis duration and transfusion history assessed at enrollment.
156. Association of hepatitis C virus antibody positivity with prior blood transfusion among haemodialysis patients, using antibody-negative patients as comparator and exposure assessed from records.
157. Agreement between hepatitis C virus antibody screening and routinely available molecular confirmation, with positive predictive value assessed among reactive serum samples during the same diagnostic episode.
158. Prevalence of hepatitis D virus serological markers among hepatitis B surface antigen-positive patients where testing is routinely available, with liver disease severity assessed during the same evaluation.
159. Seroprevalence of hepatitis E virus immunoglobulin M among patients with acute hepatitis, using routine serology with seasonal distribution and liver dysfunction assessed during the index illness.
160. Comparative clinical and biochemical profiles of hepatitis A virus and hepatitis E virus infection, using serologically confirmed cases with liver function and discharge outcomes assessed during the same admission.

Herpesviruses

161. Seroprevalence of herpes simplex virus type-specific antibodies among pregnant women where routinely tested, using routine immunoassay with obstetric history assessed at the same antenatal visit.
162. Diagnostic yield of molecular testing for herpes simplex virus in cerebrospinal fluid from suspected encephalitis, using final clinical diagnosis as comparator with positivity assessed during the index admission.
163. Diagnostic yield of molecular testing for varicella zoster virus in cerebrospinal fluid from suspected neurological infection, using clinical diagnosis as comparator with results assessed during admission.
164. Association of cytomegalovirus viral load positivity with immunosuppression category among transplant and oncology patients, using routine molecular testing with clinical status assessed during the same episode.
165. Association of cytomegalovirus viral load with symptomatic disease among transplant recipients, using asymptomatic viral detection as comparator and clinical manifestations assessed within thirty days.
166. Association of Epstein-Barr virus serological pattern with acute infectious mononucleosis among symptomatic patients, using routine antibody testing and clinical criteria assessed during the same episode.
167. Diagnostic agreement between serology and molecular testing for selected herpesvirus infections where both are routinely performed, with concordance assessed on specimens from the same clinical episode.

Arboviruses

168. Diagnostic accuracy of dengue non-structural protein one antigen testing in acute febrile illness, using enzyme linked immunosorbent assay or molecular testing as reference with performance assessed by day of illness.
169. Association of dengue non-structural protein one antigen positivity with thrombocytopenia, using laboratory-confirmed dengue cases and platelet counts measured during the same acute episode.
170. Association of dengue immunoglobulin M positivity with day of illness, using routine enzyme linked immunosorbent assay and symptom onset recorded at specimen collection.
171. Seasonal distribution of laboratory-confirmed dengue infection in a tertiary teaching hospital, using routine antigen and antibody testing records with monthly positivity proportions assessed over two years.
172. Association of laboratory-confirmed dengue with intensive care unit admission, using dengue-negative acute febrile illness as comparator and clinical outcome assessed during hospitalisation.
173. Seroprevalence of chikungunya virus immunoglobulin M among acute febrile illness patients, using routine serology with seasonal distribution assessed over twelve months.
174. Comparative clinical and haematological profiles of dengue and chikungunya among laboratory-confirmed patients, using routine serology with complications assessed during the index admission.
175. Seroprevalence of Japanese encephalitis virus immunoglobulin M among patients with acute encephalitis syndrome where routine testing is available, with demographic and clinical outcomes assessed during admission.
176. Diagnostic yield of routine arboviral testing among acute encephalitis syndrome patients, using final clinical diagnosis as comparator with virus-specific positivity assessed during hospitalisation.
177. Retrospective laboratory surveillance of dengue, chikungunya, Japanese encephalitis, and other routinely tested arboviruses, with annual positivity and seasonal patterns assessed over three years.

Enteric Viruses

178. Prevalence of rotavirus antigen among children hospitalised with acute gastroenteritis, using routine stool antigen testing with age and dehydration severity assessed during admission.
179. Association of rotavirus positivity with severe dehydration among children with acute gastroenteritis, using rotavirus-negative cases as comparator and severity assessed at presentation.
180. Prevalence of norovirus among hospitalised gastroenteritis patients where routine molecular testing is available, with age distribution and seasonal positivity assessed over twelve months.
181. Prevalence of enteric adenovirus among children with acute gastroenteritis, using routine antigen or molecular testing with clinical severity assessed during the same admission.
182. Comparative clinical profiles of rotavirus, norovirus, and enteric adenovirus gastroenteritis among laboratory-confirmed children, with duration of hospitalisation and dehydration assessed during the index episode.

Retroviruses

183. Diagnostic agreement between routinely used human immunodeficiency virus screening assays and the national testing algorithm, with concordance and indeterminate-result frequency assessed during the same testing episode.
184. Seroprevalence of human immunodeficiency virus infection among patients tested in a tertiary teaching hospital, using the national testing algorithm with demographic distribution assessed over twelve months.
185. Association of CD4-positive T-lymphocyte count with opportunistic infection spectrum among adults with human immunodeficiency virus infection, using routine microbiological diagnoses from the same admission.
186. Association of human immunodeficiency virus viral load with CD4-positive T-lymphocyte count, using routinely monitored patients with paired measurements obtained within thirty days.
187. Association of virological nonsuppression with tuberculosis coinfection among adults receiving antiretroviral therapy, using virologically suppressed patients as comparator and tuberculosis status assessed within six months.
188. Retrospective trend of newly diagnosed human immunodeficiency virus infection and major opportunistic infections, using laboratory and clinic records with annual proportions assessed over three years.

Human Papillomavirus

189. Prevalence of high-risk human papillomavirus infection among women undergoing cervical screening where molecular testing is routinely available, with cytology findings assessed during the same screening episode.
190. Agreement between high-risk human papillomavirus molecular testing and cervical cytology for detection of significant cervical abnormalities, using histopathology where clinically performed as reference.
191. Association of high-risk human papillomavirus positivity with abnormal cervical cytology, using virus-negative screened women as comparator and cytological category assessed during the same visit.

Emerging and Re-Emerging Viruses

192. Retrospective laboratory surveillance of emerging and re-emerging viral infections tested in a tertiary hospital, using routine diagnostic records with annual positivity and seasonal patterns assessed over three years.
193. Diagnostic yield of multiplex molecular testing in patients with severe undifferentiated viral syndrome, using routine conventional virology as comparator with additional detections assessed during the index admission.
194. Association of travel or exposure history with laboratory-confirmed emerging viral infection, using test-negative suspected cases as comparator and exposures documented at presentation.
195. Audit of specimen referral and turnaround time for suspected emerging viral infections requiring reference laboratory testing, using laboratory timestamps with delays assessed over twelve months.

Mycology

Superficial Mycoses

196. Diagnostic accuracy of potassium hydroxide mount for superficial fungal infection, using fungal culture as reference with sensitivity and specificity assessed at final culture reporting: a prospective laboratory-based study.
197. Spectrum of superficial fungal infections diagnosed by microscopy and culture among dermatology patients, with anatomical site and organism distribution assessed at final laboratory reporting.
198. Association of prior topical antifungal use with culture negativity in suspected superficial mycosis, using untreated patients as comparator and exposure assessed at specimen collection.

Cutaneous Mycoses

199. Agreement between potassium hydroxide microscopy and fungal culture in suspected cutaneous mycosis, using culture as reference with concordance assessed at final laboratory reporting.
200. Association of diabetes mellitus with culture-confirmed cutaneous fungal infection, using culture-negative suspected cases as comparator and diabetic status assessed at the same clinical episode.
201. Comparative culture yield from skin scrapings, nail clippings, and hair specimens in suspected cutaneous mycosis, with specimen-specific positivity assessed at final fungal culture reporting.
202. Association of prior antifungal therapy with microscopy-culture discordance in cutaneous mycoses, using treatment-naive patients as comparator and laboratory results assessed during the same episode.
203. Seasonal distribution of culture-confirmed cutaneous mycoses, using routine mycology records with monthly positivity proportions assessed over twelve months.

Subcutaneous Mycoses

204. Spectrum of subcutaneous fungal infections diagnosed in a tertiary teaching hospital, using microscopy, culture, and histopathology where clinically available with organism distribution assessed at final diagnosis.
205. Diagnostic yield of fungal culture in clinically suspected subcutaneous mycosis, using histopathology or composite diagnosis as comparator with positivity assessed after completion of incubation.
206. Association of occupational soil exposure with culture-confirmed subcutaneous mycosis, using culture-negative suspected cases as comparator and exposure history recorded at presentation.

Systemic Mycoses

207. Spectrum of systemic fungal infections diagnosed by routine microbiology in immunocompromised patients, using culture, antigen, or molecular methods with organism distribution assessed during the index admission.
208. Diagnostic yield of fungal blood culture among patients with suspected systemic mycosis, using composite clinical diagnosis as comparator with positivity assessed at final culture reporting.
209. Association of systemic fungal infection with in-hospital mortality among immunocompromised patients, using patients without microbiological evidence of fungal infection as comparator and outcome assessed at discharge.

Opportunistic Mycoses

210. Prevalence and spectrum of opportunistic fungal infections among patients with human immunodeficiency virus infection, using routine mycology and antigen testing with CD4-positive T-lymphocyte counts assessed within thirty days.
211. Spectrum of opportunistic fungal infections among oncology patients, using routine culture and antigen testing with neutrophil counts and clinical outcomes assessed during the index admission.
212. Association of prolonged corticosteroid exposure with opportunistic fungal infection, using fungal-test-negative immunocompromised patients as comparator and steroid exposure assessed during the preceding ninety days.
213. Association of neutropenia with invasive fungal infection among haematological malignancy patients, using non-neutropenic patients as comparator and infection status assessed during the same admission.
214. Diagnostic yield of serum fungal biomarkers where routinely available in immunocompromised patients, using culture or composite diagnosis as reference with performance assessed during hospitalisation.
215. Retrospective distribution of opportunistic fungal infections in a teaching hospital, using laboratory records with annual organism frequency and patient risk groups assessed over three years.
216. Association of opportunistic fungal infection with intensive care unit admission among immunocompromised patients, using fungal-test-negative patients as comparator and outcome assessed during hospitalisation.
217. Association of prior broad-spectrum antibiotic exposure with invasive candidiasis among hospitalised adults, using culture-negative high-risk patients as comparator and exposure assessed during the preceding ninety days.

Candida

218. Species distribution and antifungal susceptibility of Candida bloodstream isolates, using routine culture identification and susceptibility testing with resistance proportions assessed during the index admission: a laboratory-based cross-sectional study.
219. Association of non-albicans Candida bloodstream infection with prior antifungal exposure, using Candida albicans bloodstream infection as comparator and exposure assessed during the preceding ninety days.
220. Association of candidemia with central venous catheter exposure, using matched blood culture-negative high-risk patients as comparator and device exposure assessed before culture positivity.
221. Association of candidemia with in-hospital mortality, using comparable high-risk patients without candidemia as comparator and outcome assessed at discharge: a retrospective analytical study.
222. Association of Candida species with intensive care unit acquisition, using general-ward candidemia as comparator and ward location determined at first positive blood culture.
223. Prevalence and species distribution of candiduria among catheterized inpatients, using quantitative urine culture with clinical significance assessed during the same admission.
224. Association of urinary catheterisation with candiduria, using culture-negative inpatients as comparator and catheter exposure assessed at specimen collection: a hospital-based case-control study.

Aspergillus

225. Diagnostic yield of respiratory fungal culture for Aspergillus species among high-risk patients, using composite clinical diagnosis as comparator with positivity assessed during the index admission.
226. Association of Aspergillus culture positivity with underlying chronic lung disease, using culture-negative suspected fungal respiratory infection as comparator and clinical diagnosis recorded during hospitalisation.
227. Diagnostic performance of serum or respiratory galactomannan where routinely available for suspected invasive aspergillosis, using composite clinical diagnosis as reference with sensitivity assessed during admission.
228. Association of neutropenia with probable or proven invasive aspergillosis among oncology patients, using non-neutropenic high-risk patients as comparator and fungal diagnosis established during admission.
229. Species distribution and antifungal susceptibility of Aspergillus isolates from clinically significant specimens, using routine identification and susceptibility testing with resistance patterns assessed at final reporting.

Cryptococcus

230. Diagnostic accuracy of cryptococcal antigen lateral-flow testing in cerebrospinal fluid, using fungal culture or composite diagnosis as reference with sensitivity and specificity assessed during the index admission.
231. Agreement between India ink microscopy and cryptococcal antigen testing in cerebrospinal fluid, using culture as reference where available with concordance assessed during the same diagnostic episode.
232. Association of serum cryptococcal antigen positivity with low CD4-positive T-lymphocyte count among adults with human immunodeficiency virus infection, using antigen-negative patients as comparator.
233. Association of cryptococcal meningitis with in-hospital mortality among adults with human immunodeficiency virus infection, using other central nervous system opportunistic infections as comparator and outcome assessed at discharge.

Mucormycosis

234. Association of uncontrolled diabetes mellitus with microbiologically confirmed mucormycosis, using patients with other invasive mould infections as comparator and glycaemic parameters assessed at diagnosis.
235. Association of diabetic ketoacidosis with rhino-orbital-cerebral mucormycosis, using mucormycosis without ketoacidosis as comparator and metabolic status assessed at presentation.
236. Diagnostic yield of potassium hydroxide microscopy and fungal culture in suspected mucormycosis, using histopathology where clinically available as reference with performance assessed during admission.
237. Spectrum of Mucorales isolated from clinically suspected mucormycosis, using routine microscopy and culture with anatomical site and clinical outcome assessed during hospitalisation.

Dermatophytes

238. Species distribution of dermatophytes in skin, hair, and nail specimens from patients with suspected dermatophytosis, using fungal culture with site-specific frequencies assessed at final reporting.
239. Agreement between potassium hydroxide mount and culture for dermatophyte detection, using culture as reference with sensitivity and specificity assessed after completion of incubation.
240. Association of recurrent dermatophytosis with prior topical corticosteroid use, using first-episode culture-confirmed dermatophytosis as comparator and exposure assessed during the preceding six months.
241. Association of dermatophyte species with anatomical site of infection, using culture-confirmed isolates and clinical site documented at specimen collection.
242. Association of prior antifungal therapy with dermatophyte culture negativity, using treatment-naive suspected cases as comparator and exposure assessed at specimen collection.

Antifungal Susceptibility

243. Antifungal susceptibility profile of Candida bloodstream isolates, using broth microdilution or validated automated susceptibility testing with species-specific resistance proportions assessed at final reporting.
244. Agreement between gradient diffusion and broth microdilution for fluconazole susceptibility among Candida isolates, using current interpretive criteria with essential and categorical agreement assessed after testing.

Antifungal Resistance

245. Prevalence of fluconazole resistance among non-albicans Candida clinical isolates, using routine antifungal susceptibility testing with species-specific resistance proportions assessed at final reporting: a laboratory-based cross-sectional study.

Parasitology

Intestinal Protozoa

246. Prevalence of intestinal protozoal infection among patients submitting stool specimens for gastrointestinal symptoms, using direct wet mount and concentration methods with parasite distribution assessed at final reporting.
247. Agreement between direct wet mount and concentration methods for detection of Entamoeba histolytica-dispar complex, using combined microscopy as reference with concordance assessed on the same stool specimen.
248. Diagnostic yield of stool antigen testing for Entamoeba histolytica where routinely available, using microscopy as comparator with additional detection assessed during the same diarrhoeal episode.
249. Prevalence of Giardia duodenalis infection among children with diarrhoea, using microscopy or antigen detection with age and symptom duration assessed during the same episode.
250. Diagnostic accuracy of stool antigen testing for Giardia duodenalis, using concentration microscopy as reference with sensitivity and specificity assessed on the same specimen.
251. Prevalence of Cryptosporidium infection among children with persistent diarrhoea, using modified acid-fast staining with human immunodeficiency virus status and nutritional status assessed at presentation.
252. Prevalence of Cryptosporidium infection among adults with human immunodeficiency virus infection and diarrhoea, using modified acid-fast staining with CD4-positive T-lymphocyte count assessed within thirty days.
253. Comparative yield of direct microscopy and concentration techniques for intestinal protozoa, using cumulative detection as reference with incremental diagnostic yield assessed on the same stool sample.

Blood Protozoa

254. Diagnostic accuracy of malaria rapid antigen testing among febrile patients, using peripheral blood smear microscopy as reference with sensitivity and species concordance assessed during the acute episode.
255. Agreement between thick and thin peripheral blood smears for malaria detection and species identification, using expert microscopy as reference with concordance assessed on the same blood sample.
256. Association of malaria parasite density with thrombocytopenia, using microscopy-confirmed malaria and platelet counts obtained during the same acute febrile episode.
257. Comparative haematological profiles of Plasmodium vivax and Plasmodium falciparum infection, using microscopy-confirmed cases with blood counts assessed at presentation.
258. Seasonal distribution of laboratory-confirmed malaria in a tertiary teaching hospital, using microscopy and rapid antigen records with monthly species-specific positivity assessed over two years.
259. Association of Plasmodium falciparum infection with severe malaria criteria, using Plasmodium vivax infection as comparator and complications assessed during admission.
260. Diagnostic yield of repeat malaria microscopy after an initially negative smear in clinically suspected cases, using cumulative detection as reference with additional yield assessed within forty-eight hours.
261. Retrospective identification of Babesia-like parasitemia among selected high-risk blood smear records where clinically suspected, using expert smear review and available confirmatory testing with final classification assessed after review.

Tissue Protozoa

262. Seroprevalence of Toxoplasma gondii immunoglobulin G among pregnant women, using routine immunoassay with age and obstetric history assessed at the same antenatal visit.
263. Prevalence of Toxoplasma gondii immunoglobulin M reactivity among pregnant women tested for suspected recent infection, using repeat or avidity testing where routinely available with final serological classification assessed within thirty days.
264. Association of Toxoplasma gondii seropositivity with adverse obstetric history, using seronegative pregnant women as comparator and previous pregnancy outcomes recorded at enrollment.
265. Seroprevalence of Toxoplasma gondii infection among adults with human immunodeficiency virus infection, using routine antibody testing with CD4-positive T-lymphocyte count assessed within thirty days.
266. Diagnostic yield of routine tests for visceral leishmaniasis among clinically suspected patients in endemic referrals, using composite clinical diagnosis as comparator with positivity assessed during admission.
267. Association of laboratory-confirmed visceral leishmaniasis with pancytopenia, using test-negative suspected cases as comparator and haematological parameters measured during the same diagnostic episode.

Intestinal Helminths

268. Prevalence of intestinal helminth infection among stool specimens submitted for gastrointestinal symptoms, using direct and concentration microscopy with species distribution assessed at final reporting.
269. Diagnostic yield of concentration methods over direct wet mount for Ascaris lumbricoides detection, using cumulative microscopy as reference with incremental yield assessed on the same stool specimen.
270. Prevalence of hookworm infection among patients undergoing stool microscopy, using concentration methods with anaemia status assessed from haemoglobin measured during the same clinical episode.
271. Association of hookworm infection with anaemia severity, using parasite-negative patients as comparator and haemoglobin levels obtained within seven days of stool testing.
272. Prevalence of Strongyloides stercoralis infection among immunocompromised patients with gastrointestinal symptoms, using routinely available concentration methods with immunosuppressive exposures assessed at testing.
273. Association of corticosteroid exposure with Strongyloides stercoralis infection, using parasite-negative immunocompromised patients as comparator and exposure during the preceding ninety days assessed from records.
274. Prevalence of Taenia species eggs among stool specimens submitted for parasitological examination, using concentration microscopy with age and clinical presentation assessed at the same episode.
275. Comparative yield of single and repeated stool examination for intestinal helminths, using cumulative detection as reference with additional diagnostic yield assessed within three days.

Tissue Helminths

276. Prevalence of circulating filarial antigen among clinically suspected patients where antigen testing is routinely available, using peripheral blood microscopy as comparator with concordance assessed during the same episode.
277. Agreement between nocturnal peripheral blood microscopy and circulating filarial antigen testing for lymphatic filariasis, using combined diagnosis as reference with concordance assessed within twenty-four hours.
278. Association of eosinophilia with laboratory-confirmed tissue helminth infection, using parasite-negative suspected patients as comparator and eosinophil counts obtained within seven days.
279. Serological profile of suspected cystic echinococcosis where routine antibody testing is available, using imaging diagnosis as comparator with concordance assessed during the same diagnostic evaluation.

Laboratory Diagnosis of Parasitic Infections

280. Inter-observer agreement in stool microscopy for intestinal parasites, using senior microscopist consensus as reference with kappa assessed on routinely prepared wet mounts and concentration preparations.
281. Diagnostic yield of formalin-ethyl acetate concentration over direct wet mount for intestinal parasites, using cumulative microscopy as reference with incremental detection assessed on the same specimen.
282. Inter-observer agreement in malaria species identification on peripheral blood smears, using expert consensus as reference with kappa assessed on routinely prepared smears.
283. Inter-observer agreement in malaria parasite density estimation, using expert parasite counts as reference with reproducibility assessed on the same smear set.
284. Diagnostic performance of rapid malaria antigen testing in low-parasitemia infections, using expert microscopy as reference with sensitivity assessed during the same acute febrile episode.
285. Audit of stool specimen quality and rejection in parasitology, using predefined laboratory criteria with rejection frequency and diagnostic impact assessed over six months.

Hospital-Acquired Infections

Catheter-Associated Urinary Tract Infection

286. Incidence density and microbiological profile of catheter-associated urinary tract infection among adult intensive care unit patients, using standardized surveillance definitions with infections and device-days recorded prospectively over twelve months.
287. Species distribution and antimicrobial susceptibility of uropathogens causing catheter-associated urinary tract infection, using quantitative urine culture with resistance proportions assessed at final laboratory reporting: a prospective surveillance study.
288. Association of urinary catheter duration with catheter-associated urinary tract infection, using catheterized patients without infection as comparator and device-days assessed until infection or catheter removal.
289. Association of diabetes mellitus with catheter-associated urinary tract infection among catheterized inpatients, using catheterized non-infected patients as comparator and diabetic status documented during admission.
290. Association of prior broad-spectrum antibiotic exposure with multidrug-resistant catheter-associated urinary tract infection, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
291. Association of biofilm formation with catheter-associated urinary tract infection among Escherichia coli and Klebsiella pneumoniae, using microtitre plate assay and non-catheter urinary isolates as comparator.
292. Proportion of catheter-associated urinary tract infections meeting multidrug-resistant criteria, using routine susceptibility testing with organism-specific resistance assessed at final reporting over a twelve-month surveillance period.
293. Audit of urinary catheter indication and maintenance practices against institutional infection-control standards, with compliance and catheter-associated urinary tract infection rates assessed monthly over six months.

Central Line-Associated Bloodstream Infection

294. Incidence density and microbiological profile of central line-associated bloodstream infection in adult intensive care units, using standardized surveillance definitions with infections and central-line days recorded over twelve months.
295. Species distribution and antimicrobial susceptibility of central line-associated bloodstream infection isolates, using automated blood culture and routine susceptibility testing with resistance proportions assessed during the index admission.
296. Association of central venous catheter duration with central line-associated bloodstream infection, using catheterized patients without infection as comparator and device-days assessed until infection or line removal.
297. Association of femoral versus non-femoral central venous catheter placement with central line-associated bloodstream infection, using routine clinical records and infection occurrence assessed during catheterisation.
298. Association of prior broad-spectrum antibiotic exposure with multidrug-resistant central line-associated bloodstream infection, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
299. Association of biofilm formation with central line-associated bloodstream infection among staphylococci, using microtitre plate assay and non-device bloodstream isolates as comparator.
300. Association of central line-associated bloodstream infection with in-hospital mortality, using catheterized patients without bloodstream infection as comparator and outcome assessed at discharge.
301. Audit of central-line insertion and maintenance bundle compliance, using institutional standards with compliance proportions and central line-associated bloodstream infection incidence assessed monthly over six months.

Ventilator-Associated Pneumonia

302. Incidence density and microbiological profile of ventilator-associated pneumonia in adult intensive care units, using standardized surveillance definitions with infections and ventilator-days recorded prospectively over twelve months.
303. Species distribution and antimicrobial susceptibility of ventilator-associated pneumonia pathogens, using quantitative or semiquantitative lower respiratory culture with resistance proportions assessed at final laboratory reporting.
304. Association of ventilation duration with ventilator-associated pneumonia, using mechanically ventilated patients without pneumonia as comparator and ventilator-days assessed until infection or extubation.
305. Association of prior broad-spectrum antibiotic exposure with multidrug-resistant ventilator-associated pneumonia, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
306. Association of carbapenem-resistant Acinetobacter baumannii ventilator-associated pneumonia with mortality, using carbapenem-susceptible infection as comparator and outcome assessed at discharge.
307. Association of biofilm formation with ventilator-associated pneumonia caused by Pseudomonas aeruginosa, using microtitre plate assay and non-ventilator respiratory isolates as comparator.
308. Diagnostic agreement between endotracheal aspirate semiquantitative culture and clinical surveillance criteria for ventilator-associated pneumonia, with microbiological and clinical classification assessed during the same episode.
309. Audit of ventilator care bundle compliance, using institutional infection-control standards with monthly compliance and ventilator-associated pneumonia incidence assessed over six months.

Surgical Site Infection

310. Incidence and microbiological profile of surgical site infection among patients undergoing selected major operations, using standardized surveillance definitions with infection occurrence assessed during admission or thirty-day follow-up.
311. Species distribution and antimicrobial susceptibility of bacterial isolates from surgical site infections, using routine culture and susceptibility testing with resistance proportions assessed at final reporting.
312. Association of diabetes mellitus with surgical site infection, using operated patients without infection as comparator and infection occurrence assessed during admission or thirty days.
313. Association of preoperative antibiotic timing with surgical site infection, using guideline-concordant timing as comparator and infection occurrence assessed within thirty days.
314. Association of prolonged preoperative hospitalisation with surgical site infection, using shorter-stay operated patients as comparator and infection occurrence assessed within thirty days.
315. Association of multidrug-resistant surgical site infection with prolonged hospital stay, using susceptible surgical site infections as comparator and length of stay measured until discharge.
316. Association of biofilm formation with surgical site infection caused by Staphylococcus aureus, using microtitre plate assay and non-surgical wound isolates as comparator.
317. Audit of surgical antimicrobial prophylaxis against institutional guidelines, with appropriateness and subsequent surgical site infection documented during admission or thirty days.

Hospital-Acquired Pneumonia

318. Incidence and microbiological profile of hospital-acquired pneumonia among non-ventilated adult inpatients, using standardized clinical criteria and respiratory culture with infections assessed during hospitalisation.
319. Species distribution and antimicrobial susceptibility of hospital-acquired pneumonia pathogens, using acceptable-quality lower respiratory specimens with resistance proportions assessed at final reporting.
320. Association of prior antibiotic exposure with multidrug-resistant hospital-acquired pneumonia, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
321. Association of hospital-acquired pneumonia caused by carbapenem-resistant Gram-negative bacilli with mortality, using susceptible Gram-negative infections as comparator and outcome assessed at discharge.
322. Association of prolonged hospitalisation before onset with multidrug-resistant hospital-acquired pneumonia, using non-multidrug-resistant infection as comparator and days before pneumonia onset assessed prospectively.
323. Diagnostic utility of sputum Gram-stain quality scoring in hospital-acquired pneumonia, using significant respiratory culture as reference with sensitivity and specificity assessed at forty-eight hours.

Device-Associated Infections

324. Incidence density and microbiological spectrum of device-associated infections across adult intensive care units, using standardized surveillance definitions with device-days and infection episodes recorded prospectively.
325. Association of device duration with device-associated infection across urinary catheters, central venous catheters, and mechanical ventilation, using uninfected device episodes as comparator.
326. Association of biofilm-forming bacterial isolates with device-associated infection, using microtitre plate assay and non-device infections as comparator with biofilm strength assessed after isolate characterization.
327. Association of multidrug resistance with device-associated infection among Gram-negative bacilli, using non-device infections as comparator and routine susceptibility assessed at final reporting.
328. Association of device-associated infection with intensive care unit length of stay, using uninfected device-exposed patients as comparator and stay measured until discharge.
329. Audit of device necessity documentation and daily review practices, using institutional standards with compliance and device-associated infection occurrence assessed over six months.

ICU-Acquired Infections

330. Incidence and microbiological spectrum of intensive care unit-acquired infections among adult patients, using standardized surveillance definitions with infection episodes assessed over twelve months.
331. Species distribution and antimicrobial resistance of intensive care unit-acquired bacterial infections, using routine cultures and susceptibility testing with resistance proportions assessed at final reporting.
332. Association of prolonged intensive care unit stay with acquisition of multidrug-resistant infection, using patients without multidrug-resistant infection as comparator and exposure time assessed before culture positivity.
333. Association of invasive-device exposure with intensive care unit-acquired infection, using uninfected intensive care unit patients as comparator and device exposure assessed before infection onset.
334. Association of intensive care unit-acquired carbapenem-resistant Gram-negative infection with mortality, using susceptible Gram-negative infection as comparator and outcome assessed at discharge.
335. Retrospective three-year surveillance of intensive care unit-acquired infections, using microbiology and infection-control records with annual incidence, pathogen distribution, and resistance patterns compared by calendar year.

Infection Prevention and Control

Hand Hygiene

336. Hand hygiene compliance among healthcare workers in intensive care and general wards, using direct observation against World Health Organization moments with compliance proportions assessed over six months: a prospective audit.
337. Comparison of hand hygiene compliance between doctors, nurses, and support staff, using standardized direct observation with profession-specific compliance assessed during the same surveillance period.
338. Association of hand hygiene compliance with healthcare-associated infection rates across selected wards, using monthly observation scores and infection surveillance data assessed over six months.
339. Microbiological assessment of healthcare worker hand contamination before and after routine hand hygiene, using consented hand cultures with colony-count reduction measured immediately.
340. Association of hand hygiene training with subsequent compliance, using staff with and without recent training as comparator and compliance assessed by direct observation over three months.

Standard Precautions

341. Compliance with standard precautions among healthcare workers in high-risk hospital areas, using a structured observational checklist with domain-specific compliance assessed over six months.
342. Association of standard precaution knowledge scores with observed compliance among healthcare workers, using questionnaire and direct observation performed during the same study period.
343. Compliance with appropriate personal protective equipment use during routine clinical procedures, using institutional standards as reference with correct-use proportions assessed over three months.
344. Audit of blood and body-fluid spill management against institutional standard precautions, with process compliance and corrective actions assessed over six months.

Transmission-Based Precautions

345. Compliance with contact precautions for patients colonized or infected with multidrug-resistant organisms, using institutional guidelines with adherence assessed through direct observation over six months.
346. Compliance with airborne precautions for patients with suspected or confirmed pulmonary tuberculosis, using institutional policy with isolation and respirator-use adherence assessed during admission.
347. Compliance with droplet precautions among patients with laboratory-confirmed respiratory viral infection, using hospital guidelines with adherence assessed during the infectious period.
348. Association of transmission-based precaution compliance with secondary multidrug-resistant organism acquisition in high-risk wards, using ward surveillance cultures and infection-control observations assessed during admission.

Biomedical Waste Management

349. Knowledge and practice of biomedical waste segregation among healthcare workers, using national biomedical waste rules as reference with knowledge scores and observed compliance assessed cross-sectionally.
350. Audit of biomedical waste segregation at point of generation across hospital areas, using national standards with category-specific error rates assessed over three months.
351. Association of healthcare worker training with biomedical waste segregation compliance, using recently trained and untrained staff as comparator with direct observation performed during the study period.
352. Audit of microbiology laboratory biomedical waste handling from generation to disposal, using institutional protocol with nonconformities assessed over six months.
353. Frequency and types of biomedical waste segregation errors in high-risk hospital areas, using direct observation with monthly error patterns assessed over six months.

Environmental Surveillance

354. Microbiological surveillance of high-touch intensive care unit surfaces before and after routine cleaning, using standardized cultures with colony-count reduction and pathogen recovery assessed immediately.
355. Association of environmental contamination with nearby patient infection by the same bacterial species, using routine surface cultures and clinical isolates with temporal overlap assessed during admission.
356. Comparison of bacterial contamination on high-touch surfaces across intensive care, emergency, and general wards, using standardized culture methods with colony counts assessed on the same sampling schedule.
357. Microbiological surveillance of hospital sinks and wet surfaces for multidrug-resistant Gram-negative bacilli, using routine culture with organism distribution and susceptibility assessed at final reporting.
358. Audit of environmental cleaning quality using microbiological surface sampling, with pre-cleaning and post-cleaning colony counts compared monthly over six months.

Disinfection and Sterilization

359. Agreement between biological, chemical, and mechanical monitoring of steam sterilization cycles, using routine central sterilization records with discordance assessed after each monitored cycle.
360. Audit of high-level disinfection of flexible endoscopes against institutional protocol, with procedural compliance and post-disinfection culture positivity assessed over six months.
361. Microbiological evaluation of reusable clinical equipment before and after routine disinfection, using standardized cultures with colony-count reduction assessed immediately after processing.
362. Association of disinfectant dilution accuracy with environmental decontamination efficacy, using concentration checks and post-cleaning surface cultures assessed during the same cleaning episode.
363. Audit of sterilization indicator failures and corrective actions, using departmental procedures as reference with failure causes and action completion assessed over six months.

Healthcare Worker Surveillance

364. Prevalence of nasal Staphylococcus aureus carriage among healthcare workers in high-risk wards, using consented nasal swabs with methicillin resistance assessed at final laboratory reporting.
365. Association of healthcare work area with methicillin-resistant Staphylococcus aureus nasal carriage, using staff from general wards as comparator and carriage assessed at enrollment.
366. Hepatitis B surface antibody protection among vaccinated healthcare workers, using quantitative serology with vaccination history and time since last dose assessed cross-sectionally.
367. Audit of healthcare worker vaccination status for hepatitis B and other institutionally recommended vaccines, using occupational health records with coverage assessed at enrollment.

Needle-Stick Injuries

368. Incidence and circumstances of needle-stick injuries among healthcare workers, using occupational health records with procedure type, device, and post-exposure management assessed over two years.
369. Association of professional category with needle-stick injury risk, using hospital workforce denominators and documented injury episodes assessed over twelve months.
370. Audit of post-exposure prophylaxis initiation after needle-stick injuries, using institutional protocols with appropriateness and time to first dose assessed for each reported exposure.
371. Knowledge and reporting practices regarding needle-stick injuries among healthcare workers, using a structured questionnaire with prior exposure and reporting behaviour assessed cross-sectionally.

Infection Control Audits

372. Audit of infection-control practices in intensive care units using a standardized checklist, with domain-specific compliance and healthcare-associated infection rates assessed monthly over six months.
373. Audit of isolation-room practice for patients with multidrug-resistant organisms, using institutional standards with adherence assessed through direct observation over three months.
374. Audit of catheter, central-line, and ventilator bundle compliance across intensive care units, using standardized checklists with monthly adherence compared with device-associated infection rates.
375. Audit of infection-control documentation after detection of a healthcare-associated infection, using institutional requirements with completeness and timeliness assessed over twelve months.

Antimicrobial Stewardship

Antibiotic Prescription Patterns

376. Pattern and appropriateness of antibiotic prescribing among adult inpatients, using institutional or national antimicrobial guidelines as reference with appropriateness assessed within twenty-four hours of prescription.
377. Antibiotic prescribing patterns in intensive care units, using treatment records with indication, spectrum, route, and duration assessed during the first seventy-two hours of therapy.
378. Antibiotic prescription patterns for community-acquired pneumonia, using guideline recommendations as comparator with drug choice and duration assessed during the index admission.
379. Antibiotic prescription patterns for urinary tract infection, using culture results and guideline recommendations with appropriateness assessed at initiation and after microbiology reporting.
380. Association of broad-spectrum antibiotic prescribing with prior hospitalisation, using patients receiving narrow-spectrum therapy as comparator and healthcare exposure assessed at admission.
381. Audit of duplicate anaerobic or Gram-negative antimicrobial coverage among inpatients, using stewardship criteria with unnecessary duplicate therapy assessed during the first seventy-two hours.

Empirical Antibiotic Therapy

382. Appropriateness of empirical antibiotic therapy in adult sepsis, using final culture and susceptibility results as comparator with concordance assessed when microbiology results become available.
383. Association of inappropriate empirical antibiotic therapy with mortality among culture-confirmed bloodstream infections, using appropriate empirical therapy as comparator and outcome assessed at discharge.
384. Appropriateness of empirical therapy for intensive care unit-acquired Gram-negative infection, using final antimicrobial susceptibility as reference with concordance assessed after culture reporting.
385. Association of prior antibiotic exposure with inappropriate empirical therapy in multidrug-resistant Gram-negative infection, using appropriate therapy as comparator and prior exposure assessed over ninety days.
386. Concordance of empirical therapy with local antibiogram recommendations for common bacterial syndromes, using final susceptibility results and appropriateness assessed at culture reporting.
387. Time from sepsis recognition to first effective empirical antibiotic among culture-confirmed cases, using final susceptibility results to define effective therapy and timing assessed from hospital records.

Culture-Guided Therapy

388. Proportion of culture-positive infections receiving microbiology-guided antibiotic modification, using medication records with therapy changes assessed within forty-eight hours of final susceptibility reporting.
389. Association of culture-guided therapy with antibiotic-spectrum reduction, using patients without therapy modification as comparator and spectrum change assessed within forty-eight hours of susceptibility reporting.
390. Association of culture-guided therapy with hospital length of stay among bacterial infections, using empirically continued therapy as comparator and stay measured until discharge.
391. Association of culture-guided effective therapy with mortality in Gram-negative bloodstream infection, using discordant therapy as comparator and outcome assessed at discharge.
392. Time from final susceptibility report to appropriate antibiotic modification among hospitalised patients, using electronic or paper medication records with delays measured prospectively.
393. Proportion of positive urine cultures leading to clinically appropriate therapy modification, using treatment records and guideline criteria with changes assessed within forty-eight hours.

De-Escalation

394. Frequency of antibiotic de-escalation after culture and susceptibility results among adult inpatients, using stewardship criteria with de-escalation assessed within forty-eight hours of reporting.
395. Association of culture positivity with antibiotic de-escalation in sepsis, using culture-negative sepsis as comparator and therapy modification assessed within seventy-two hours.
396. Predictors of failure to de-escalate broad-spectrum antibiotics despite susceptible culture results, using de-escalated patients as comparator and prescribing factors assessed within seventy-two hours.
397. Association of de-escalation with total antibiotic days among culture-confirmed infections, using continued broad-spectrum therapy as comparator and antibiotic duration measured until discharge.
398. Association of antimicrobial de-escalation with clinical outcome among stable culture-confirmed patients, using non-de-escalated therapy as comparator and mortality assessed at discharge.

Antibiotic Consumption

399. Antibiotic consumption in adult intensive care units using defined daily doses per one thousand patient-days, with monthly class-specific consumption trends assessed over twelve months: a retrospective drug-utilisation study.
400. Antibiotic consumption in general medical wards using defined daily doses per one thousand patient-days, with monthly class-specific use assessed over twelve months.
401. Association of carbapenem consumption with carbapenem-resistant Gram-negative isolation rates, using monthly pharmacy and microbiology data correlated over twelve months.
402. Association of third-generation cephalosporin consumption with extended spectrum beta lactamase-producing Enterobacterales rates, using monthly pharmacy and laboratory data assessed over twelve months.
403. Comparison of antibiotic consumption between intensive care and general wards, using defined daily doses per one thousand patient-days with class-specific differences assessed over twelve months.

Restricted Antibiotics

404. Audit of restricted antibiotic prescriptions against hospital approval criteria, with indication, authorization, and microbiological support assessed at initiation and within seventy-two hours.
405. Appropriateness of carbapenem prescribing among adult inpatients, using institutional stewardship criteria with indication and microbiological justification assessed during the first seventy-two hours.
406. Appropriateness of colistin prescribing among patients with multidrug-resistant Gram-negative infection, using culture susceptibility and stewardship criteria with indication assessed before treatment initiation.
407. Frequency of restricted antibiotic continuation despite negative cultures, using stewardship criteria with continued use assessed at seventy-two hours after microbiology sampling.
408. Association of infectious disease or stewardship approval with appropriate restricted antibiotic use, using unreviewed prescriptions as comparator and appropriateness assessed within seventy-two hours.

Antibiograms

409. Development of an annual cumulative hospital antibiogram for major bacterial pathogens, using first isolates per patient and current susceptibility standards with resistance proportions calculated for the preceding twelve months.
410. Comparison of intensive care unit and general-ward antibiograms for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii using annual susceptibility data from the same period.
411. Comparison of urine and bloodstream antibiograms for common Enterobacterales, using first isolates per patient with specimen-specific susceptibility proportions assessed over twelve months.
412. Comparison of community-onset and hospital-acquired antibiograms for major uropathogens, using clinical acquisition criteria and routine susceptibility data from the same annual period.
413. Three-year trend analysis of hospital antibiograms for major Gram-negative pathogens, using annual cumulative susceptibility data with statistically significant changes assessed by calendar year.
414. Development of a syndrome-specific antibiogram for bloodstream infections, using first clinically significant isolates per patient with pathogen-specific susceptibility proportions assessed over twelve months.

Stewardship Interventions

415. Before-and-after audit of antibiotic prescription quality following dissemination of a local antibiogram, using guideline-concordant prescribing as outcome assessed during equal three-month periods.
416. Before-and-after evaluation of stewardship feedback on carbapenem prescribing, using appropriateness and days of therapy as outcomes assessed during equal three-month periods without altering individual patient treatment.
417. Effect of routine microbiology comment reporting on antibiotic de-escalation, using pre-implementation and post-implementation records with de-escalation frequency assessed within seventy-two hours of susceptibility reporting.
418. Before-and-after audit of intravenous-to-oral antibiotic switch practice following a stewardship checklist, using eligibility criteria and timely switch proportions assessed during equal study periods.
419. Association of stewardship review with restricted antibiotic duration, using reviewed and unreviewed prescriptions as comparator and therapy days measured until discontinuation or discharge.
420. Retrospective evaluation of antimicrobial stewardship recommendations and clinician acceptance, using program records with recommendation type, acceptance, and therapy modification assessed within forty-eight hours.

Bloodstream Infections

Bacteraemia

421. Spectrum and antimicrobial susceptibility of bacterial bloodstream isolates among adult inpatients, using automated blood culture and routine susceptibility testing with resistance proportions assessed during the index admission.
422. Association of blood culture time to positivity with Gram-positive versus Gram-negative bacteraemia, using final organism identification and automated detection times assessed during the same culture episode.
423. Association of blood culture time to positivity with in-hospital mortality among monomicrobial bacteraemia, using automated culture data and discharge outcome from the same admission.
424. Association of prior antibiotic exposure with blood culture positivity in suspected bacteraemia, using antibiotic-unexposed patients as comparator and exposure documented before specimen collection.
425. Association of number of blood culture sets with pathogen recovery, using patients with one set as comparator and incremental diagnostic yield assessed during the same febrile episode.
426. Retrospective three-year trend of bloodstream bacterial isolates and antimicrobial resistance, using laboratory records with annual pathogen distribution and susceptibility proportions compared by calendar year.

Septicaemia

427. Microbiological profile and antimicrobial susceptibility of culture-confirmed septicemia among hospitalised adults, using blood culture and routine susceptibility testing with organism distribution assessed during the index admission.
428. Association of multidrug-resistant septicemia with in-hospital mortality, using susceptible bloodstream infections as comparator and outcome assessed at discharge: a retrospective analytical study.
429. Association of delayed effective antimicrobial therapy with mortality in culture-confirmed septicemia, using timely effective therapy as comparator and treatment timing assessed from medication records.
430. Association of septicemia caused by carbapenem-resistant Gram-negative bacilli with intensive care unit admission, using susceptible Gram-negative septicemia as comparator and clinical course assessed during hospitalisation.
431. Association of polymicrobial septicemia with mortality, using monomicrobial bloodstream infection as comparator and outcome assessed at discharge.

Sepsis

432. Diagnostic performance of procalcitonin for blood culture positivity among adults with suspected sepsis where routinely measured, using blood culture as reference with values obtained within twenty-four hours.
433. Diagnostic performance of C-reactive protein for blood culture positivity among adults with suspected sepsis, using blood culture as reference with values obtained within twenty-four hours.
434. Association of neutrophil-to-lymphocyte ratio with mortality among culture-confirmed sepsis patients, using admission blood counts and discharge outcome during the same hospitalisation.
435. Association of thrombocytopenia with Gram-negative sepsis, using Gram-positive bloodstream infection as comparator and platelet counts obtained within twenty-four hours.
436. Association of multidrug-resistant bloodstream infection with septic shock, using susceptible bloodstream infection as comparator and shock status assessed within twenty-four hours of culture positivity.
437. Association of blood culture time to positivity with septic shock among monomicrobial bacteraemia, using automated culture and clinical status documented within twenty-four hours.
438. Comparative inflammatory-marker profiles in Gram-positive and Gram-negative culture-confirmed sepsis, using final organism identification and laboratory values measured within twenty-four hours.

Blood Culture Contamination

439. Blood culture contamination rate and organism profile in emergency and inpatient wards, using predefined contamination criteria with monthly rates assessed over twelve months.
440. Association of collection site with blood culture contamination, using peripheral venipuncture and catheter-drawn samples where clinically obtained with contamination classification assessed at final review.
441. Association of collector professional category with blood culture contamination, using routine collection records and contamination rates assessed over six months.
442. Association of antiseptic preparation compliance with blood culture contamination, using direct observation and final culture classification assessed during the same surveillance period.
443. Clinical and laboratory characteristics distinguishing coagulase-negative staphylococcal contamination from true bloodstream infection, using predefined adjudication criteria with classification completed during admission.

Gram-Positive Bloodstream Infection

444. Species distribution and antimicrobial susceptibility of Gram-positive bloodstream isolates, using automated blood culture and routine susceptibility testing with resistance proportions assessed during the index admission.
445. Association of methicillin-resistant Staphylococcus aureus bacteraemia with mortality, using methicillin-susceptible Staphylococcus aureus bacteraemia as comparator and outcome assessed at discharge.
446. Association of persistent Staphylococcus aureus bacteraemia with longer time to effective therapy, using cleared bacteraemia as comparator and repeat culture status assessed within seven days.
447. Clinical significance of Enterococcus faecalis and Enterococcus faecium bloodstream infections, using routine culture and susceptibility testing with mortality assessed during the index admission.
448. Association of vancomycin-resistant Enterococcus bloodstream infection with mortality, using vancomycin-susceptible Enterococcus infection as comparator and outcome assessed at discharge.

Gram-Negative Bloodstream Infection

449. Species distribution and antimicrobial susceptibility of Gram-negative bloodstream isolates, using automated blood culture and routine susceptibility testing with resistance proportions assessed during the index admission.
450. Association of carbapenem-resistant Enterobacterales bloodstream infection with mortality, using carbapenem-susceptible Enterobacterales as comparator and outcome assessed at discharge.
451. Association of extended spectrum beta lactamase-producing Escherichia coli bacteraemia with prior healthcare exposure, using non-producing bacteraemia as comparator and exposure assessed during the preceding ninety days.
452. Association of carbapenem-resistant Klebsiella pneumoniae bacteraemia with delayed effective therapy, using susceptible bacteraemia as comparator and treatment timing assessed after culture positivity.
453. Association of Pseudomonas aeruginosa bloodstream infection with intensive care unit exposure, using other Gram-negative bacteraemia as comparator and ward location assessed before culture positivity.
454. Association of multidrug-resistant Gram-negative bacteraemia with prolonged hospitalisation, using susceptible bacteraemia as comparator and length of stay measured until discharge.

Fungaemia

455. Species distribution and antifungal susceptibility of Candida bloodstream isolates, using routine blood culture identification and susceptibility testing with resistance proportions assessed during the index admission.
456. Association of candidemia with central venous catheter exposure, using matched blood culture-negative high-risk patients as comparator and device exposure assessed before culture positivity.
457. Association of non-albicans Candida bloodstream infection with prior antifungal exposure, using Candida albicans bloodstream infection as comparator and exposure assessed during the preceding ninety days.
458. Association of candidemia with in-hospital mortality, using comparable high-risk patients without candidemia as comparator and outcome assessed at discharge.

Neonatal Sepsis

459. Microbiological profile and antimicrobial susceptibility of early- and late-onset neonatal sepsis, using automated blood culture with organism distribution and resistance assessed during the index admission.
460. Association of low birth weight with culture-confirmed neonatal sepsis, using culture-negative neonates evaluated for sepsis as comparator and birth weight recorded at admission.
461. Association of prematurity with culture-confirmed neonatal sepsis, using term neonates evaluated for sepsis as comparator and infection status determined during the same admission.
462. Association of multidrug-resistant Gram-negative neonatal sepsis with mortality, using susceptible Gram-negative sepsis as comparator and outcome assessed at discharge.
463. Association of central-line exposure with late-onset neonatal sepsis, using non-infected hospitalised neonates as comparator and device exposure assessed before culture positivity.
464. Blood culture contamination rate in neonatal intensive care units, using predefined contamination criteria with monthly rates and common contaminating organisms assessed over twelve months.
465. Retrospective three-year trend of neonatal bloodstream pathogens and antimicrobial resistance, using laboratory records with annual organism distribution and susceptibility proportions compared by calendar year.

Respiratory Tract Infections

Community-Acquired Pneumonia

466. Microbiological profile of community-acquired pneumonia among hospitalised adults, using acceptable-quality respiratory culture and routine diagnostics with pathogen distribution assessed during the index admission.
467. Association of positive sputum culture with clinical severity in community-acquired pneumonia, using culture-negative pneumonia as comparator and severity measures assessed at admission.
468. Antimicrobial susceptibility of bacterial pathogens causing community-acquired pneumonia, using routine respiratory culture with organism-specific resistance proportions assessed at final reporting.
469. Diagnostic accuracy of sputum Gram staining for bacterial community-acquired pneumonia, using significant respiratory culture as reference with sensitivity and specificity assessed at forty-eight hours.
470. Association of prior outpatient antibiotic use with negative sputum culture in community-acquired pneumonia, using antibiotic-unexposed patients as comparator and exposure assessed before specimen collection.
471. Association of multidrug-resistant community-acquired pneumonia pathogens with prior healthcare exposure, using susceptible pathogens as comparator and exposure during the preceding ninety days assessed from records.

Hospital-Acquired Pneumonia

472. Microbiological profile and antimicrobial susceptibility of hospital-acquired pneumonia in non-ventilated adults, using lower respiratory culture with pathogen distribution assessed during the index admission.
473. Association of prior broad-spectrum antibiotic use with multidrug-resistant hospital-acquired pneumonia, using susceptible infection as comparator and exposure assessed during the preceding ninety days.
474. Association of hospital-acquired pneumonia caused by carbapenem-resistant Gram-negative bacilli with mortality, using susceptible infections as comparator and outcome assessed at discharge.
475. Association of duration of hospitalisation before pneumonia onset with multidrug resistance, using non-multidrug-resistant hospital-acquired pneumonia as comparator and pre-infection days assessed prospectively.
476. Diagnostic utility of sputum quality scoring in hospital-acquired pneumonia, using significant bacterial culture as reference with sensitivity and specificity assessed at final reporting.

Ventilator-Associated Pneumonia

477. Incidence density and microbiological profile of ventilator-associated pneumonia, using standardized surveillance criteria with infections and ventilator-days recorded prospectively over twelve months.
478. Association of ventilation duration with ventilator-associated pneumonia, using ventilated patients without infection as comparator and device-days assessed until pneumonia or extubation.
479. Species distribution and antimicrobial susceptibility of ventilator-associated pneumonia pathogens, using endotracheal aspirate culture with resistance proportions assessed at final reporting.
480. Association of multidrug-resistant ventilator-associated pneumonia with mortality, using susceptible ventilator-associated pneumonia as comparator and outcome assessed at discharge.
481. Association of prior carbapenem exposure with carbapenem-resistant ventilator-associated pneumonia, using carbapenem-susceptible infection as comparator and exposure assessed during the preceding ninety days.

Tuberculosis

482. Diagnostic accuracy of sputum smear microscopy for pulmonary tuberculosis, using cartridge based nucleic acid amplification testing or culture as reference with performance assessed during the same diagnostic episode.
483. Association of tuberculosis molecular bacterial burden with radiological severity, using cartridge based nucleic acid amplification test category and chest imaging obtained at diagnosis.
484. Association of diabetes mellitus with smear positivity among microbiologically confirmed pulmonary tuberculosis, using non-diabetic cases as comparator and smear results assessed at diagnosis.
485. Association of human immunodeficiency virus infection with smear-negative pulmonary tuberculosis, using human immunodeficiency virus-negative cases as comparator and microbiological findings assessed during the initial evaluation.
486. Turnaround time comparison of smear microscopy and molecular tuberculosis testing in respiratory specimens, measuring time from laboratory receipt to verified report prospectively.
487. Retrospective trend of pulmonary tuberculosis positivity and rifampicin resistance among respiratory specimens, using laboratory records with annual proportions assessed over three years.

Viral Respiratory Infections

488. Prevalence and seasonal distribution of respiratory viruses among hospitalised patients with acute respiratory illness, using routine molecular testing with monthly positivity assessed over twelve months.
489. Association of influenza virus infection with intensive care unit admission, using influenza-negative respiratory illness as comparator and outcome assessed during the index admission.
490. Association of respiratory syncytial virus infection with oxygen requirement in hospitalised children, using virus-negative respiratory illness as comparator and support assessed during admission.
491. Agreement between rapid antigen and molecular testing for severe acute respiratory syndrome coronavirus 2, using molecular testing as reference with sensitivity assessed on the same specimen.
492. Diagnostic yield of multiplex respiratory viral testing compared with targeted conventional tests, using hospitalised patients with additional pathogen detections assessed during the same episode.
493. Comparative clinical severity of laboratory-confirmed influenza virus, respiratory syncytial virus, and severe acute respiratory syndrome coronavirus 2 infections, using discharge outcomes during the index admission.

Fungal Respiratory Infections

494. Diagnostic yield of fungal culture in patients with suspected fungal lower respiratory infection, using composite clinical diagnosis as comparator with positivity assessed at final culture reporting.
495. Association of Aspergillus isolation from respiratory specimens with structural lung disease, using culture-negative suspected fungal infection as comparator and clinical diagnosis assessed during admission.
496. Association of respiratory Candida isolation with mechanical ventilation, using non-ventilated patients as comparator and colonization versus infection classified during the same admission.
497. Diagnostic performance of galactomannan testing where routinely available for suspected pulmonary aspergillosis, using composite diagnosis as reference with sensitivity assessed during hospitalisation.
498. Spectrum of moulds isolated from lower respiratory specimens in immunocompromised patients, using routine culture identification with clinical significance assessed during the index admission.

Lower Respiratory Tract Specimen Microbiology

499. Association of sputum Gram-stain quality score with recovery of clinically significant bacterial pathogens, using final respiratory culture as reference with diagnostic performance assessed at forty-eight hours.
500. Inter-observer agreement in sputum quality assessment by Gram staining, using senior microbiologist consensus as reference with kappa assessed before culture results are available.
501. Comparative pathogen yield of sputum and endotracheal aspirate specimens in clinically indicated lower respiratory infection, with specimen-specific recovery assessed at final culture reporting.
502. Association of specimen transport delay with bacterial culture yield from lower respiratory samples, using promptly processed specimens as comparator and pathogen recovery assessed at forty-eight hours.
503. Association of prior antibiotic exposure with lower respiratory culture negativity, using antibiotic-unexposed patients as comparator and exposure assessed before specimen collection.
504. Diagnostic accuracy of direct Gram stain for predominant organism morphology in lower respiratory specimens, using final culture identification as reference with concordance assessed at reporting.
505. Audit of lower respiratory specimen rejection based on microscopy quality criteria, using laboratory standards with rejection rates and subsequent diagnostic yield assessed over six months.

Urinary Tract Infections

Community-Acquired UTI

506. Microbiological profile and antimicrobial susceptibility of community-acquired urinary tract infection among adults, using quantitative urine culture with organism-specific resistance proportions assessed at final reporting.
507. Prevalence of extended spectrum beta lactamase-producing Escherichia coli in community-acquired urinary tract infection, using phenotypic confirmatory testing with resistance patterns assessed after isolate characterization.
508. Association of recent antibiotic exposure with resistant community-acquired urinary tract infection, using susceptible infections as comparator and exposure during the preceding ninety days assessed from records.
509. Association of diabetes mellitus with multidrug-resistant community-acquired urinary tract infection, using non-diabetic patients as comparator and resistance status assessed at final laboratory reporting.
510. Diagnostic accuracy of direct urine Gram stain for community-acquired urinary tract infection, using significant quantitative culture as reference with sensitivity and specificity assessed at forty-eight hours.
511. Retrospective three-year trend of community-acquired uropathogens and antimicrobial susceptibility, using laboratory records with annual organism distribution and resistance proportions compared by calendar year.

Hospital-Acquired UTI

512. Microbiological profile and antimicrobial susceptibility of hospital-acquired urinary tract infection, using quantitative urine culture with pathogen distribution and resistance proportions assessed during admission.
513. Association of hospitalisation duration with multidrug-resistant hospital-acquired urinary tract infection, using susceptible infections as comparator and pre-infection hospital days assessed before culture positivity.
514. Association of prior broad-spectrum antibiotic exposure with carbapenem-resistant hospital-acquired urinary tract infection, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
515. Association of hospital-acquired urinary tract infection caused by multidrug-resistant organisms with prolonged length of stay, using susceptible infection as comparator and stay measured until discharge.
516. Comparison of community-acquired and hospital-acquired urinary tract infection antibiograms, using routine susceptibility data with organism-specific resistance proportions assessed over the same twelve-month period.

Catheter-Associated UTI

517. Incidence density and microbiological profile of catheter-associated urinary tract infection, using standardized surveillance definitions with infection episodes and catheter-days recorded prospectively over twelve months.
518. Association of urinary catheter duration with catheter-associated urinary tract infection, using catheterized non-infected patients as comparator and device-days assessed until infection or catheter removal.
519. Association of biofilm formation with catheter-associated urinary tract infection among Escherichia coli isolates, using microtitre plate assay and non-catheter urinary isolates as comparator.
520. Association of biofilm formation with catheter-associated urinary tract infection among Klebsiella pneumoniae isolates, using microtitre plate assay and non-catheter urinary isolates as comparator.
521. Association of prior antibiotic exposure with multidrug-resistant catheter-associated urinary tract infection, using susceptible infection as comparator and exposure assessed during the preceding ninety days.
522. Audit of catheter indication and maintenance practices, using institutional standards with compliance and catheter-associated urinary tract infection incidence assessed over six months.

Recurrent UTI

523. Microbiological profile of recurrent urinary tract infection among adult women, using quantitative culture with organism distribution and antimicrobial susceptibility assessed during recurrent episodes.
524. Association of extended spectrum beta lactamase-producing Escherichia coli with recurrent urinary tract infection, using first-episode infections as comparator and recurrence documented within six months.
525. Association of biofilm formation with recurrent Escherichia coli urinary tract infection, using microtitre plate assay and first-episode isolates as comparator with recurrence assessed within six months.
526. Association of diabetes mellitus with recurrent urinary tract infection, using non-recurrent culture-confirmed infection as comparator and recurrence documented over six months.
527. Antimicrobial susceptibility changes between initial and recurrent urinary isolates from the same patient, using paired cultures with categorical changes assessed within six months.

Complicated UTI

528. Microbiological profile and antimicrobial susceptibility of complicated urinary tract infection among hospitalised adults, using quantitative culture with organism distribution assessed at final reporting.
529. Association of structural urinary tract abnormality with multidrug-resistant complicated urinary tract infection, using patients without documented abnormality as comparator and resistance assessed at final reporting.
530. Association of diabetes mellitus with multidrug-resistant complicated urinary tract infection, using non-diabetic cases as comparator and susceptibility profiles assessed during the same episode.
531. Association of prior urological instrumentation with resistant complicated urinary tract infection, using non-instrumented patients as comparator and procedures during the preceding ninety days assessed from records.
532. Association of complicated urinary tract infection caused by carbapenem-resistant Enterobacterales with prolonged hospitalisation, using susceptible infection as comparator and stay measured until discharge.
533. Species distribution of non-Escherichia coli uropathogens in complicated urinary tract infection, using quantitative culture with susceptibility patterns assessed at final reporting.

Uropathogens

534. Distribution of uropathogens across age and sex groups among patients with significant bacteriuria, using quantitative urine culture with organism frequencies assessed at final reporting.
535. Comparative antimicrobial susceptibility of Escherichia coli and Klebsiella pneumoniae urinary isolates, using routine disc diffusion with resistance proportions assessed during the same annual period.
536. Prevalence of Enterococcus species among urinary tract infections, using quantitative culture with species distribution and antimicrobial susceptibility assessed at final reporting.
537. Prevalence and significance of Pseudomonas aeruginosa in urinary tract infection, using quantitative culture with catheterisation and healthcare exposure assessed during the same episode.
538. Association of polymicrobial urine culture with catheterisation, using monomicrobial significant bacteriuria as comparator and catheter status assessed at specimen collection.
539. Seasonal distribution of common uropathogens in a tertiary teaching hospital, using laboratory records with monthly organism frequencies assessed over two years.

Antimicrobial Resistance in Uropathogens

540. Prevalence of multidrug resistance among Escherichia coli urinary isolates, using routine susceptibility testing with resistance proportions assessed at final laboratory reporting: a cross-sectional study.
541. Prevalence of extended spectrum beta lactamase production among urinary Enterobacterales, using combination-disc testing with species-specific resistance profiles assessed after isolate characterization.
542. Prevalence of carbapenem resistance among Klebsiella pneumoniae urinary isolates, using routine susceptibility testing with associated resistance patterns assessed at final reporting.
543. Association of fluoroquinolone resistance with prior fluoroquinolone exposure among Escherichia coli urinary infections, using susceptible infections as comparator and exposure assessed during the preceding ninety days.
544. Comparison of outpatient and inpatient uropathogen antibiograms, using routine susceptibility data with organism-specific resistance proportions assessed over the same twelve-month period.
545. Three-year trend of antimicrobial resistance among urinary Escherichia coli, using laboratory susceptibility records with annual resistance proportions compared by calendar year.

Gastrointestinal Infections

Bacterial Diarrhoea

546. Microbiological profile of bacterial diarrhoea among patients submitting stool cultures, using routine enteric culture with pathogen distribution and antimicrobial susceptibility assessed at final reporting.
547. Association of bloody diarrhoea with bacterial stool culture positivity, using culture-negative diarrhoeal patients as comparator and clinical features recorded at presentation.
548. Antimicrobial susceptibility of Salmonella and Shigella isolates from stool specimens, using routine susceptibility testing with species-specific resistance proportions assessed at final reporting.
549. Association of recent antibiotic exposure with bacterial stool culture negativity, using antibiotic-unexposed diarrhoeal patients as comparator and exposure assessed before specimen collection.
550. Seasonal distribution of bacterial enteric pathogens in a teaching hospital, using routine stool culture records with monthly positivity proportions assessed over two years.

Viral Gastroenteritis

551. Prevalence of rotavirus antigen among children with acute gastroenteritis, using routine stool antigen testing with age and dehydration severity assessed during the same admission.
552. Association of rotavirus positivity with severe dehydration, using rotavirus-negative gastroenteritis as comparator and hydration status assessed at presentation.
553. Prevalence and seasonal distribution of norovirus where routinely tested among hospitalised gastroenteritis patients, using molecular assays with monthly positivity assessed over twelve months.
554. Prevalence of enteric adenovirus among children with acute gastroenteritis, using routine antigen or molecular detection with clinical severity assessed during the same episode.
555. Comparative clinical profiles of laboratory-confirmed viral and bacterial gastroenteritis in children, using routine diagnostic testing with dehydration and length of stay assessed during admission.

Parasitic Gastrointestinal Infections

556. Prevalence of intestinal parasites among patients with gastrointestinal symptoms, using direct microscopy and concentration methods with species distribution assessed at final reporting.
557. Diagnostic yield of concentration methods over direct wet mount for intestinal parasites, using cumulative microscopy as reference with additional detection assessed on the same stool specimen.
558. Association of persistent diarrhoea with Cryptosporidium infection, using parasite-negative diarrhoeal patients as comparator and modified acid-fast microscopy assessed during the same episode.
559. Association of immunosuppression with intestinal protozoal infection, using immunocompetent patients as comparator and parasite detection assessed by routine stool microscopy.
560. Comparative parasite prevalence among paediatric and adult stool specimens, using identical microscopy methods with age-specific positivity assessed during the same annual period.

Food-Borne Infections

561. Microbiological profile of suspected food-borne bacterial infection among hospitalised patients, using routine stool culture with pathogen distribution and exposure history assessed during the index episode.
562. Association of shared food exposure with isolation of enteric bacterial pathogens, using culture-negative diarrhoeal patients as comparator and exposure assessed during the preceding seventy-two hours.
563. Antimicrobial susceptibility of bacterial pathogens isolated from suspected food-borne infections, using routine susceptibility testing with resistance proportions assessed at final reporting.
564. Seasonal distribution of laboratory-confirmed food-borne bacterial infections, using routine stool culture records with monthly positivity patterns assessed over two years.
565. Retrospective laboratory review of clustered food-borne illness episodes, using microbiology records with pathogen concordance and temporal clustering assessed over three years.

Clostridioides difficile Infection

566. Prevalence of Clostridioides difficile toxin positivity among hospitalised adults with antibiotic-associated diarrhoea, using routine toxin testing with positivity assessed during the diarrhoeal episode.
567. Association of broad-spectrum antibiotic exposure with Clostridioides difficile infection, using toxin-negative antibiotic-associated diarrhoea as comparator and exposure assessed during the preceding ninety days.
568. Association of Clostridioides difficile infection with prolonged hospitalisation, using toxin-negative diarrhoeal patients as comparator and length of stay measured until discharge.
569. Association of Clostridioides difficile toxin positivity with leukocytosis and renal dysfunction, using laboratory parameters measured within twenty-four hours of diagnosis.
570. Retrospective trend of Clostridioides difficile testing and positivity, using laboratory records with annual test utilisation and positive proportions assessed over three years.

Enteric Fever

571. Blood culture positivity and antimicrobial susceptibility of Salmonella Typhi and Salmonella Paratyphi among patients with suspected enteric fever, with resistance patterns assessed at final reporting.
572. Diagnostic accuracy of Widal agglutination testing for enteric fever, using blood culture as reference with sensitivity and specificity assessed during the same acute febrile episode.
573. Association of prior antibiotic use with blood culture negativity in clinically suspected enteric fever, using antibiotic-unexposed patients as comparator and exposure assessed before blood collection.
574. Association of fluoroquinolone nonsusceptibility with prolonged fever among culture-confirmed enteric fever patients, using susceptible isolates as comparator and fever duration assessed during admission.
575. Three-year trend of Salmonella Typhi and Salmonella Paratyphi antimicrobial susceptibility, using routine blood culture records with annual resistance proportions compared by calendar year.

Central Nervous System Infections

Bacterial Meningitis

576. Microbiological profile and antimicrobial susceptibility of bacterial meningitis among patients with cerebrospinal fluid submitted for culture, with pathogen distribution assessed at final laboratory reporting.
577. Diagnostic accuracy of cerebrospinal fluid Gram staining for bacterial meningitis, using culture as reference with sensitivity and specificity assessed during the index admission.
578. Association of prior antibiotic exposure with cerebrospinal fluid culture negativity in suspected bacterial meningitis, using antibiotic-unexposed patients as comparator and exposure assessed before lumbar puncture.
579. Association of bacterial meningitis culture positivity with cerebrospinal fluid cellular and biochemical parameters, using culture-negative meningitis as comparator and values obtained from the same specimen.

Viral Meningitis

580. Diagnostic yield of routine molecular testing for viral meningitis among patients with cerebrospinal fluid pleocytosis, using final clinical diagnosis as comparator with virus-specific detection assessed during admission.
581. Association of viral molecular positivity with cerebrospinal fluid lymphocytic predominance, using test-negative meningitis as comparator and cell counts obtained from the same specimen.
582. Comparative cerebrospinal fluid profiles of laboratory-confirmed viral and bacterial meningitis, using routine microbiological diagnosis with cellular and biochemical parameters assessed at presentation.

Encephalitis

583. Diagnostic yield of routine viral testing among patients with acute encephalitis syndrome, using final clinical diagnosis as comparator with pathogen-specific positivity assessed during hospitalisation.
584. Seroprevalence of Japanese encephalitis virus immunoglobulin M among acute encephalitis syndrome patients where routinely tested, with clinical outcome assessed at discharge.
585. Diagnostic yield of herpes simplex virus molecular testing in cerebrospinal fluid from suspected encephalitis, using final clinical diagnosis as comparator with positivity assessed during admission.
586. Association of laboratory-confirmed encephalitis aetiology with intensive care unit admission, using etiologically unconfirmed encephalitis as comparator and outcome assessed during hospitalisation.

Tuberculous Meningitis

587. Diagnostic accuracy of cartridge based nucleic acid amplification testing in cerebrospinal fluid for tuberculous meningitis, using composite clinical diagnosis as reference with sensitivity assessed during the index admission.
588. Diagnostic yield of mycobacterial culture in suspected tuberculous meningitis, using composite diagnosis as comparator with additional confirmation assessed at final culture reporting.
589. Association of cerebrospinal fluid molecular positivity with disease stage in tuberculous meningitis, using routine clinical staging and laboratory results obtained during the same admission.
590. Comparative cerebrospinal fluid profiles of tuberculous and bacterial meningitis, using microbiologically or clinically confirmed cases with cellular and biochemical parameters assessed at presentation.

Fungal Meningitis

591. Diagnostic accuracy of cryptococcal antigen testing for cryptococcal meningitis, using culture or composite diagnosis as reference with sensitivity and specificity assessed during admission.
592. Agreement between India ink microscopy and cryptococcal antigen testing in cerebrospinal fluid, using culture as reference where available with concordance assessed during the same episode.
593. Association of cryptococcal meningitis with low CD4-positive T-lymphocyte count among adults with human immunodeficiency virus infection, using other central nervous system infections as comparator.

Parasitic CNS Infections

594. Serological profile of suspected cerebral toxoplasmosis among adults with human immunodeficiency virus infection, using imaging and clinical diagnosis as comparator with antibody status assessed during admission.
595. Association of cerebral toxoplasmosis with CD4-positive T-lymphocyte count among human immunodeficiency virus-infected adults, using other central nervous system opportunistic infections as comparator.
596. Diagnostic yield of routine parasitological and serological tests in suspected central nervous system parasitic infections, using final clinical diagnosis as comparator with positivity assessed during admission.

CSF Microbiology

597. Diagnostic yield of cerebrospinal fluid microscopy, bacterial culture, fungal tests, and molecular assays in suspected central nervous system infection, with incremental detection assessed during the index admission.
598. Association of cerebrospinal fluid transport delay with bacterial culture positivity, using promptly processed specimens as comparator and final culture outcome assessed prospectively.
599. Audit of cerebrospinal fluid specimen volume and test allocation in suspected meningitis, using laboratory recommendations as reference with adequacy and diagnostic yield assessed over six months.
600. Turnaround time comparison of cerebrospinal fluid microscopy, culture, antigen testing, and molecular diagnostics, measuring time from specimen receipt to verified result prospectively.

Skin, Soft-Tissue and Wound Infections

Pyogenic Wound Infections

601. Microbiological profile and antimicrobial susceptibility of pyogenic wound infections, using routine aerobic culture with organism distribution and resistance proportions assessed at final laboratory reporting.
602. Association of polymicrobial growth with chronicity of pyogenic wound infection, using monomicrobial infections as comparator and wound duration documented at specimen collection.
603. Prevalence of methicillin-resistant Staphylococcus aureus among pyogenic wound isolates, using cefoxitin disc diffusion with multidrug resistance patterns assessed at final reporting.
604. Prevalence of carbapenem-resistant Gram-negative bacilli in pyogenic wound infections, using routine susceptibility testing with species-specific resistance assessed at final reporting.
605. Association of biofilm formation with multidrug resistance among major pyogenic wound isolates, using microtitre plate assay and routine susceptibility testing assessed after isolate characterization.

Surgical Wound Infections

606. Microbiological profile of surgical wound infections, using routine culture with organism distribution and antimicrobial susceptibility assessed at final reporting: a prospective hospital-based study.
607. Association of diabetes mellitus with multidrug-resistant surgical wound infection, using non-diabetic infected patients as comparator and resistance assessed at final laboratory reporting.
608. Association of preoperative hospitalisation duration with resistant surgical wound infection, using susceptible infections as comparator and hospital days before surgery assessed from records.
609. Association of biofilm-forming Staphylococcus aureus with surgical wound infection, using non-surgical wound isolates as comparator and biofilm strength assessed by microtitre plate assay.
610. Association of multidrug-resistant surgical wound infection with prolonged postoperative stay, using susceptible infections as comparator and duration measured until discharge.

Diabetic Foot Infections

611. Microbiological profile and antimicrobial susceptibility of diabetic foot infections, using deep tissue or clinically indicated wound cultures with organism distribution assessed at final reporting.
612. Association of diabetic foot ulcer severity with polymicrobial infection, using standardized ulcer grading and culture results obtained during the same clinical episode.
613. Association of poor glycaemic control with multidrug-resistant diabetic foot infection, using patients with controlled diabetes as comparator and glycated haemoglobin assessed within three months.
614. Prevalence of methicillin-resistant Staphylococcus aureus and resistant Gram-negative bacilli in diabetic foot infections, using routine susceptibility testing with resistance proportions assessed at final reporting.
615. Association of biofilm formation with chronic diabetic foot infection, using microtitre plate assay and shorter-duration infections as comparator with wound duration recorded at specimen collection.

Burn Wound Infections

616. Microbiological profile and antimicrobial susceptibility of burn wound infections, using routine wound culture with organism distribution and resistance proportions assessed during hospitalisation.
617. Association of burn surface area with multidrug-resistant wound infection, using smaller burn area as comparator and infection status assessed during the same admission.
618. Association of prolonged hospitalisation with carbapenem-resistant burn wound infection, using susceptible infection as comparator and pre-culture hospital days assessed prospectively.
619. Prevalence of Pseudomonas aeruginosa and Acinetobacter baumannii in burn wound infections, using routine culture with susceptibility profiles assessed at final reporting.
620. Association of multidrug-resistant burn wound infection with mortality, using susceptible burn wound infection as comparator and outcome assessed at discharge.

Necrotising Soft-Tissue Infections

621. Microbiological profile of necrotising soft-tissue infections, using clinically obtained deep tissue cultures with monomicrobial and polymicrobial patterns assessed at final reporting.
622. Association of polymicrobial necrotising soft-tissue infection with diabetes mellitus, using monomicrobial infection as comparator and diabetic status documented during admission.
623. Association of multidrug-resistant necrotising soft-tissue infection with mortality, using susceptible infections as comparator and outcome assessed at discharge.
624. Association of blood culture positivity with severe necrotising soft-tissue infection, using blood culture-negative cases as comparator and intensive care requirement assessed during admission.
625. Turnaround time of Gram stain and culture reporting in necrotising soft-tissue infection, measuring time from specimen receipt to preliminary and final microbiological result prospectively.

Chronic Wound Infections

626. Microbiological profile and antimicrobial susceptibility of chronic wound infections, using routine culture with organism distribution and resistance assessed at final reporting.
627. Association of biofilm formation with chronic wound duration, using microtitre plate assay and shorter-duration wounds as comparator with duration recorded at specimen collection.
628. Association of multidrug resistance with recurrent chronic wound infection, using susceptible isolates as comparator and recurrence documented within six months.
629. Association of polymicrobial culture with delayed wound healing, using monomicrobial infection as comparator and healing status assessed within thirty days or at discharge.
630. Comparative bacterial profiles of chronic diabetic and non-diabetic wounds, using routine culture with organism distribution and resistance proportions assessed during the same study period.

Bone and Joint Infections

Osteomyelitis

631. Microbiological profile and antimicrobial susceptibility of culture-confirmed osteomyelitis, using clinically obtained bone or deep tissue specimens with pathogen distribution assessed at final reporting.
632. Association of diabetes mellitus with polymicrobial osteomyelitis, using non-diabetic osteomyelitis as comparator and culture patterns assessed during the index admission.
633. Association of methicillin-resistant Staphylococcus aureus osteomyelitis with prolonged hospitalisation, using methicillin-susceptible infection as comparator and length of stay measured until discharge.
634. Diagnostic yield of bone or deep tissue culture compared with superficial wound swab in osteomyelitis when both are clinically collected, with concordance assessed at final reporting.

Septic Arthritis

635. Microbiological profile and antimicrobial susceptibility of septic arthritis, using clinically obtained synovial fluid culture with organism distribution assessed at final laboratory reporting.
636. Diagnostic accuracy of synovial fluid Gram staining for septic arthritis, using culture as reference with sensitivity and specificity assessed during the index admission.
637. Association of prior antibiotic exposure with culture-negative septic arthritis, using antibiotic-unexposed patients as comparator and exposure assessed before synovial fluid collection.

Prosthetic Joint Infections

638. Microbiological profile of prosthetic joint infection, using clinically obtained tissue and fluid cultures with organism distribution and antimicrobial susceptibility assessed at final reporting.
639. Association of biofilm-producing staphylococci with prosthetic joint infection, using non-prosthetic orthopaedic infections as comparator and biofilm strength assessed by microtitre plate assay.
640. Diagnostic yield of multiple intraoperative specimens in prosthetic joint infection, using cumulative culture positivity as reference with incremental yield assessed during the same operation.

Tuberculous Osteomyelitis

641. Diagnostic yield of cartridge based nucleic acid amplification testing in clinically obtained bone and joint specimens for tuberculous osteomyelitis, using culture or composite diagnosis as reference.
642. Agreement between molecular testing and mycobacterial culture for osteoarticular tuberculosis, using paired clinical specimens with concordance assessed at final culture reporting.
643. Association of prior antitubercular treatment with microbiological positivity in suspected osteoarticular tuberculosis, using treatment-naive cases as comparator and results assessed during the diagnostic episode.
644. Retrospective distribution of osteoarticular tuberculosis by anatomical site and microbiological method, using laboratory records with diagnostic yield assessed over three years.

Implant-Associated Infection

645. Microbiological profile of orthopaedic implant-associated infections, using clinically obtained deep tissue cultures with organism distribution and antimicrobial susceptibility assessed at final reporting.
646. Association of biofilm formation with implant-associated Staphylococcus aureus infection, using non-implant orthopaedic infections as comparator and biofilm strength assessed after isolate characterization.
647. Association of multidrug resistance with orthopaedic implant-associated infection, using susceptible orthopaedic infections as comparator and resistance assessed at final reporting.

Biofilm-Related Infection

648. Association of strong biofilm formation with chronicity of bone and joint infection, using microtitre plate assay and acute infections as comparator with symptom duration recorded at diagnosis.
649. Association of biofilm formation with methicillin resistance among staphylococci from orthopaedic infections, using microtitre plate assay and cefoxitin susceptibility assessed concurrently.
650. Association of strong biofilm formation with recurrent orthopaedic infection, using weak or non-biofilm-producing isolates as comparator and recurrence documented within six months.

Sexually Transmitted Infections

Syphilis

651. Seroprevalence of syphilis among patients attending sexually transmitted infection services, using the routine screening and confirmatory algorithm with demographic distribution assessed at the same visit.
652. Agreement between nontreponemal screening and treponemal confirmatory testing for syphilis, with discordant results classified according to the routine diagnostic algorithm during the same episode.
653. Association of syphilis seropositivity with human immunodeficiency virus infection, using syphilis-seronegative attendees as comparator and human immunodeficiency virus status assessed during the same visit.

Gonorrhoea

654. Prevalence and antimicrobial susceptibility of Neisseria gonorrhoeae among symptomatic patients, using routine culture and susceptibility testing with resistance patterns assessed at final reporting.
655. Diagnostic accuracy of urethral Gram staining for gonorrhoea in symptomatic men, using culture or nucleic acid amplification testing as reference with sensitivity assessed during the same visit.
656. Association of prior antibiotic exposure with culture-negative suspected gonorrhoea, using antibiotic-unexposed patients as comparator and exposure assessed during the preceding thirty days.

Chlamydial Infections

657. Prevalence of Chlamydia trachomatis infection among symptomatic reproductive-age women, using routinely available nucleic acid amplification testing with age and clinical presentation assessed at the same visit.
658. Association of Chlamydia trachomatis positivity with cervicitis, using test-negative symptomatic women as comparator and clinical findings assessed during the same examination.
659. Prevalence of Chlamydia trachomatis coinfection among patients with laboratory-confirmed gonorrhoea where routine molecular testing is available, with coinfection assessed during the same episode.

Trichomoniasis

660. Prevalence of Trichomonas vaginalis among women with vaginal discharge, using wet mount microscopy or routinely available rapid testing with clinical characteristics assessed at the same visit.
661. Diagnostic accuracy of wet mount microscopy for Trichomonas vaginalis, using a routinely available antigen or molecular assay as reference with sensitivity assessed on the same specimen.
662. Association of Trichomonas vaginalis infection with bacterial vaginosis, using parasite-negative symptomatic women as comparator and vaginal microscopy assessed during the same visit.

Genital Herpes

663. Diagnostic yield of molecular testing for herpes simplex virus in clinically suspected genital herpes where routinely available, using clinical diagnosis as comparator with positivity assessed during the same episode.
664. Association of herpes simplex virus positivity with recurrent genital lesions, using test-negative suspected cases as comparator and recurrence history assessed over six months.
665. Serological patterns of herpes simplex virus among patients with recurrent genital ulcer disease where type-specific serology is routinely available, with lesion history assessed at enrollment.

HPV Infection

666. Prevalence of high-risk human papillomavirus among women undergoing cervical screening where molecular testing is routinely available, with cytology findings assessed during the same visit.
667. Association of high-risk human papillomavirus positivity with abnormal cervical cytology, using virus-negative screened women as comparator and cytological category assessed during the same episode.
668. Agreement between high-risk human papillomavirus testing and cervical cytology for identifying women requiring further evaluation, using histopathology where clinically performed as reference.

HIV and STI Coinfection

669. Prevalence of laboratory-confirmed sexually transmitted infections among adults with human immunodeficiency virus infection, using routine diagnostic tests with infection spectrum assessed during the same clinic episode.
670. Association of low CD4-positive T-lymphocyte count with sexually transmitted infection coinfection among adults with human immunodeficiency virus infection, using higher counts as comparator and infections diagnosed during the same period.

Reproductive Tract Infections

Bacterial Vaginosis

671. Diagnostic accuracy of Gram-stain scoring for bacterial vaginosis, using standardized clinical criteria as comparator with sensitivity and specificity assessed during the same gynecological visit.
672. Agreement between Gram-stain scoring and clinical criteria for bacterial vaginosis, with concordance assessed on specimens and examination findings from the same visit.
673. Association of bacterial vaginosis with pregnancy status among symptomatic women, using non-pregnant symptomatic women as comparator and microscopy assessed at the same clinical encounter.
674. Association of recurrent bacterial vaginosis with recent antibiotic exposure, using first-episode bacterial vaginosis as comparator and exposure assessed during the preceding ninety days.

Vulvovaginal Candidiasis

675. Species distribution of Candida from women with vulvovaginal candidiasis, using fungal culture with antifungal susceptibility assessed at final laboratory reporting.
676. Association of diabetes mellitus with culture-confirmed vulvovaginal candidiasis, using culture-negative symptomatic women as comparator and diabetic status assessed during the same episode.
677. Association of recurrent vulvovaginal candidiasis with non-albicans Candida, using first-episode culture-confirmed cases as comparator and recurrence documented within six months.
678. Association of prior antifungal use with fluconazole resistance among vaginal Candida isolates, using susceptible isolates as comparator and exposure assessed during the preceding ninety days.

Pelvic Inflammatory Disease

679. Microbiological profile of clinically diagnosed pelvic inflammatory disease using routinely collected cervical specimens, with organism detection and clinical severity assessed during the same admission.
680. Association of Chlamydia trachomatis or Neisseria gonorrhoeae positivity with pelvic inflammatory disease severity, using test-negative cases as comparator and severity assessed at presentation.
681. Association of prior sexually transmitted infection with recurrent pelvic inflammatory disease, using first-episode cases as comparator and previous infection documented from records.

Cervicitis

682. Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among women with cervicitis, using routine molecular or culture methods with organism distribution assessed during the same visit.
683. Association of mucopurulent cervicitis with Chlamydia trachomatis positivity, using women without this finding as comparator and laboratory testing performed during the same encounter.
684. Diagnostic yield of routine microbiological testing in symptomatic cervicitis, using final clinical diagnosis as comparator with pathogen-specific positivity assessed during the same episode.

Pregnancy-Associated Infections

685. Microbiological profile of symptomatic reproductive tract infections during pregnancy, using routine vaginal and cervical testing with organism distribution assessed during the antenatal episode.
686. Association of bacterial vaginosis with adverse obstetric history among pregnant women, using women without bacterial vaginosis as comparator and previous pregnancy outcomes recorded at enrollment.
687. Association of vaginal Candida colonization with diabetes in pregnancy, using culture-negative pregnant women as comparator and glycaemic status assessed during the same antenatal period.

Infertility-Associated Infections

688. Prevalence of Chlamydia trachomatis antibodies among women evaluated for infertility where serology is routinely available, with tubal-factor infertility status assessed during the same evaluation.
689. Association of Chlamydia trachomatis seropositivity with tubal-factor infertility, using infertility patients without tubal disease as comparator and serology assessed at the same visit.
690. Microbiological profile of clinically indicated genital specimens from couples undergoing infertility evaluation, using routine culture and molecular testing with organism distribution assessed during evaluation.

Neonatal and Paediatric Infections

Neonatal Sepsis

691. Microbiological profile and antimicrobial susceptibility of early-onset neonatal sepsis, using automated blood culture with pathogen distribution and resistance assessed during the index admission.
692. Microbiological profile and antimicrobial susceptibility of late-onset neonatal sepsis, using automated blood culture with pathogen distribution and resistance assessed during the index admission.
693. Association of prematurity with culture-confirmed neonatal sepsis, using term neonates evaluated for sepsis as comparator and infection status assessed during hospitalisation.
694. Association of low birth weight with multidrug-resistant neonatal sepsis, using neonates with susceptible infections as comparator and birth weight recorded at admission.
695. Association of central-line exposure with late-onset neonatal sepsis, using non-infected hospitalised neonates as comparator and device exposure assessed before culture positivity.
696. Association of multidrug-resistant Gram-negative neonatal sepsis with mortality, using susceptible Gram-negative sepsis as comparator and outcome assessed at discharge.

Neonatal Meningitis

697. Microbiological profile of neonatal meningitis, using cerebrospinal fluid microscopy and culture with pathogen distribution and antimicrobial susceptibility assessed during the same admission.
698. Diagnostic accuracy of cerebrospinal fluid Gram staining for neonatal bacterial meningitis, using culture as reference with sensitivity assessed at final microbiology reporting.
699. Association of bloodstream infection with neonatal meningitis, using culture-confirmed neonatal sepsis without meningitis as comparator and cerebrospinal fluid findings assessed during admission.
700. Association of neonatal meningitis with mortality, using neonatal sepsis without meningitis as comparator and outcome assessed at discharge.

Congenital Infections

701. Serological profile of routinely tested congenital infections among pregnant women and neonates with clinical indications, using standard immunoassays with maternal-neonatal concordance assessed at diagnosis.
702. Association of maternal cytomegalovirus serological findings with neonatal clinical abnormalities where routinely evaluated, using unaffected neonates as comparator and findings assessed at birth.
703. Association of maternal Toxoplasma gondii serology with adverse neonatal outcomes, using seronegative mothers as comparator and neonatal status assessed at birth or discharge.
704. Retrospective spectrum of laboratory-confirmed congenital infections in a teaching hospital, using microbiology records with pathogen distribution and neonatal outcomes assessed over three years.

Paediatric Respiratory Infections

705. Microbiological profile of acute lower respiratory infection among hospitalised children, using routine bacterial and viral diagnostics with pathogen distribution assessed during the index admission.
706. Prevalence of respiratory syncytial virus among children hospitalised with bronchiolitis or pneumonia, using routine antigen or molecular testing with age-specific positivity assessed during admission.
707. Association of respiratory syncytial virus positivity with oxygen requirement, using virus-negative lower respiratory infection as comparator and respiratory support assessed during hospitalisation.
708. Association of bacterial culture positivity with severe paediatric pneumonia, using culture-negative pneumonia as comparator and severity assessed at presentation.
709. Seasonal distribution of major paediatric respiratory viruses, using routine laboratory records with monthly positivity assessed over two years.
710. Diagnostic yield of multiplex respiratory viral testing in hospitalised children, using conventional targeted tests as comparator with additional detections assessed during the same illness.

Paediatric Gastrointestinal Infections

711. Prevalence of rotavirus infection among children hospitalised with acute gastroenteritis, using routine stool antigen testing with dehydration severity assessed at admission.
712. Prevalence of intestinal parasites among children with persistent diarrhoea, using direct and concentration microscopy with parasite distribution assessed at final reporting.
713. Association of rotavirus positivity with severe dehydration and length of stay, using rotavirus-negative gastroenteritis as comparator and outcomes assessed during admission.
714. Microbiological profile of bacterial diarrhoea among children, using stool culture with pathogen distribution and antimicrobial susceptibility assessed at final reporting.
715. Comparative clinical profiles of bacterial, viral, and parasitic gastroenteritis in children, using routine laboratory diagnosis with dehydration and hospitalisation duration assessed during admission.

Paediatric Healthcare-Associated Infections

716. Incidence and microbiological profile of healthcare-associated infections in paediatric intensive care units, using standardized surveillance definitions with infection episodes assessed over twelve months.
717. Association of invasive-device exposure with paediatric healthcare-associated infection, using uninfected hospitalised children as comparator and device exposure assessed before infection onset.
718. Association of multidrug-resistant paediatric healthcare-associated infection with mortality, using susceptible infections as comparator and outcome assessed at discharge.
719. Incidence density of central line-associated bloodstream infection in paediatric intensive care units, using standardized definitions with central-line days recorded prospectively.
720. Retrospective three-year surveillance of paediatric healthcare-associated infections and antimicrobial resistance, using infection-control and microbiology records with annual trends compared by calendar year.

Infections in Pregnancy

TORCH Infections

721. Seroprevalence of Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes simplex virus antibodies among pregnant women tested for clinical indications, using routine serology with trimester-specific patterns assessed at testing.
722. Association of selected maternal congenital-infection serological markers with adverse obstetric history, using seronegative pregnant women as comparator and previous pregnancy outcomes assessed at enrollment.
723. Frequency and resolution of equivocal serological results for congenital infections in pregnancy, using repeat testing as comparator with final classification assessed within thirty days.
724. Audit of congenital-infection serology ordering in pregnancy, using clinical indications as reference with test yield and unnecessary testing proportions assessed over twelve months.

Urinary Tract Infections

725. Prevalence and antimicrobial susceptibility of significant bacteriuria among pregnant women, using quantitative urine culture with organism distribution and resistance proportions assessed during pregnancy.
726. Prevalence of asymptomatic bacteriuria among pregnant women, using screening urine culture with trimester distribution assessed at the antenatal visit.
727. Association of diabetes in pregnancy with significant bacteriuria, using culture-negative pregnant women as comparator and glycaemic status assessed during the same antenatal period.
728. Prevalence of extended spectrum beta lactamase-producing Enterobacterales among urinary isolates from pregnant women, using phenotypic confirmatory testing with susceptibility profiles assessed at final reporting.

Group B Streptococcal Infection

729. Prevalence of maternal Group B Streptococcus colonization among pregnant women where screening is routinely practiced, using clinically collected vaginal-rectal swabs with colonization assessed near delivery.
730. Antimicrobial susceptibility of Group B Streptococcus isolates from pregnant women, using routine susceptibility testing with resistance proportions assessed at final laboratory reporting.
731. Association of maternal Group B Streptococcus colonization with selected obstetric risk factors, using non-colonized women as comparator and factors assessed during the same pregnancy.

Hepatitis in Pregnancy

732. Seroprevalence of hepatitis B surface antigen among pregnant women, using routine antenatal screening with trimester and demographic distribution assessed at enrollment.
733. Seroprevalence of hepatitis C virus antibodies among pregnant women, using routine immunoassay with documented transfusion and healthcare exposure assessed at the same visit.
734. Association of hepatitis E virus immunoglobulin M positivity with severe acute hepatitis in pregnancy, using non-hepatitis E acute hepatitis as comparator and clinical outcome assessed during admission.

HIV in Pregnancy

735. Prevalence of human immunodeficiency virus infection among pregnant women undergoing routine antenatal testing, using the national diagnostic algorithm with annual positivity assessed over two years.
736. Association of maternal human immunodeficiency virus viral suppression with antiretroviral treatment duration, using routinely monitored pregnant women and viral load measured during pregnancy.
737. Association of late antenatal human immunodeficiency virus diagnosis with incomplete prevention-of-transmission interventions, using early-diagnosed women as comparator and intervention completion assessed by delivery.

Congenital Transmission

738. Association of maternal hepatitis B surface antigen positivity with neonatal prophylaxis documentation, using antenatal and newborn records with timely prophylaxis assessed within twenty-four hours of birth.
739. Association of maternal human immunodeficiency virus viral suppression with infant infection status, using routine program records with infant testing outcome assessed within six months.
740. Retrospective review of laboratory-confirmed congenital infections and maternal diagnostic findings, using mother-infant records with transmission patterns and neonatal outcome assessed over three years.

Infections in Immunocompromised Patients

HIV-Associated Infections

741. Spectrum of microbiologically confirmed opportunistic infections among adults with human immunodeficiency virus infection, using routine laboratory testing with CD4-positive T-lymphocyte counts assessed within thirty days.
742. Association of CD4-positive T-lymphocyte count below defined thresholds with tuberculosis among adults with human immunodeficiency virus infection, using higher counts as comparator and microbiological diagnosis assessed during the same episode.
743. Association of low CD4-positive T-lymphocyte count with cryptococcal antigen positivity, using higher counts as comparator and antigen testing performed during the same clinical evaluation.
744. Prevalence of intestinal opportunistic parasites among adults with human immunodeficiency virus infection and diarrhoea, using stool microscopy with parasite distribution assessed at final reporting.
745. Retrospective three-year trend of major opportunistic infections among adults with human immunodeficiency virus infection, using microbiology records with annual frequencies compared by calendar year.

Transplant-Associated Infections

746. Spectrum of bacterial, fungal, and viral infections among renal transplant recipients, using routine microbiological diagnostics with infection timing assessed within six months after transplantation.
747. Microbiological profile of urinary tract infection among renal transplant recipients, using quantitative urine culture with antimicrobial resistance assessed at final reporting.
748. Association of immunosuppressive treatment intensity with opportunistic infection among transplant recipients, using patients without infection as comparator and medication exposure assessed before infection onset.
749. Association of cytomegalovirus viral load positivity with symptomatic disease among transplant recipients, using asymptomatic viral detection as comparator and clinical manifestations assessed within thirty days.

Oncology-Associated Infections

750. Spectrum of bloodstream infections among patients with haematological malignancy, using automated blood culture with organism distribution and antimicrobial susceptibility assessed during the index admission.
751. Association of neutropenia with bloodstream infection among chemotherapy patients, using febrile non-neutropenic oncology patients as comparator and culture results assessed during the same episode.
752. Association of prolonged neutropenia with invasive fungal infection, using shorter-duration neutropenia as comparator and fungal diagnosis established during the same admission.
753. Association of central venous catheter exposure with bloodstream infection among oncology patients, using culture-negative febrile patients as comparator and device status assessed before blood culture.
754. Retrospective spectrum of microbiologically confirmed infections among oncology patients, using routine laboratory records with pathogen distribution and mortality assessed over two years.

Neutropenic Sepsis

755. Microbiological profile and antimicrobial susceptibility of bloodstream infection in febrile neutropenia, using automated blood culture with pathogen distribution assessed during the index admission.
756. Association of profound neutropenia with blood culture positivity, using less severe neutropenia as comparator and absolute neutrophil count measured at fever onset.
757. Association of multidrug-resistant Gram-negative bacteraemia with mortality in febrile neutropenia, using susceptible bacteraemia as comparator and outcome assessed at discharge.
758. Association of prior broad-spectrum antibiotic exposure with resistant bloodstream infection in febrile neutropenia, using susceptible infections as comparator and exposure assessed during the preceding ninety days.

Opportunistic Fungal Infections

759. Spectrum of opportunistic fungal infections among immunocompromised patients, using culture, antigen, and routine molecular methods with pathogen distribution assessed during the index admission.
760. Association of prolonged corticosteroid use with invasive fungal infection, using high-risk patients without fungal infection as comparator and exposure assessed during the preceding ninety days.
761. Association of neutropenia with invasive aspergillosis among oncology patients, using non-neutropenic high-risk patients as comparator and fungal diagnosis assessed during admission.
762. Association of diabetes mellitus with mucormycosis among immunocompromised patients, using other invasive fungal infections as comparator and glycaemic status assessed at diagnosis.
763. Association of invasive fungal infection with mortality among immunocompromised patients, using comparable patients without invasive fungal infection as comparator and outcome assessed at discharge.

Opportunistic Viral Infections

764. Association of cytomegalovirus viremia with immunosuppression category among transplant and oncology patients, using routine molecular testing with viral detection assessed during the index episode.
765. Association of cytomegalovirus viral load with symptomatic disease in immunocompromised patients, using asymptomatic viremia as comparator and symptoms assessed within thirty days.
766. Spectrum of routinely detected herpesvirus infections among immunocompromised patients, using molecular or serological diagnostics with pathogen distribution assessed during admission.
767. Association of viral reactivation with lymphopenia among immunocompromised patients, using patients without reactivation as comparator and lymphocyte counts obtained within seven days.

Opportunistic Parasitic Infections

768. Prevalence of Cryptosporidium infection among immunocompromised patients with diarrhoea, using modified acid-fast staining with immune status assessed during the same episode.
769. Association of Strongyloides stercoralis infection with corticosteroid exposure among immunocompromised patients, using parasite-negative patients as comparator and exposure assessed during the preceding ninety days.
770. Spectrum of intestinal parasites among immunocompromised patients with gastrointestinal symptoms, using direct and concentration microscopy with organism distribution assessed at final reporting.

HIV and Opportunistic Infections

HIV Diagnosis

771. Agreement between routinely used rapid human immunodeficiency virus antibody tests within the national diagnostic algorithm, with concordance and indeterminate-result frequency assessed during the same testing episode.
772. Seroprevalence of newly diagnosed human immunodeficiency virus infection among individuals tested at a tertiary hospital, using the national algorithm with annual positivity assessed over two years.
773. Frequency and resolution of discordant human immunodeficiency virus screening results, using repeat algorithmic testing as comparator with final classification assessed within thirty days.
774. Audit of human immunodeficiency virus testing turnaround time from sample collection to verified result, using program benchmarks with compliance assessed over six months.

CD4 Monitoring

775. Association of CD4-positive T-lymphocyte count with opportunistic infection spectrum among adults with human immunodeficiency virus infection, using routine microbiological diagnoses assessed during the same admission.
776. Association of low CD4-positive T-lymphocyte count with tuberculosis coinfection, using higher counts as comparator and microbiological tuberculosis diagnosis assessed within thirty days.
777. Association of CD4-positive T-lymphocyte count with cryptococcal antigen positivity, using routine antigen testing and paired counts obtained within thirty days.
778. Correlation of CD4-positive T-lymphocyte count with absolute lymphocyte count among adults with human immunodeficiency virus infection, using paired measurements obtained during the same clinic visit.

Viral Load

779. Association of human immunodeficiency virus viral load with CD4-positive T-lymphocyte count, using paired routine measurements obtained within thirty days: a retrospective analytical study.
780. Prevalence of virological nonsuppression among adults receiving antiretroviral therapy, using routine viral load testing with treatment duration assessed at the same monitoring episode.
781. Association of treatment interruption with virological nonsuppression, using virologically suppressed patients as comparator and interruption documented during the preceding six months.
782. Association of virological nonsuppression with opportunistic infection, using suppressed patients as comparator and infections diagnosed within six months of viral load testing.

Tuberculosis Coinfection

783. Prevalence of microbiologically confirmed tuberculosis among adults with human immunodeficiency virus infection, using routine tuberculosis diagnostics with CD4-positive T-lymphocyte count assessed within thirty days.
784. Association of low CD4-positive T-lymphocyte count with extrapulmonary tuberculosis among adults with human immunodeficiency virus infection, using pulmonary tuberculosis as comparator.
785. Diagnostic yield of cartridge based nucleic acid amplification testing in human immunodeficiency virus-associated tuberculosis, using mycobacterial culture or composite diagnosis as reference with performance assessed during the index evaluation.
786. Association of tuberculosis coinfection with human immunodeficiency virus virological nonsuppression, using patients without tuberculosis as comparator and viral load assessed within three months.

Fungal Opportunistic Infections

787. Prevalence of cryptococcal antigen positivity among adults with advanced human immunodeficiency virus infection, using routine serum testing with CD4-positive T-lymphocyte count assessed within thirty days.
788. Association of cryptococcal antigen titre with meningitis among adults with human immunodeficiency virus infection, using cerebrospinal fluid evaluation and clinical diagnosis assessed during the same admission.
789. Prevalence of oral candidiasis among adults with human immunodeficiency virus infection, using clinical and routine mycological assessment with CD4-positive T-lymphocyte count assessed at the same visit.
790. Spectrum of culture-confirmed fungal infections among adults with human immunodeficiency virus infection, using routine mycology with organism distribution and outcomes assessed during admission.

Parasitic Opportunistic Infections

791. Prevalence of intestinal parasites among adults with human immunodeficiency virus infection and diarrhoea, using direct, concentration, and modified acid-fast microscopy with species distribution assessed at final reporting.
792. Association of Cryptosporidium infection with low CD4-positive T-lymphocyte count, using parasite-negative diarrhoeal patients as comparator and counts measured within thirty days.
793. Association of intestinal parasitic infection with chronic diarrhoea among adults with human immunodeficiency virus infection, using parasite-negative patients as comparator and symptom duration recorded at testing.
794. Diagnostic yield of repeated stool microscopy in adults with human immunodeficiency virus infection and persistent diarrhoea, using cumulative detection as reference with additional yield assessed within three days.

Viral Coinfections

795. Seroprevalence of hepatitis B virus and hepatitis C virus coinfection among adults with human immunodeficiency virus infection, using routine serology with liver enzyme abnormalities assessed at the same visit.
796. Association of hepatitis B virus coinfection with virological nonsuppression in human immunodeficiency virus infection, using patients without hepatitis B as comparator and viral load assessed during routine monitoring.
797. Association of hepatitis C virus coinfection with elevated liver enzymes among adults with human immunodeficiency virus infection, using hepatitis C-negative patients as comparator and biochemical testing obtained at the same visit.

Antiretroviral Resistance

798. Prevalence of virological failure requiring resistance evaluation among adults receiving antiretroviral therapy, using routine viral load criteria with treatment history assessed at the same monitoring episode.
799. Association of treatment interruption with suspected antiretroviral resistance among patients with persistent virological failure, using continuously treated patients as comparator and interruption assessed over six months.
800. Genotypic resistance patterns among routinely tested human immunodeficiency virus samples with virological failure, using clinical resistance reports with drug-class mutations and treatment history assessed at testing.

Zoonotic Infections

Brucellosis

801. Seroprevalence of brucellosis among patients with prolonged undifferentiated fever, using routine agglutination or immunoassay testing with occupational exposure assessed at presentation.
802. Association of livestock or unpasteurized dairy exposure with brucellosis seropositivity, using seronegative febrile patients as comparator and exposure assessed during the preceding three months.
803. Association of brucellosis seropositivity with hepatosplenomegaly and cytopenias, using seronegative febrile illness as comparator and clinical parameters assessed during the same episode.
804. Seasonal distribution of laboratory-confirmed brucellosis, using routine serology records with monthly positivity proportions assessed over two years.

Leptospirosis

805. Seroprevalence of leptospirosis among patients with acute undifferentiated fever, using immunoglobulin M testing with seasonal distribution assessed over twelve months.
806. Association of leptospirosis seropositivity with acute kidney injury, using seronegative febrile patients as comparator and renal parameters measured during admission.
807. Association of floodwater or occupational exposure with leptospirosis, using seronegative acute febrile illness as comparator and exposure assessed at presentation.
808. Comparative clinical and laboratory profiles of leptospirosis and dengue among laboratory-confirmed patients, using routine diagnostic assays with complications assessed during admission.

Rabies

809. Audit of post-exposure prophylaxis practices among animal-bite patients, using national rabies guidelines with wound care, vaccination, and immunoglobulin appropriateness assessed at presentation.
810. Association of animal-bite category with appropriate rabies immunoglobulin administration, using national recommendations as reference and prophylaxis completion assessed from clinic records.
811. Knowledge and practice regarding rabies post-exposure prophylaxis among healthcare workers, using a structured questionnaire with guideline-concordant responses assessed cross-sectionally.

Scrub Typhus

812. Seroprevalence and seasonal distribution of scrub typhus among acute undifferentiated febrile illness patients, using immunoglobulin M enzyme linked immunosorbent assay with monthly positivity assessed over twelve months.
813. Association of scrub typhus seropositivity with thrombocytopenia and transaminitis, using seronegative febrile illness as comparator and laboratory values measured during admission.
814. Association of scrub typhus with intensive care unit admission, using seronegative acute febrile illness as comparator and outcome assessed during hospitalisation.
815. Diagnostic accuracy of a rapid scrub typhus antibody test against immunoglobulin M enzyme linked immunosorbent assay, with sensitivity and specificity assessed during the same acute febrile episode.
816. Association of delayed scrub typhus diagnosis with organ dysfunction, using earlier-diagnosed cases as comparator and complications assessed during the index admission.

Q Fever

817. Seroprevalence of Coxiella burnetii infection among patients with prolonged undifferentiated fever where testing is routinely available, with animal exposure assessed during the same diagnostic episode.
818. Association of livestock exposure with Coxiella burnetii seropositivity, using seronegative febrile patients as comparator and exposure assessed during the preceding three months.
819. Clinical profile of laboratory-supported Q fever among referred patients, using routine serology with hepatic and haematological abnormalities assessed during the same episode.

Anthrax

820. Retrospective review of clinically suspected anthrax specimens referred for microbiological testing, using laboratory records with specimen type, diagnostic method, and final classification assessed over five years.
821. Audit of biosafety and referral practices for suspected Bacillus anthracis specimens, using institutional and national protocols with compliance assessed over twelve months.
822. Clinical and exposure profile of suspected cutaneous anthrax referrals, using laboratory-confirmed and unconfirmed cases as comparator with livestock exposure assessed at presentation.

Emerging Zoonoses

823. Retrospective laboratory surveillance of emerging zoonotic infections tested at a tertiary hospital, using routine diagnostic records with annual pathogen distribution assessed over three years.
824. Association of animal or occupational exposure with laboratory-confirmed zoonotic infection, using test-negative suspected cases as comparator and exposure assessed at presentation.
825. Audit of specimen referral and turnaround time for suspected emerging zoonotic infections requiring reference laboratory testing, using laboratory timestamps with delays assessed over twelve months.

Vector-Borne Diseases

Malaria

826. Species distribution and seasonal pattern of laboratory-confirmed malaria among febrile patients, using microscopy and rapid antigen testing with monthly positivity assessed over two years.
827. Diagnostic accuracy of rapid malaria antigen testing, using expert peripheral blood smear microscopy as reference with sensitivity and species concordance assessed during acute illness.
828. Association of Plasmodium falciparum infection with severe malaria, using Plasmodium vivax infection as comparator and complications assessed during the index admission.
829. Association of malaria parasite density with thrombocytopenia, using microscopy-confirmed cases and platelet counts obtained during the same acute episode.
830. Three-year trend of malaria positivity and species distribution in a teaching hospital, using routine laboratory records with annual proportions compared by calendar year.

Dengue

831. Seasonal distribution of laboratory-confirmed dengue infection, using non-structural protein one antigen and immunoglobulin M results with monthly positivity proportions assessed over two years.
832. Association of dengue infection with thrombocytopenia severity, using laboratory-confirmed cases and platelet counts obtained during the same acute febrile episode.
833. Diagnostic accuracy of rapid dengue non-structural protein one antigen testing, using enzyme linked immunosorbent assay as reference with performance assessed according to day of illness.
834. Association of laboratory-confirmed dengue with intensive care unit admission, using dengue-negative acute febrile illness as comparator and outcome assessed during hospitalisation.
835. Comparative clinical profiles of non-structural protein one antigen-positive and immunoglobulin M-positive dengue, using illness day and complications assessed during the same admission.

Chikungunya

836. Seroprevalence and seasonal distribution of chikungunya among acute febrile illness patients, using routine immunoglobulin M testing with monthly positivity assessed over twelve months.
837. Association of chikungunya seropositivity with arthralgia severity, using seronegative febrile illness as comparator and symptoms assessed during the same clinical episode.
838. Comparative haematological profiles of laboratory-confirmed chikungunya and dengue, using routine serology with blood counts measured during the same admission.
839. Frequency of dengue and chikungunya coinfection among acute febrile illness patients, using routine serological assays with clinical severity assessed during hospitalisation.

Japanese Encephalitis

840. Seroprevalence of Japanese encephalitis virus immunoglobulin M among patients with acute encephalitis syndrome, using routine cerebrospinal fluid or serum testing with outcome assessed at discharge.
841. Association of Japanese encephalitis laboratory confirmation with neurological outcome, using test-negative acute encephalitis syndrome as comparator and status assessed at discharge.
842. Seasonal distribution of laboratory-confirmed Japanese encephalitis among acute encephalitis syndrome referrals, using routine serology records with monthly positivity assessed over three years.

Scrub Typhus

843. Seroprevalence and seasonal distribution of scrub typhus among acute febrile illness patients, using immunoglobulin M enzyme linked immunosorbent assay with monthly positivity assessed over twelve months.
844. Association of scrub typhus with thrombocytopenia and elevated liver enzymes, using seronegative febrile illness as comparator and laboratory values measured during admission.
845. Association of scrub typhus with severe disease requiring intensive care, using uncomplicated laboratory-confirmed scrub typhus as comparator and outcome assessed during the index admission.
846. Diagnostic accuracy of rapid scrub typhus antibody testing against immunoglobulin M enzyme linked immunosorbent assay, with performance assessed during the same febrile episode.

Filariasis

847. Prevalence of laboratory-confirmed lymphatic filariasis among clinically suspected patients, using nocturnal microscopy or circulating antigen testing with demographic distribution assessed at diagnosis.
848. Agreement between circulating filarial antigen testing and nocturnal blood smear microscopy, using combined diagnosis as reference with concordance assessed within twenty-four hours.

Other Arboviral Diseases

849. Retrospective surveillance of routinely tested arboviral infections beyond dengue and chikungunya, using laboratory records with annual positivity and seasonal distribution assessed over three years.
850. Diagnostic yield of an available arboviral testing panel among acute undifferentiated febrile illness patients, using conventional targeted tests as comparator with additional detections assessed during admission.

Emerging and Re-Emerging Infections

Emerging Viral Diseases

851. Retrospective laboratory surveillance of emerging viral infections tested in a tertiary hospital, using routine molecular and serological records with annual pathogen distribution assessed over three years.
852. Association of travel or exposure history with laboratory-confirmed emerging viral infection, using test-negative suspected cases as comparator and exposure assessed at presentation.
853. Audit of specimen referral and turnaround time for suspected emerging viral diseases requiring reference laboratory testing, using laboratory timestamps with delays assessed over twelve months.

Emerging Bacterial Diseases

854. Retrospective surveillance of uncommon emerging bacterial pathogens isolated from routine clinical specimens, using laboratory records with specimen source and antimicrobial susceptibility assessed over three years.
855. Association of healthcare exposure with newly emerging multidrug-resistant bacterial phenotypes, using susceptible isolates of the same species as comparator and exposure assessed during the preceding ninety days.
856. Audit of identification and referral pathways for unusual bacterial isolates, using laboratory protocols with confirmation rate and turnaround time assessed over twelve months.

Emerging Fungal Diseases

857. Retrospective surveillance of uncommon and emerging fungal isolates in a teaching hospital, using routine mycology records with patient risk factors and specimen distribution assessed over three years.
858. Association of prior antifungal exposure with non-albicans Candida or unusual yeast isolation, using Candida albicans infection as comparator and exposure assessed during the preceding ninety days.
859. Audit of identification and susceptibility testing of unusual yeasts and moulds, using laboratory protocols with completion and referral rates assessed over twelve months.

Zoonotic Spillover

860. Association of recent animal contact with laboratory-confirmed zoonotic infection among patients with undifferentiated fever, using test-negative febrile patients as comparator and exposure assessed at presentation.
861. Retrospective profile of laboratory-confirmed zoonotic infections linked to occupational exposure, using microbiology and clinical records with pathogen distribution assessed over three years.

Outbreak-Associated Infections

862. Retrospective laboratory characterization of hospital infection clusters identified by routine surveillance, using organism, susceptibility pattern, ward, and time overlap with cluster characteristics assessed over three years.
863. Audit of microbiology laboratory response during suspected hospital outbreaks, using institutional outbreak protocols with specimen processing, notification, and turnaround time assessed for each event.

Novel Antimicrobial Resistance

864. Surveillance of newly recognized or unusual antimicrobial resistance phenotypes among routine bacterial isolates, using confirmatory phenotypic testing with organism distribution and frequency assessed over twelve months.
865. Frequency and clinical significance of discordant unusual resistance results requiring confirmatory testing, using repeat reference methods with final resistance classification assessed before report verification.

Molecular Diagnostic Microbiology

Molecular Diagnosis of Bacterial Infections

866. Diagnostic accuracy of routinely available molecular testing for selected bacterial pathogens in sterile body fluids, using conventional culture as reference with sensitivity and additional detection assessed during admission.
867. Diagnostic yield of a multiplex bacterial molecular assay in culture-negative clinically suspected infection, using conventional microbiology as comparator with additional detections assessed during the same episode.
868. Association of prior antibiotic exposure with molecular-positive culture-negative bacterial infection, using concordant molecular and culture-positive cases as comparator and exposure assessed before sampling.
869. Comparative turnaround time of molecular and conventional bacterial diagnostics, measuring time from specimen receipt to verified actionable result prospectively.

Molecular Diagnosis of Tuberculosis

870. Diagnostic accuracy of cartridge based nucleic acid amplification testing for pulmonary tuberculosis, using mycobacterial culture as reference with performance assessed at final culture reporting.
871. Diagnostic accuracy of cartridge based nucleic acid amplification testing for extrapulmonary tuberculosis, using culture or composite diagnosis as reference with specimen-specific sensitivity assessed at final diagnosis.
872. Agreement between cartridge based nucleic acid amplification testing and Truenat molecular testing for Mycobacterium tuberculosis where both are routinely available, with concordance assessed on paired specimens.
873. Agreement between molecular rifampicin resistance detection and line probe assay, using paired Mycobacterium tuberculosis-positive specimens with discordance assessed after final characterization.
874. Frequency and causes of invalid molecular tuberculosis results, using repeat testing as comparator with successful resolution assessed within forty-eight hours.

Molecular Virology

875. Diagnostic agreement between rapid antigen and molecular testing for severe acute respiratory syndrome coronavirus 2, using molecular testing as reference with performance assessed on the same specimen.
876. Diagnostic yield of multiplex respiratory viral molecular testing compared with targeted assays, using hospitalised patients with additional detections assessed during the same respiratory episode.
877. Association of respiratory viral molecular cycle threshold values with clinical severity where routinely reported, using laboratory-confirmed cases with outcome assessed during admission.
878. Comparative turnaround time of molecular and serological testing for selected acute viral infections, measuring time from specimen receipt to verified result prospectively.

Molecular Mycology

879. Diagnostic yield of routinely available fungal molecular testing in culture-negative high-risk patients, using culture or composite diagnosis as comparator with additional detection assessed during admission.
880. Agreement between molecular and conventional identification of selected Candida species where routine molecular testing is available, with species-level concordance assessed after isolate characterization.
881. Comparative turnaround time of molecular and conventional fungal identification in clinically significant isolates, measuring time from isolate availability to verified species result.

Molecular Parasitology

882. Diagnostic accuracy of routinely available molecular testing for selected intestinal protozoa, using concentration microscopy as reference with sensitivity and additional detection assessed on the same stool specimen.
883. Agreement between molecular testing and microscopy for malaria where both are routinely available, with species concordance assessed during the same acute febrile episode.
884. Diagnostic yield of molecular testing in microscopy-negative suspected parasitic infection where routinely available, using final clinical diagnosis as comparator with additional detections assessed during the same episode.

Multiplex Syndromic Panels

885. Diagnostic yield of a multiplex meningitis panel compared with cerebrospinal fluid microscopy and culture, using hospitalised patients with additional pathogen detection assessed during the same admission.
886. Diagnostic yield of a multiplex respiratory panel compared with conventional targeted testing, using hospitalised respiratory illness with additional pathogen detection assessed during the index episode.
887. Frequency and clinical significance of multiple-pathogen detections on multiplex syndromic panels, using conventional testing and case records with final interpretation assessed during hospitalisation.

Resistance Gene Detection

888. Agreement between polymerase chain reaction detection of selected carbapenemase genes and phenotypic carbapenemase testing among carbapenem-resistant Enterobacterales, with genotype-phenotype concordance assessed after isolate characterization.
889. Association of selected resistance genes with carbapenem minimum inhibitory concentration among Klebsiella pneumoniae isolates, using routine molecular testing and broth microdilution assessed concurrently.
890. Agreement between molecular detection of methicillin resistance determinants and cefoxitin disc diffusion among Staphylococcus aureus, with concordance assessed after completion of both methods.

Epidemiology and Molecular Epidemiology

Hospital Outbreaks

891. Retrospective characterization of suspected hospital clusters of carbapenem-resistant Klebsiella pneumoniae, using routine susceptibility patterns and ward-time overlap with cluster characteristics assessed over three years.
892. Laboratory evaluation of suspected intensive care unit clusters of Acinetobacter baumannii, using routine identification and susceptibility profiles with temporal and spatial relatedness assessed during each event.
893. Audit of microbiology laboratory participation in hospital outbreak investigations, using institutional protocols with specimen collection, notification, and reporting timeliness assessed over three years.

Community Outbreaks

894. Retrospective laboratory characterization of community-associated enteric infection clusters, using stool culture and temporal linkage with pathogen distribution assessed over three years.
895. Laboratory profile of community febrile illness clusters referred to a tertiary hospital, using routine serological and molecular tests with aetiological yield assessed during outbreak periods.

Strain Typing

896. Phenotypic strain comparison of carbapenem-resistant Enterobacterales using antibiogram patterns where advanced typing is unavailable, with similarity and ward distribution assessed over twelve months.
897. Comparison of routine phenotypic and available molecular strain-typing results among selected hospital bacterial isolates, with concordance assessed after completion of both methods.

Molecular Fingerprinting

898. Molecular fingerprinting of selected hospital bacterial isolates where a validated routine method is available, with relatedness compared against ward and time overlap during the surveillance period.
899. Agreement between phenotypic antibiogram clustering and routine molecular fingerprinting among selected multidrug-resistant isolates, with concordance assessed after isolate characterization.

Whole-Genome Sequencing

900. Retrospective whole-genome analysis of stored carbapenem-resistant Klebsiella pneumoniae isolates where sequencing is routinely available, with resistance determinants compared with phenotypic susceptibility from the same isolates.
901. Retrospective whole-genome comparison of epidemiologically linked multidrug-resistant bacterial isolates where sequencing is routinely available, with genomic relatedness compared against ward-time overlap.

Transmission Mapping

902. Transmission mapping of multidrug-resistant Gram-negative isolates within intensive care units using routine microbiology and bed-movement data, with temporal-spatial links assessed over twelve months.
903. Mapping of healthcare-associated Staphylococcus aureus bloodstream infections using ward location and admission timelines, with possible transmission links assessed retrospectively over two years.

Phylogenetic Analysis

904. Phylogenetic analysis of routinely sequenced resistant bacterial isolates where sequence data are already generated, with relatedness compared against antimicrobial resistance profiles and specimen sources.
905. Retrospective phylogenetic analysis of routinely generated viral sequences where available, with clustering compared against sampling date and clinical location during the same surveillance period.

Public Health Microbiology

Water Microbiology

906. Microbiological quality assessment of hospital drinking water, using standard bacterial indicator methods with contamination proportions assessed across predefined sampling points over six months.
907. Comparison of bacterial contamination in source, storage, and point-of-use hospital water samples, using standard culture methods with counts assessed on the same sampling days.
908. Association of residual chlorine levels with bacterial contamination in hospital water, using paired chlorine measurement and culture results assessed at each sampling point.
909. Microbiological surveillance of water used in high-risk hospital areas, using routine indicator organisms with monthly contamination patterns assessed over six months.

Food Microbiology

910. Microbiological quality of ready-to-eat food served within a hospital food service, using standard indicator cultures with contamination assessed across scheduled samples over six months.
911. Comparison of bacterial contamination in raw and cooked food samples from hospital kitchens, using standard culture methods with counts assessed on paired sampling days.
912. Association of food-handler hygiene practices with microbial contamination of prepared foods, using observational checklists and culture results assessed during the same sampling period.
913. Microbiological quality of food-contact surfaces in hospital kitchens before and after routine cleaning, using standardized swab cultures with colony-count reduction assessed immediately.

Environmental Microbiology

914. Microbiological profile of high-touch hospital surfaces, using standardized cultures with organism distribution and antimicrobial susceptibility of clinically significant isolates assessed at final reporting.
915. Comparison of environmental bacterial contamination between intensive care and general wards, using identical surface sampling methods with colony counts assessed on the same sampling schedule.
916. Association of cleaning frequency with bacterial surface contamination in high-risk hospital areas, using cleaning records and standardized cultures assessed over six months.

Surveillance of Communicable Diseases

917. Laboratory-based surveillance of dengue, malaria, scrub typhus, and leptospirosis among acute febrile illness patients, using routine diagnostic records with seasonal positivity assessed over two years.
918. Laboratory-based surveillance of enteric fever and bacterial diarrhoeal pathogens, using routine culture records with annual pathogen distribution and resistance patterns assessed over three years.
919. Laboratory-based surveillance of pulmonary tuberculosis and rifampicin resistance, using routine molecular testing records with annual positivity proportions assessed over three years.

Outbreak Investigation

920. Retrospective evaluation of microbiological investigations performed during suspected hospital outbreaks, using outbreak records with diagnostic yield and reporting turnaround time assessed over three years.
921. Association of timely specimen collection with microbiological confirmation during suspected outbreaks, using delayed collection as comparator and diagnostic yield assessed for each event.
922. Audit of outbreak specimen labeling, transport, and laboratory communication, using institutional protocols with compliance assessed across documented outbreak investigations.

Laboratory-Based Surveillance

923. Three-year laboratory surveillance of carbapenem-resistant Enterobacterales, using routine susceptibility records with annual species distribution and resistance proportions compared by calendar year.
924. Three-year laboratory surveillance of methicillin-resistant Staphylococcus aureus, using routine cefoxitin susceptibility records with annual specimen distribution and prevalence compared by calendar year.
925. Three-year laboratory surveillance of major bloodstream pathogens and antimicrobial resistance, using blood culture records with annual pathogen and susceptibility trends assessed by calendar year.

Environmental and Hospital Surveillance Microbiology

Air Sampling

926. Microbiological assessment of air quality in operating theatres using settle-plate sampling, with bacterial colony counts compared before and during routine operating sessions.
927. Comparison of bacterial air counts in intensive care units and general wards, using standardized settle-plate sampling with colony counts assessed during matched time periods.
928. Association of occupancy level with bacterial air counts in selected hospital areas, using standardized air sampling and occupancy records assessed during the same sampling sessions.

Surface Sampling

929. Microbiological surveillance of high-touch surfaces in intensive care units, using standardized swab cultures with bacterial counts and antimicrobial susceptibility of significant isolates assessed at final reporting.
930. Comparison of surface contamination before and after routine cleaning in high-risk wards, using standardized cultures with colony-count reduction assessed immediately after cleaning.
931. Association of surface type with bacterial contamination in hospital wards, using standardized cultures with colony counts compared across predefined surfaces.
932. Surveillance of multidrug-resistant Gram-negative bacilli on intensive care unit surfaces, using routine culture and susceptibility testing with monthly contamination proportions assessed over six months.

Water Surveillance

933. Microbiological surveillance of hospital water outlets for indicator bacteria and clinically significant Gram-negative bacilli, using routine culture with contamination assessed monthly over six months.
934. Association of water storage conditions with bacterial contamination, using storage-site inspection and paired cultures with contamination assessed during the same sampling period.
935. Comparison of bacterial contamination at source and point-of-use hospital water outlets, using standard culture methods with paired results assessed on the same day.

Operation Theatre Surveillance

936. Microbiological surveillance of operating theatre surfaces before and after terminal cleaning, using standardized cultures with colony-count reduction assessed immediately after cleaning.
937. Microbiological assessment of operating theatre air by settle plates before and during surgical activity, with bacterial counts compared across matched sessions.
938. Association of operating theatre traffic with environmental bacterial counts, using door-opening observations and air or surface cultures obtained during the same operating sessions.
939. Audit of operation theatre environmental surveillance practices against institutional policy, with sampling frequency, documentation, and corrective actions assessed over twelve months.

ICU Surveillance

940. Environmental surveillance of intensive care unit high-touch surfaces for multidrug-resistant organisms, using standardized culture and susceptibility testing with monthly contamination assessed over six months.
941. Association of environmental Acinetobacter baumannii contamination with clinical isolation in intensive care unit patients, using temporal and spatial overlap assessed during the same surveillance period.
942. Association of environmental cleaning compliance with multidrug-resistant organism contamination in intensive care units, using direct observation and surface cultures assessed monthly.

High-Risk Area Surveillance

943. Microbiological surveillance of neonatal intensive care unit surfaces, using standardized cultures with organism distribution and antimicrobial susceptibility assessed over six months.
944. Comparison of environmental contamination across neonatal intensive care, adult intensive care, and operating theatre areas, using identical sampling methods with colony counts assessed during matched periods.
945. Audit of corrective actions after positive environmental surveillance cultures in high-risk areas, using institutional protocols with action completion and repeat-culture results assessed within seven days.

Diagnostic Accuracy and Laboratory Evaluation

Conventional Culture versus Rapid Tests

946. Diagnostic accuracy of rapid urine screening for significant bacteriuria, using quantitative urine culture as reference with sensitivity, specificity, and negative predictive value assessed at forty-eight hours.
947. Diagnostic accuracy of rapid malaria antigen testing, using expert peripheral blood smear microscopy as reference with sensitivity and species concordance assessed during acute febrile illness.
948. Diagnostic accuracy of rapid dengue non-structural protein one antigen testing, using enzyme linked immunosorbent assay as reference with performance assessed according to day of illness.
949. Diagnostic accuracy of cryptococcal antigen lateral-flow testing, using fungal culture or composite diagnosis as reference with sensitivity and specificity assessed during the index admission.
950. Diagnostic accuracy of rapid hepatitis B surface antigen testing, using laboratory immunoassay as reference with sensitivity and specificity assessed on the same serum specimens.

Microscopy versus Molecular Methods

951. Diagnostic accuracy of sputum smear microscopy for pulmonary tuberculosis, using cartridge based nucleic acid amplification testing as comparator with sensitivity and concordance assessed on the same specimen.
952. Agreement between acid-fast smear grade and molecular semiquantitative category in pulmonary tuberculosis, using paired sputum results with correlation assessed during the initial diagnostic episode.
953. Diagnostic accuracy of cerebrospinal fluid microscopy for tuberculous meningitis, using molecular testing or composite diagnosis as reference with performance assessed during admission.
954. Agreement between malaria microscopy and routinely available molecular testing where performed, with species-level concordance assessed during the same acute febrile episode.

Serology versus Molecular Tests

955. Agreement between dengue serology and routinely available molecular testing in acute febrile illness, with concordance assessed according to day of illness during the same episode.
956. Diagnostic agreement between hepatitis C virus antibody screening and molecular confirmation, with positive predictive value assessed among reactive serum samples during the same evaluation.
957. Agreement between cytomegalovirus serology and viral-load testing in selected immunocompromised patients, with concordance and clinical disease status assessed during the same episode.
958. Diagnostic agreement between Mycoplasma pneumoniae serology and molecular respiratory testing where both are routinely performed, with concordance assessed during the same acute illness.

Phenotypic versus Genotypic Resistance Testing

959. Agreement between phenotypic carbapenemase testing and polymerase chain reaction detection of common carbapenemase genes in Enterobacterales, with genotype-phenotype concordance assessed after isolate characterization.
960. Agreement between cefoxitin disc diffusion and molecular detection of methicillin resistance determinants among Staphylococcus aureus, with sensitivity and specificity assessed after completion of both methods.
961. Agreement between phenotypic extended spectrum beta lactamase testing and molecular detection of selected beta-lactamase genes among Escherichia coli, with concordance assessed after isolate characterization.
962. Agreement between phenotypic vancomycin resistance and molecular detection of selected resistance genes among Enterococcus species, with concordance assessed after completion of both methods.

Automated versus Conventional Identification

963. Agreement between automated and conventional biochemical identification of Enterobacterales, with species-level concordance and turnaround time assessed at final laboratory reporting: a method-comparison study.
964. Agreement between automated and conventional identification of non-fermenting Gram-negative bacilli, with species-level concordance and discordant isolates reassessed before final reporting.
965. Agreement between automated and conventional identification of Gram-positive cocci, with species-level concordance and turnaround time assessed during routine laboratory processing.
966. Frequency and causes of discordant automated bacterial identification, using repeat conventional identification as comparator with final species assignment assessed within forty-eight hours.

Screening versus Confirmatory Tests

967. Diagnostic performance of cefoxitin disc screening for AmpC beta lactamase production among Enterobacterales, using phenotypic confirmatory testing as reference with sensitivity assessed after overnight incubation.
968. Diagnostic performance of meropenem disc screening for carbapenemase production among Enterobacterales, using modified carbapenem inactivation testing as reference with sensitivity and specificity assessed after incubation.
969. Diagnostic performance of hepatitis C virus antibody screening, using routinely available molecular confirmation as reference with positive predictive value assessed among reactive samples.
970. Diagnostic performance of initial tuberculosis molecular screening for rifampicin resistance, using line probe assay or phenotypic susceptibility as reference with concordance assessed after final characterization.

Laboratory Quality Management

Internal Quality Control

971. Audit of internal quality-control performance for bacterial culture media, using standard control strains and departmental acceptance criteria with failure frequency assessed over six months.
972. Audit of antimicrobial susceptibility quality-control results, using standard reference strains and current acceptable zone ranges with out-of-range events assessed over six months.
973. Association of reagent lot changes with internal quality-control deviations in routine serology, using control values and failure events assessed during the same twelve-month period.
974. Audit of daily temperature-control records for incubators, refrigerators, and freezers, using laboratory acceptance limits with deviations and corrective actions assessed over six months.

External Quality Assurance

975. External quality-assurance performance in bacteriology over multiple proficiency-testing cycles, using provider-assigned results as reference with error categories and corrective actions assessed over two years.
976. External quality-assurance performance in infectious disease serology, using proficiency-testing results with discordance frequency and corrective-action completion assessed across available cycles.
977. Association of recurrent external quality-assurance errors with test category and workflow stage, using proficiency records with error patterns assessed over two years.
978. Audit of corrective actions after external quality-assurance discordance, using laboratory quality procedures with documentation and closure assessed within prescribed timelines.

Pre-Analytical Errors

979. Frequency and types of specimen rejection in a teaching hospital microbiology laboratory, using predefined acceptance criteria with rejection rates categorized by specimen type over six months.
980. Association of transport delay with compromised specimen quality in urine, sputum, and sterile body fluid samples, using laboratory timestamps and acceptance criteria assessed prospectively.
981. Association of improper specimen labeling with laboratory processing delay, using correctly labeled specimens as comparator and turnaround-time difference assessed over six months.
982. Audit of blood culture bottle fill volume and labeling accuracy, using manufacturer and laboratory standards with nonconformity proportions assessed over three months.

Analytical Errors

983. Frequency and causes of repeat bacterial identification testing due to analytical discrepancies, using final verified identification as reference with error categories assessed over six months.
984. Frequency and causes of repeat antimicrobial susceptibility testing, using final verified results as reference with clinically significant categorical changes assessed over six months.
985. Audit of culture media performance failures and their effect on clinical testing, using internal quality-control records with affected batches and repeat testing assessed over twelve months.
986. Frequency of invalid or indeterminate molecular diagnostic results, using repeat testing as comparator with final resolution and causes assessed over six months.

Post-Analytical Errors

987. Frequency and causes of amended microbiology reports, using original and corrected verified reports with potential clinical significance and time to correction assessed over twelve months.
988. Audit of critical microbiology result notification, using institutional notification policy with completeness and time from verification to clinician communication assessed over six months.
989. Frequency of transcription or interpretation errors in manual microbiology reporting, using final authorized reports as reference with error categories assessed over six months.
990. Audit of antimicrobial susceptibility comments and interpretive reporting, using departmental standards with completeness and appropriateness assessed over six months.

Laboratory Turnaround Time

991. Turnaround time for blood culture Gram stain, identification, and susceptibility reporting, using laboratory timestamps with compliance against predefined benchmarks assessed prospectively over six months.
992. Turnaround time for urine culture identification and susceptibility reporting, using laboratory timestamps with delays categorized by pre-analytical, analytical, and post-analytical stages.
993. Turnaround time comparison of conventional and rapid tuberculosis diagnostics, measuring time from specimen receipt to verified result with benchmark compliance assessed prospectively.
994. Association of laboratory workload with microbiology report turnaround time, using daily specimen counts and verified report timestamps assessed over six months.

Biosafety

995. Compliance with biosafety practices among microbiology laboratory personnel, using a structured observational checklist against institutional standards with domain-specific compliance assessed over three months.
996. Association of biosafety training with observed laboratory compliance, using recently trained and untrained personnel as comparator with practices assessed during the same surveillance period.
997. Audit of biological spill and exposure incident management in the microbiology laboratory, using institutional biosafety procedures with reporting and corrective-action compliance assessed over two years.

Laboratory Accreditation

998. Gap analysis of microbiology laboratory practices against applicable national laboratory accreditation requirements, using a structured checklist with nonconformities categorized and assessed during a six-month quality review.
999. Audit of document-control compliance in a microbiology laboratory preparing for accreditation, using laboratory quality standards with obsolete-document and authorization errors assessed over six months.
1000. Audit of verification, validation, quality-control, and competency records for microbiology tests against laboratory accreditation requirements, with completeness and corrective-action status assessed over six months.