Intensified tuberculosis case finding using the WHO - symptom screening tool and sputum microscopy versus genexpert among HIV-positive adult outpatients visiting a tertiary hospital in Nairobi County, Kenya
Background: Tuberculosis (TB) is the most common opportunistic infection among HIV-positive individuals. Intensified case finding is crucial for prevention and control of this disease supplemented by prompt diagnosis and treatment.
Objective: To determine the prevalence of TB among HIV-positive adults attending the Comprehensive Care Centre (CCC) of Kenyatta National Hospital, Nairobi County, by use of the World Health Organization (WHO) Pulmonary TB (PTB) symptom screening tool and test comparison of smear microscopy with GeneXpert.
Design: Prospective facility based cross-sectional study
Setting: Comprehensive Care Centre of Kenyatta National Hospital, Nairobi County
Participants: HIV-positive adults attending the Comprehensive Care Centre
Results: Out of 1,003 individuals screened by WHO-PTB tool, 896 (89.3%) reported symptoms, of whom 24.4% (219/896) were enrolled; 68.5% (150/219) were <45 years of age and 53.0% (116/219) were females. A total of 27.9% (61/219) enrolees were diagnosed with TB subsequent to matching test positivity by microscopy combined from 1st and 2nd sputum collections with positivity by GeneXpert; 6.6% (4/61) strains revealed resistance to rifampicin. Smear microscopy from 1st and 2nd sputum collection missed 82.0% (11/61) and 14.8% (52/61) cases, respectively.
Conclusion: We found high TB prevalence among HIV-positive adults. Optimized WHO-PTB symptom screening is important in early presumptive TB diagnosis followed by more sensitive laboratory confirmation by GeneXpert than smear microscopy with assessment of antibiotic resistance patterns. Prompt diagnosis impacts treatment outcomes and consequently, illness-attributable morbidity and mortality.