Performance of clinical screening algorithms for tuberculosis intensified case finding among people living with HIV in Western Kenya

Abstract

Objective: To assess the performance of symptom-based screening for tuberculosis (TB), alone and with chest radiography among people living with HIV (PLHIV), including pregnant women, in Western Kenya. Design: Prospective cohort study Methods: PLHIV from 15 randomly-selected HIV clinics were screened with three clinical algorithms [World Health Organization (WHO), Ministry of Health (MOH), and "Improving Diagnosis of TB in HIV-infected persons" (ID-TB/HIV) study], underwent chest radiography (unless pregnant), and provided two or more sputum specimens for smear microscopy, liquid culture, and Xpert MTB/RIF. Performance of clinical screening was compared to laboratory results, controlling for the complex design of the survey. Results: Overall, 738 (85.6%) of 862 PLHIV enrolled were included in the analysis. Estimated TB prevalence was 11.2% (95% CI, 9.9±12.7). Sensitivity of the three screening algorithms was similar [WHO, 74.1% (95% CI, 64.1±82.2); MOH, 77.5% (95% CI, 68.6±84.5); and IDTB/HIV, 72.5% (95% CI, 60.9±81.7)]. Sensitivity of the WHO algorithm was significantly lower among HIV-infected pregnant women [28.2% (95% CI, 14.9±46.7)] compared to nonpregnant women [78.3% (95% CI, 67.3±86.4)] and men [77.2% (95% CI, 68.3±84.2)]. Chest radiography increased WHO algorithm sensitivity and negative predictive value to 90.9% (95% CI, 86.4±93.9) and 96.1% (95% CI, 94.4±97.3), respectively, among asymptomatic men and non-pregnant women. Conclusions: Clinical screening missed approximately 25% of laboratory-confirmed TB cases among all PLHIV and more than 70% among HIV-infected pregnant women. National HIV programs should evaluate the feasibility of laboratory-based screening for TB, such as a single Xpert MTB/RIF test for all PLHIV, especially pregnant women, at enrollment in HIV services.