Pulmonary tuberculosis screening in anti-retroviral treated adults living with HIV in Kenya

BackgroundPeople living with HIV (PLHIV) who reside in high tuberculosis burden settings remain at risk for tuberculosis disease despite treatment with anti-retroviral therapy and isoniazid preventive therapy (IPT). The performance of the World Health Organization (WHO) symptom screen for tuberculosis in PLHIV receiving anti-retroviral therapy is sub-optimal and alternative screening strategies are needed.MethodsWe enrolled HIV-positive adults into a prospective study in western Kenya. Individuals who were IPT-naive or had completed IPT>6months prior to enrollment were eligible. We evaluated tuberculosis prevalence overall and by IPT status. We assessed the accuracy of the WHO symptom screen, GeneXpert MTB/RIF (Xpert), and candidate biomarkers including C-reactive protein (CRP), hemoglobin, erythrocyte sedimentation rate (ESR), and monocyte-to-lymphocyte ratio for identifying pulmonary tuberculosis. Some participants were evaluated at 6 months post-enrollment for tuberculosis.ResultsThe study included 383 PLHIV, of whom >99% were on antiretrovirals and 88% had received IPT, completed a median of 1.1years (IQR 0.8-1.55) prior to enrollment. The prevalence of pulmonary tuberculosis at enrollment was 1.3% (n =5, 95% CI 0.4-3.0%): 4.3% (0.5-14.5%) among IPT-naive and 0.9% (0.2-2.6%) among IPT-treated participants. The sensitivity of the WHO symptom screen was 0% (0-52%) and specificity 87% (83-90%). Xpert and candidate biomarkers had poor to moderate sensitivity; the most accurate biomarker was CRP >= 3.3mg/L (sensitivity 80% (28-100) and specificity 72% (67-77)). Six months after enrollment, the incidence rate of pulmonary tuberculosis following IPT completion was 0.84 per 100 person-years (95% CI, 0.31-2.23).ConclusionsIn Kenyan PLHIV treated with IPT, tuberculosis prevalence was low at a median of 1.4years after IPT completion. WHO symptoms screening, Xpert, and candidate biomarkers were insensitive for identifying pulmonary tuberculosis in antiretroviral-treated PLHIV.

Automated summary

In Kenyan PLHIV treated with IPT, tuberculosis prevalence was low at a median of 1.4 years after IPT completion. WHO symptoms screening, Xpert, and candidate biomarkers were insensitive for identifying pulmonary tuberculosis in antiretroviral-treated PLHIV.