Long-term protection from TB preventive treatment among people with HIV in a high-burden tuberculosis setting: an observational cohort study from India

Abstract Background Tuberculosis (TB) preventive treatment (TPT) is critical to the end TB strategy. There is limited evidence on its long-term protective effect among people living with HIV (PLWH) receiving antiretroviral therapy (ART) in high-burden programmatic settings. Methods This observational cohort study included PLWH who initiated a single TPT course from March 2017 to September 2018 at 14 ART centres in Andhra Pradesh, India (TB prevalence: 274/100,000). We followed PLWH for 6 years and censored person-time at TB diagnosis, loss to follow-up, or death. We calculated TB incidence rates (IR) and mortality rates (MR) per 100 person-years (PY) stratified by TPT completion and effective ART (viral load<1000 copies/ml). Cox-proportional hazards models estimated adjusted hazard ratios (aHR) with 95% confidence limits (95% CL) for TB and mortality. Findings We followed 4,706 PLWH for 23,414 PY. TB was diagnosed in 135 PLWH (2.9%)—122 among 4,454 PLWH who completed TPT (IR: 0.55/100PY, 95% CL: 0.46–0.66), and 13 among 252 PLWH who did not (IR: 1.06/100PY, 95% CL: 0.56–1.81). There were 553 all-cause deaths (11.8%)—MR: 2.2/100PY (95% CL: 2.0–2.4) among those who completed TPT compared to 13.5/100PY (95% CL: 11.1–16.3) among those who did not. TPT, combined with effective ART, was associated with an 87% reduction in TB (aHR: 0.13; 95% CL: 0.05–0.37) and a 94% reduction in all-cause mortality (aHR: 0.06; 95% CL: 0.04–0.10). Conclusion A single TPT course combined with effective ART conferred durable protection against TB and significantly reduced mortality among PLWH in a high-burden TB setting.