Incidence of tuberculosis in HIV-infected adults on first- and second-line antiretroviral therapy in India

BACKGROUND: Programmatic data on the baseline risk of tuberculosis in people living with HIV (PLHIV) are needed to evaluate long-term effectiveness of the ongoing isoniazid preventive therapy (IPT) roll-out in India. METHODS: We estimated the incidence rate and risk factors of tuberculosis disease in adult PLHIV initiating first- and second-line anti-retroviral therapy (ART) prior to widespread IPT in a public ART center in Pune, India. RESULTS: 4067 participants contributing 5205.7 person-years of follow-up on first-line ART and 871 participants contributing 1031.7 person-years of follow-up on second-line ART were included in the analysis. The incidence rate of tuberculosis was 4.39 cases (95%CI 3.86–5.00) per 100 person-years on first-line ART and 1.64 cases (95%CI 1.01–2.63) per 100 person-years on second-line ART (p < 0.001). After adjusting for competing risks, male sex (aSHR = 1.33, 95%CI 1.02–1.74, p = 0.03), urban residence (aSHR = 1.53, 95%CI 1.13–2.07, p = 0.006) and CD4+ counts < 350 cells/mm(3) (aSHR = 3.06 vs CD4 > 350 cells/mm(3), 95%CI 1.58–5.94, p < 0.001) at ART initiation were associated with higher risk of tuberculosis independent of ART regimen. CONCLUSION: Risk of tuberculosis was lower in PLHIV receiving second-line ART compared to first-line ART. Prioritizing IPT in PLHIV with low CD4+ counts, urban residence and in males may further mitigate the risk of tuberculosis during ART.