People who inject drugs and men who have sex with men living with HIV in India experience low probability of viral rebound and high levels of persistent viremia during the first 12 months of antiretroviral therapy.

People who inject drugs (PWID) and men who have sex with men (MSM) in India are disproportionately affected by HIV and experience challenges achieving sustained viral suppression. We evaluated probabilities of suppression over time and characteristics associated with persistent viremia and viral rebound among MSM and PWID living with HIV (PLHIV) using 12 months of data collected between 2017-2019 from a cluster-randomized trial across 16 cities in India. To assessprobabilities of suppression, we fit logistic transition models with generalized estimating equations. To assess correlates of persistent viremia and viral rebound, we fit multivariable multilevel logistic regression models. Of 750 PWID, 88% were male and 14% completed high school. Of 850 MSM, 29% completed high school and 54% were married. 46% of PWID and 67% of MSM maintained viral suppression once achieved. Probabilities of viral rebound decreased over time. The probability of newly achieving suppression decreased, from 33%-12% after six months among PWID and 60%-13% among MSM. Among PWID, correlates of persistent viremia included lower education, employment, homelessness, and active injection. Among MSM, hazardous alcohol use was associated with viremia and viral rebound. Treatment engagement and support efforts need to be intensified to encourage PLHIV to achieve life-long suppression.