Prevalence and Phylogenetic Characterization of Hepatitis C Virus Among Indian Men Who Have Sex With Men: Limited Evidence for Sexual Transmission.

Abstract

Data from high-income countries suggest increasing hepatitis C virus (HCV) prevalence/incidence among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM), but limited data derive from low-and-middle-income countries. We recruited 4994 MSM from 5 states across India using respondent-driven sampling. Logistic regression incorporating respondent-driven sampling weights and machine learning feature selection were used to identify correlates of prevalent HCV, and Bayesian phylogenetic analysis was used to examine genetic clustering. The median age was 25 years, the HIV prevalence was 7.2%, and 49.3% of participants reported recent unprotected anal intercourse. The HCV prevalence was 1.3% (95% confidence interval, 1.0%-1.6%; site range, 0.2%-3.4%) and was 3.1% in HIV-positive versus 1.1% among HIV-negative men. HCV infection was significantly associated with injection drug use (odds ratio, 177.1; 95% confidence interval, 72.7-431.5) and HIV infection (4.34; 1.88-10.05). Machine learning did not uncover any additional epidemiologic signal. Phylogenetic analysis revealed 3 clusters suggestive of linked transmission; each contained ≥1 individual reporting injection drug use. We observed a low HCV prevalence in this large sample of MSM despite a high prevalence of known risk factors, reflecting either the need for a threshold of HCV for sexual transmission and/or variability in sexual practices across settings.