Objective To characterize prevalence, incidence and associated correlates of HIV infection among MSM in 12 cities across India. Design Cross-sectional sample using respondent-driven sampling (RDS) from September 2012-June 2013 Methods A total 12,022 MSM (∼1000 per city) were recruited. Participants had to be ≥18 years, self-identify as male and report oral/anal intercourse with a man in the prior year. HIV infection was diagnosed using 3 rapid tests. Cross-sectional HIV incidence was estimated using a multi-assay algorithm. All estimates incorporate RDS-II weights. Results Median age was 25 years, 45.0% self-identified as “panthi” (predominantly penetrative anal intercourse) and 30.6% reported being married to a woman. Weighted HIV prevalence was 7.0% (range: 1.7% to 13.1%). In multivariate analysis, significantly higher odds of HIV infection was observed among those who were older, had lower educational attainment, were practicing purely receptive anal sex or both receptive and penetrative sex and those who were HSV-2 positive. Of 1,147 MSM who tested HIV positive, 53 were identified as recent HIV infections (annualized incidence = 0.87%; range = 0 to 2.2%). In multivariate analysis, injecting drugs in the prior 6 months, syphilis, higher number of male partners and fewer female partners were significantly associated with recent HIV infection. Conclusions We observed a high burden of HIV among MSM in India with tremendous diversity in prevalence, incidence and risk behaviors. In particular, we observed high incidence in areas with relatively low prevalence suggesting emerging epidemics in areas not previously recognized to have high HIV burden.

BackgroundDengue and chikungunya are rapidly expanding viruses transmitted by mosquitoes of the genus Aedes. Few epidemiological studies have examined the extent of transmission of these infections in South India despite an increase in the number of reported cases, and a high suitability for transmission.Methods and findingsWe conducted a household-based seroprevalence survey among 1010 individuals aged 5-40 years living in fifty randomly selected spatial locations in Chennai, Tamil Nadu. Participants were asked to provide a venous blood sample and to complete a brief questionnaire with basic demographic and daily activity information. Previous exposure to dengue and chikungunya was determined using IgG indirect ELISA (Panbio) and IgG ELISA (Novatec), respectively. We used this data to estimate key transmission parameters (force of infection and basic reproductive number) and to explore factors associated with seropositivity. While only 1% of participants reported history of dengue and 20% of chikungunya, we found that 93% (95%CI 89-95%) of participants were seropositive to dengue virus, and 44% (95%CI 37-50%) to chikungunya. Age-specific seroprevalence was consistent with long-tem, endemic circulation of dengue and suggestive of epidemic chikungunya transmission. Seropositivity to dengue and chikungunya were significantly correlated, even after adjusting for individual and household factors. We estimate that 23% of the susceptible population gets infected by dengue each year, corresponding to approximately 228,000 infections. This transmission intensity is significantly higher than that estimated in known hyperendemic settings in Southeast Asia and the Americas.ConclusionsThese results provide unprecedented insight into the very high transmission potential of dengue and chikungunya in Chennai and underscore the need for enhanced surveillance and control methods.

In India, men who have sex with men (MSM) remain hidden because anal intercourse was criminalized and marriage socially required. We characterize HIV/STI prevalence among MSM in Tamil Nadu. Eligible participants were recruited using respondent-driven sampling in eight cities (n = 721). Median age was 28, 34% were married and 40% self-identified as homosexual. Median number of male partners in the prior year was 15; 45% reported any unprotected anal intercourse (UAI). HIV, herpes simplex virus-2 (HSV-2), chronic hepatitis B virus (HBV) and syphilis prevalence were 9, 26, 2 and 8%, respectively; among married men, all were higher: 14, 32, 3 and 11% (p < 0.01 for HIV and HSV-2). Less education, HSV-2, more male partners, UAI and not having a main male partner were associated with HIV prevalence. The high STI and UAI prevalence may lead to a burgeoning HIV epidemic among MSM, reinforcing the need for focused preventive measures incorporating complex circumstances.

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NCT01031745.