How much does heterosexual commercial sex contribute to India's HIV epidemic?

Through a search, we identified five models of India's HIV epidemic, all of which articulate the hypothesis that heterosexual commercial sex drives India's HIV epidemic. All five models assume more female sex workers (FSWs) than have been mapped (counted), and more than can be inferred from men's sexual behaviour. With best and highest plausible evidence-based estimates (15-20% of 300,000-700,000 FSWs are HIV-positive; FSWs have 570 client contacts per year; clients use condoms with 60-75% of FSW contacts; and the rate of HIV transmission from FSWs to clients is 0.0011-0.002 per unprotected contact), FSWs and clients account for 2-15% of HIV-infected adults, far less than model-based estimates of 44-68%. Overestimating the contribution of commercial sex to India's HIV epidemic misleads prevention programmes to ignore other risks, and promotes the stigmatizing assumption that HIV infection is a sign of immoral behaviour.