Understanding out-migration among female sex workers in South India

Background: Migrant sex workers are known to be vulnerable to HIV. There is substantial female sex worker (FSW) mobility between the borders of Maharashtra and Karnataka, but little programming emphasis on migrant FSWs in India. We sought to understand the individual/cultural, structural, and contextual determinants of migration among FSWs from Karnataka. Methods: A cross-sectional face-to-face interview of 1,567 FSWs from 142 villages in 3 districts of northern Karnataka, India was conducted from January to June 2008. Villages having 10+ FSWs, a large number of whom were migrant, were selected following mapping of FSWs. Multinomial logistic regression was conducted to identify characteristics associated with migrant (travelled for ≥ 2 weeks outside the district past year) and mobile (travelled for \u3c 2 weeks outside the district past year) FSWs; adjusting for age and district. Results: Compared with nonmigrants, migrant FSWs were more likely to be brothel than street based (Adjusted Odds Ratio (AOR): 5.7; 95% confidence interval: 1.6–20.0), have higher income from sex work (Adjusted Odds Ratio (AOR): 42.2; 12.6–142.1), speak \u3e2 languages (AOR: 5.6; 2.6–12.0), have more clients (AOR_per client: 2.9; 1.2–7.2), and have more sex acts per day (AOR_per sex act: 3.5; 1.3–9.3). Mobile FSWs had higher income from sex work (AOR: 13.2; 3.9–44.6) relative to nonmigrants, but not as strongly as for migrant FSWs. Conclusion: Out-migration of FSWs in Karnataka was strongly tied to sex work characteristics; thus, the structure inherent in sex work should be capitalized on when developing HIV preventive interventions. The important role of FSWs in HIV epidemics, coupled with the potential for rapid spread of HIV with migration, requires the most effective interventions possible for mobile and migrant FSWs