Characterizing sexual histories of women before formal sex-work in south India from a cross-sectional survey: implications for HIV/STI prevention.

BACKGROUND: Interventions designed to prevent HIV and STIs in female sex-workers (FSWs) reach women after they formally enter the sex-trade. We aimed to characterize the pattern of sexual behaviour among FSWs from first-sex to when they identify as sex-workers (transition period) in a region with traditional (historically characterized by dedication into sex-work at first-sex) and non-traditional forms of sex-work. METHODS: We conducted a cross-sectional survey of 246 traditional and 765 non-traditional FSWs across three districts in Karnataka, India. We performed univariate and multivariate logistic regression to profile FSWs most likely to engage in a commercial first-sex before identifying as a sex-worker. Sexual life-course patterns were distinguished using univariate and multivariate linear regression based on key events associated with length of transition period. RESULTS: Overall, 266 FSWs experienced a commercial first-sex, of whom 45.9% (95% CI: 38.2,53.7) continued a long-term relationship with the first partner. In adjusted analysis, traditional FSWs were more likely to experience a commercial first-sex (AOR 52.5, 95% CI: 27.4,100.7). The average transition time was 8.8 years (SD 3.9), but there was considerable variability between respondents. Among women who experienced a commercial first-sex, a slower transition was independently associated with non-traditional sex-work, the presence of long-term partnerships during the transition period, and ongoing partnerships at time of entry into sex-work. In the absence of a commercial first-sex, a faster transition was associated with traditional sex-work and the dissolution of long-term partnerships, while a slower transition was associated with the presence of long-term partnerships and widowhood. Only 18.5% (95% CI: 12.7,26.2) and 47.3% (95% CI: 32.7,62.3) of women reported 'always' condom use with their long-term and occasional partners during the transition period, respectively. CONCLUSIONS: FSWs identify as sex-workers several years after becoming sexually active, even when the first-sex is commercial in nature. Long-term partnerships are common after a commercial first-sex, and are associated with a delay in formally entering the sex-trade. The findings call for a better understanding of HIV/STI risk before FSWs identify as sex-workers, and an adaptive programme to reach this period of vulnerability.