Objectives: To explore the prevalence of and factors associated with initiation of selling sex as a minor.

Design: Data were drawn from cross-sectional studies of adult female sex workers (FSW) recruited through respondent-driven sampling in Ouagadougou and Bobo-Dioulasso, Burkina Faso.

Methods: FSW completed a questionnaire that included a retrospective question regarding the age at which they started selling sex. Separate multivariate logistic regression analyses were conducted for each city to examine associations with initiation of selling sex as a minor (<18 year old), controlling for current age.

Results: Of study participants, 27.8% (194/698) reported selling sex as a minor, ranging from 24.4% (85/349) in Bobo-Dioulasso to 31.2% (85/349) in Ouagadougou. In Ouagadougou, early initiates were more than twice as likely to report someone ever forced them to have sex [age-adjusted odds ratio (aaOR): 2.54, 95% confidence interval (CI): 1.53 to 4.23]. In Bobo-Dioulasso, those who started as minors were more likely to report someone ever tortured them (aaOR: 2.29, 95% CI: 1.28 to 4.10). In both cities, early initiates were more likely to not use a condom with a client if offered more money (Ouagadougou aaOR: 2.34, 95% CI: 1.23 to 4.47; Bobo-Dioulasso aaOR: 2.37, 95% CI: 1.29 to 4.36). In Ouagadougou, women who had started selling sex at a young age were half as likely to have been tested for HIV more than once ever (aaOR: 0.50, 95% CI: 0.26 to 0.94). In Bobo-Dioulasso, early initiates were less likely to attend HIV-related talks or meetings (aaOR: 0.56, 95% CI: 0.33 to 0.97).

Conclusions: A substantial proportion of FSW in Burkina Faso started selling sex as minors. The findings show that there are heightened vulnerabilities associated with selling sex below age 18 years, including physical and sexual violence, client-related barriers to condom use, and lower access to HIV-related services.