Goal: To examine and compare young sex workers’ risk of acquisition of sexually transmitted infections (STIs) with the risk among their older counterparts.
Objective: To evaluate the effect of young age—16–19 years vs. 20 years and older—on risk of incident infection with Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT).
Study Design: A randomized controlled trial of 1,000 sex workers in Madagascar was conducted. STI testing was conducted at baseline, 6, 12, and 18 months.
Results: About 13% of the cohort (n = 134) was composed of young women aged 16–19 years. STI incidence rates in this group over the 18-month study period were high: 51.9/100 woman-years (WY) for GC and 47.4/100 WY for CT compared to 27.4/100 WY and 19.1/100 WY for sex workers over age 20, respectively. In multivariable models, young sex workers were at significantly higher STI risk compared with their older peers: The adjusted risk ratio (aRR) for GC comparing younger to older women was 1.50 (95% confidence interval (CI): 1.20, 1.88); for CT, the aRR was 1.72 (95% CI: 1.35, 2.19) and for GC or CT combined, the aRR was 1.42 (95% CI: 1.22, 1.66).
Conclusions: This exploratory analysis suggests that additional research is warranted to identify effective and acceptable prevention strategies that benefit young women, and interventions already proven effective among adolescents should be given high priority for scale-up.