LAUSR

Background The conduction of 3 cohort studies among professional female sex workers (FSWs), e.g. women whose main source of revenue is sex work, since 2008 in Benin allowed the estimation of time trends in HIV, gonorrhea and chlamydia prevalence and incidence in this key population over the last decade. Methods The 3 cohort studies were conducted from 09/2008-03/2012, 10/2014-12/2016 and 04/2017-09/2018, respectively. Women were recruited at the Dispensaire IST, a FSW-dedicated clinic, after providing informed consent. Follow-up was quarterly in the first 2 studies and bi-annual in the latest one. FSWs were tested for HIV (rapid test with confirmatory assay according to Benin guidelines), gonorrhea and chlamydia (BD ProbeTec™ CT/NG, Becton Dickinson Inc.) at baseline and at each follow-up for HIV and semi-annually for gonorrhea and chlamydia. Questionnaires were administered. Results In all studies, median age was 32–33 years and the proportion of women not born in Benin 50–60%. HIV [gonorrhea (chlamydia)] prevalence was 37.1% [4.3% (3.5%)] in 2008 (n=396), 29.1% [9.7% (4.8%)] in 2014 (n=361) and 26.0% [13.8% (7.4%)] in 2017 (n=312). There was a significant downward (upward) trend in HIV (gonorrhea and chlamydia) prevalence: p<0.001 (p<0.001 and p=0.03). Among respectively 319, 299 and 213 women with follow-up, gonorrhea (chlamydia) incidence was 8.9 (2.1), 9.0 (4.6) and 14.8 (5.8) per 100 person-years; p=0.07(p=0.003). HIV incidence was 1.4, 0.8 and 0.7 per 100 person-years in 2008–12, 2014–16 and 2017–18, respectively (p=0.41). Conclusion HIV prevalence is decreasing, but still high, whereas HIV incidence is low in this highly mobile key population. This combination of high prevalence and low incidence is likely due to HIV treatment scale-up over the last decade, including the adoption of an HIV “test and treat” strategy since 2016 in Benin. However, the increase in both gonorrhea and chlamydia is worrying and calls for renewed control strategies for these curable infections. Disclosure No significant relationships.