After a run-in phase for community preparedness and the development of a specific education program on adherence, the investigators plan to recruit 100 HIV-infected FSWs in the TasP component of the project (these women will receive a first-line antiretroviral treatment (ART) regimen as per the Benin guidelines) and 250 HIV-negative FSWs in the PrEP component (these women will receive Truvada®). The recruitment period will last for one year, followed by an additional one year of follow-up, for a total follow-up period varying between 12 and 24 months, depending on when a given woman is recruited in the study. During follow-up visits every three months, the investigators will closely monitor treatment adherence and changes in sexual behaviour, including the use of viral load testing among TasP participants and Truvada® plasma level testing for PrEP participants, as well as detection of prostate-specific antigen (PSA) and Y-chromosome DNA in vaginal fluids in all participants.