Decline in HIV prevalence among female sex workers in Zimbabwe between 2013 and 2023.

HIV epidemic trends among female sex workers in sub-Saharan Africa are rarely known. We analysed HIV prevalence trends among 10,562 female sex workers aged 18-39 years, recruited through serial cross-sectional respondent-driven sampling surveys in 13 towns and 2 cities in Zimbabwe between 2013 and 2023. HIV prevalence remained stable from 2013 to 2016-2017 but declined significantly from 54.6% in 2016-2017 to 38.9% in 2021-2023 (cluster prevalence mean difference: 15.7%, prevalence ratio: 0.74; 95% CI: 0.68-0.79). This decline cannot be attributed to sampling bias or shifts in the characteristics of the female sex worker population. Mathematical modelling using the HIV Synthesis model and age cohort analysis also suggested lower HIV incidence in later years. While the availability of oral pre-exposure prophylaxis increased, there was little evidence of reduced risk behaviour over time. Increased treatment coverage among the male population likely contributed to the lower HIV incidence among female sex workers.