Increasing age and duration of sex work among female sex workers in South Africa and implications for HIV incidence estimation: Bayesian evidence synthesis and simulation exercise.

Introduction: In sub-Saharan Africa, accurate estimates of the HIV epidemic in female sex workers are crucial for effective prevention and care strategies. These estimates are typically derived from mathematical models that assume certain demographic and behavioural characteristics like age and duration of sex work to remain constant over time. We reviewed this assumption for female sex workers in South Africa. Methods: We reviewed studies that reported estimates on either the age or the duration of sex work among female sex workers in South Africa. We used Bayesian hierarchical models to synthesize reported estimates and to study time trends. In a simulation exercise, we also investigated the potential impact of the "constant age and sex work duration"-assumption on estimates of HIV incidence. Results: We included 24 different studies, conducted between 1996 and 2019, contributing 42 estimates on female sex worker age and 27 estimates on sex work duration. There was evidence suggesting an increase in both the duration of sex work and the age of female sex workers over time. According to the fitted models, over each decade the expected duration of sex work increased by 55.6% (95%-credible interval [CrI]: 23.5%-93.9%) and the expected age of female sex workers increased by 14.3% (95%-CrI: 9.1%-19.1%). Over the 23-year period, the predicted mean duration of sex work increased from 2.7 years in 1996 to 7.4 years in 2019, while the predicted mean age increased from 26.4 years to 32.3 years. Allowing for these time trends in the simulation exercise resulted in a notable decline in estimated HIV incidence rate among sex workers over time. This decline was significantly more pronounced than when assuming a constant age and duration of sex work. Conclusions: In South Africa, age and duration of sex work in female sex workers increased over time. While this trend might be influenced by factors like expanding community mobilization and improved rights advocacy, the ongoing criminalisation, stigmatisation of sex work and lack of alternative employment opportunities could also be contributing. It is important to account for these changes when estimating HIV indicators in female sex workers.

Human rights violations against sex workers: burden and effect on HIV.

We reviewed evidence from more than 800 studies and reports on the burden and HIV implications of human rights violations against sex workers. Published research documents widespread abuses of human rights perpetrated by both state and non-state actors. Such violations directly and indirectly increase HIV susceptibility, and undermine effective HIV-prevention and intervention efforts. Violations include homicide; physical and sexual violence, from law enforcement, clients, and intimate partners; unlawful arrest and detention; discrimination in accessing health services; and forced HIV testing. Abuses occur across all policy regimes, although most profoundly where sex work is criminalised through punitive law. Protection of sex workers is essential to respect, protect, and meet their human rights, and to improve their health and wellbeing. Research findings affirm the value of rights-based HIV responses for sex workers, and underscore the obligation of states to uphold the rights of this marginalised population.