Enhancing national prevention and treatment services for sex workers in Zimbabwe: a process evaluation of the SAPPH-IRe trial

Background: Targeted HIV interventions for female sex workers (FSW) combine biomedical technologies, behavioural interventions, and community mobilization of sex workers with the aim of empowering FSW and improving prevention and treatment outcomes. Understanding how to deliver such interventions most effectively in sub-Saharan Africa is critical to the HIV response. Methods: The SAPPH-IRe randomized controlled trial in Zimbabwe tested an intervention to improve FSW engagement with HIV prevention and care services. SAPPH-IRe was nested within a comprehensive national FSW programme. After two years, results of the trial showed no significant difference between arms in proportion of all FSW with HIV viral load ≥1000 copies/ml. Both arms showed a steep decline in % FSW with HIV viral load ≥1000 copies/ml. Our process evaluation tracked the intervention’s implementation using data from routine programme statistics, qualitative interviews with participants, and respondent driven surveys. Results: The intervention proved feasible to deliver and was highly acceptable to FSW and providers. Intervention clinics saw more FSW for the first time (4082 vs 2754), performed more than twice as many HIV tests (2606 vs 1151) than control site clinics and nearly double the number of women were diagnosed with HIV (1042 vs 546). Community mobilization meetings in intervention sites also attracted higher numbers. We identified some gaps in fidelity of delivery: PrEP implementation took time to engage FSW, routine viral load monitoring was not performed, and the ratio of peer educators to sex workers was lower than intended. During the trial, reaching FSW with HIV testing and treatment became a national priority, leading to numbers increasing at both intervention and control clinics. Throughout Zimbabwe, ART coverage improved and HIV- stigma declined. FSW responded favourably to non-judgmental services and peer-led activities, which were available in all sites. Conclusions: Zimbabwe’s changing HIV policy context, including widespread intensification of targeted services, appeared to contribute to positive improvements across the HIV care continuum for all female sex workers over the course of the SAPPH-IRe trial. More intense community-based interventions for FSW may be needed to make further gains toward HIV epidemic control.