Differentiated Prevention And Care To Reduce The Risk of HIV Acquisition And Transmission Among Female Sex Workers In Zimbabwe: Study Protocol For The ‘AMETHIST’ Cluster Randomised Trial

Abstract

Background: Female sex workers (FSW) in sub-Saharan Africa are disproportionately affected by HIV and are critical to engage in both HIV prevention and care. Here we describe our approach to evaluation of the AMETHIST intervention for FSW, adapted to the African context and set in Zimbabwe where there is a nationally-scaled programme for sex workers (Sisters). We hypothesise this intervention will raise uptake and adherence to prevention and treatment among FSW resulting in a reduction in their risk of HIV acquisition/transmission.Methods: The AMETHIST intervention (Adapted Microplanning to Eliminate Transmission of HIV in Sex Transactions) aims to provide risk differentiated prevention and care to FSW through microplanning and self help groups. Twenty two towns with the Sisters programme were randomised using restricted randomisation to either the Sisters programme or the Sister programme plus AMETHIST. The primary outcome is composite and is defined as the proportion of HIV positive FSW at risk of HIV transmission combined with the proportion of HIV negative FSW at risk of HIV acquisition. The outcome will be assessed after two years of intervention delivery in a respondent-driven sampling survey (total n=4400; n=200 FSW recruited at each site). Primary analysis will use the ‘RDS-2’ method to estimate cluster summaries and will adapt Hayes and Moulton’s ‘2-step’ method to adjust effect estimates for individual-level confounders and further adjust for cluster baseline prevalence. An in-depth process evaluation guided by our project trajectory will be undertaken.Discussion: Innovative pragmatic trials are needed to generate evidence on effectiveness of combination interventions in HIV prevention and treatment in different contexts. We describe the design and analysis of such a study.Trial Registration: The trial was registered at Pan African Clinical Trials Registry (PACTR202007818077777) on 2 July 2020.

Using a Programme Science approach to substantially reduce the risk of HIV transmission and acquisition in sex transactions among female sex workers in Zimbabwe

“…In addition, some clinical indicators also strengthened across sites (number of HIV tests increased from under 500 Jan−Mar 2021 to around 2000 Aug−Sep 2021; number of FSW newly initiated on PrEP increased from under 100 to over 400 over the same period). Rates of FSW newly identified with HIV and initiated on ART remain high throughout [23]. Of note, the optimization exercise was not conducted in the AMETHIST control sites.…”

“…Of note, the optimization exercise was not conducted in the AMETHIST control sites. While control sites saw a rebound in service uptake after SARS‐COV2 lockdowns, this was lower than in AMETHIST sites [23].…”

“…Likely as a result, Zimbabwe has one of the few comprehensive, nationally scaled programmes for sex workers in Africa [26], providing services for around 40,000 FSW annually, while providing a range of insights into programme implementation and its likely impact [32][33][34]. Recent data suggest that engagement of FSW in treatment and care is equal to or exceeds that of the general population of adult women in Zimbabwe, with 93% of FSW living with HIV in the AME-THIST intervention arm of the trial being virally suppressed [23], which is counter to the trend seen in other east and southern African countries [34]. Most recently, a combined analysis of programme, survey and modelling data suggests that HIV incidence among FSW may be declining [35].…”

“…The intervention targeted FSW who lived or worked in the area surrounding the KP programme site. The primary trial findings are reported elsewhere [23].…”