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BackgroundPopulation size estimates (PSEs) for hidden populations at increased risk of HIV, including female sex workers (FSWs), are important to inform public health policy and resource allocation. The service multiplier method (SMM) is commonly used to estimate the sizes of hidden populations. We used this method to obtain PSEs for FSWs at 9 sites in Zimbabwe and explored methods for assessing potential biases that could arise in using this approach. ObjectiveThis study aimed to guide the assessment of biases that arise when estimating the population sizes of hidden populations using the SMM combined with respondent-driven sampling (RDS) surveys. MethodsWe conducted RDS surveys at 9 sites in late 2013, where the Sisters with a Voice program (the program), which collects program visit data of FSWs, was also present. Using the SMM, we obtained PSEs for FSWs at each site by dividing the number of FSWs who attended the program, based on program records, by the RDS-II weighted proportion of FSWs who reported attending this program in the previous 6 months in the RDS surveys. Both the RDS weighting and SMM make a number of assumptions, potentially leading to biases if the assumptions are not met. To test these assumptions, we used convergence and bottleneck plots to assess seed dependence of RDS-II proportion estimates, chi-square tests to assess if there was an association between the characteristics of FSWs and their knowledge of program existence, and logistic regression to compare the characteristics of FSWs attending the program with those recruited to RDS surveys. ResultsThe PSEs ranged from 194 (95% CI 62-325) to 805 (95% CI 456-1142) across 9 sites from May to November 2013. The 95% CIs for the majority of sites were wide. In some sites, the RDS-II proportion of women who reported program use in the RDS surveys may have been influenced by the characteristics of selected seeds, and we also observed bottlenecks in some sites. There was no evidence of association between characteristics of FSWs and knowledge of program existence, and in the majority of sites, there was no evidence that the characteristics of the populations differed between RDS and program data. ConclusionsWe used a series of rigorous methods to explore potential biases in our PSEs. We were able to identify the biases and their potential direction, but we could not determine the ultimate direction of these biases in our PSEs. We have evidence that the PSEs in most sites may be biased and a suggestion that the bias is toward underestimation, and this should be considered if the PSEs are to be used. These tests for bias should be included when undertaking population size estimation using the SMM combined with RDS surveys.

: Introduction: We used a Programme Science platform, to generate evidence to support the implementation of programmes for sex workers in Africa. Female sex workers are estimated to make up 1.6% (1.3%–1.8%) of the population of women aged 15−49 years in Zimbabwe. We highlight how programme science can be used to help distinguish between when, where and with whom programmes need to be implemented and discuss two case studies that exemplify implementing better (Case study 1 (1 June 2019−30 June 2021) Optimizing implementation of a risk differentiated microplanning intervention) and implementing differently (Case study 2 (1 October 2016−30 September 2022) Reorientating implementation of DREAMS for young women selling sex). Methods: Zimbabwe's nationally scaled programme for sex workers was established in 2009 in partnership with sex workers to provide comprehensive services for sex workers and generate evidence for programme design, implementation and scale up. Since inception, comprehensive data have been collected from all sex workers seeking services. As the scope of service provision has expanded so has the scope of data collection and analysis. At enrolment, sex workers are assigned an alphanumeric unique identifier which links consultations within and across programme sites. We conduct descriptive analyses of the Key Population (KP) programme data to guide programme implementation and redesign, embedding programmatic qualitative enquiry as required. Results: Two case studies describing different approaches to programme optimization are presented. In the first, an optimization exercise was used to strengthen programme implementation ensuring that the KP programme got back on track after SARS‐COV‐2. In the second, an in‐depth review of research and programme data led to a re‐orientation of the DREAMS programme to ensure that young women at the highest risk of HIV acquisition were enrolled and had access to DREAMS social support interventions in turn strengthening their uptake of HIV prevention. Conclusions: Optimizing and sustaining HIV care and treatment programmes requires effective delivery with sufficient scale and intensity for population impact. Our programme science approach guided the scale up of the KP programme in Zimbabwe, providing evidence to support strategy, implementation and ongoing management, and importantly helping us distinguish between when we needed to just implement, implement better or implement differently., INTRODUCTION Early in the HIV epidemic, programming and research involving female sex workers (FSW) was central to the African response. In the 2000s, the focus shifted to the general population, [...]

Background Syndromic management is widely used to treat symptomatic sexually transmitted infections in settings without aetiologic diagnostics. However, underlying aetiologies and consequent treatment suitability are uncertain without regular assessment. This systematic review estimated the distribution, trends, and determinants of aetiologies for vaginal discharge, urethral discharge, and genital ulcer in sub-Saharan Africa (SSA). Methods and findings We searched Embase, MEDLINE, Global Health, Web of Science, and grey literature from inception until December 20, 2023, for observational studies reporting aetiologic diagnoses among symptomatic populations in SSA. We adjusted observations for diagnostic test performance, used generalised linear mixed-effects meta-regressions to generate estimates, and critically appraised studies using an adapted Joanna Briggs Institute checklist. Of 4,418 identified records, 206 reports were included from 190 studies in 32 countries conducted between 1969 and 2022. In 2015, estimated primary aetiologies for vaginal discharge were candidiasis (69.4% [95% confidence interval (CI): 44.3% to 86.6%], n = 50), bacterial vaginosis (50.0% [95% CI: 32.3% to 67.8%], n = 39), chlamydia (16.2% [95% CI: 8.6% to 28.5%], n = 50), and trichomoniasis (12.9% [95% CI: 7.7% to 20.7%], n = 80); for urethral discharge were gonorrhoea (77.1% [95% CI: 68.1% to 84.1%], n = 68) and chlamydia (21.9% [95% CI: 15.4% to 30.3%], n = 48); and for genital ulcer were herpes simplex virus type 2 (HSV-2) (48.3% [95% CI: 32.9% to 64.1%], n = 47) and syphilis (9.3% [95% CI: 6.4% to 13.4%], n = 117). Temporal variation was substantial, particularly for genital ulcer where HSV-2 replaced chancroid as the primary cause. Aetiologic distributions for each symptom were largely the same across regions and population strata, despite HIV status and age being significantly associated with several infection diagnoses. Limitations of the review include the absence of studies in 16 of 48 SSA countries, substantial heterogeneity in study observations, and impeded assessment of this variability due to incomplete or inconsistent reporting across studies. Conclusions In our study, syndrome aetiologies in SSA aligned with World Health Organization guidelines without strong evidence of geographic or demographic variation, supporting broad guideline applicability. Temporal changes underscore the importance of regular aetiologic re-assessment for effective syndromic management. PROSPERO number CRD42022348045., Author(s): Julia Michalow 1,*, Magdalene K. Walters 1, Olanrewaju Edun 1, Max Wybrant 1, Bethan Davies 2, Tendesayi Kufa 3, Thabitha Mathega 3, Sungai T. Chabata 4, Frances M. Cowan [...]

Background: Effective strategies to reduce sexually transmitted infection burden and transmission among female sex workers (FSWs) and their networks are needed. We report sexually transmitted infection prevalence among FSWs in Zimbabwe and investigate the performance of screening algorithms. Methods: Respondent-driven sampling (RDS) surveys, including blood sampling for syphilis serology, were conducted among FSWs in 3 communities in Zimbabwe in 2017. In addition, a random sample of one-third of participants were offered genital examination and sexually transmitted infection (STI) testing. Data on symptoms and clinical signs were analyzed to determine the proportion of asymptomatic and clinically inapparent STIs by HIV status, and the sensitivity, specificity, and predictive values of syndromic, clinical, and hybrid screening algorithms for chlamydia and gonorrhea. Analyses were RDS-II weighted. Results: Overall, 2507 women were included in the RDS surveys, and 661 of 836 (79.1%) of those randomly offered genital examination and STI testing accepted. The prevalence of STI by site ranged from 15.7% to 20.0% for syphilis (rapid plasma reagin + Treponema pallidum hemagglutination assay), 6.8% to 14.3% for gonorrhea, 8.4% to 10.1% for chlamydia, 26.6% to 35.5% for trichomonas, and 37.0% to 47.6% for any high-risk human papilloma virus. A high proportion of infections were both asymptomatic and clinically undetectable (gonorrhea: 41.2%, chlamydia: 51.7%, trichomonas: 62.8%). Screening algorithms performed poorly whether based on symptoms only (sensitivity: 53.3% gonorrhea, 43.3% chlamydia) or either symptoms or clinical signs (sensitivity: 58.7% gonorrhea, 48.3% chlamydia). Conclusions: Sexually transmitted infection burden is high among FSWs in Zimbabwe. The low sensitivity and specificity of screening algorithms used to guide syndromic management mean that more effective approaches are required to strengthen STI control. As access to HIV-specific prevention methods like preexposure prophylaxis increases, support for consistent condom use needs to be strengthened. [ABSTRACT FROM AUTHOR]

: Introduction: Early diagnosis of HIV is critical for epidemic control. To achieve this, successful testing programmes are essential and test positivity is often used as a marker of their performance. The aim of this study was to analyse trends and predictors of HIV test positivity over time and explore how an understanding of seroconversion rates could build on our interpretation of this indicator among female sex workers in Zimbabwe. Methods: We analysed HIV test data from Zimbabwe's nationally scaled sex work programme between 2009 and 2019. We defined test positivity as the proportion of all tests that were HIV positive and measured new diagnoses by estimating seroconversion rates among women with repeat tests, defined as an HIV‐positive test after at least one HIV‐negative test in the programme. We used logistic regression to analyse test positivity over three time‐periods: 2009–2013, 2014–2017 and 2018–2019, adjusting for potential confounding by demographic factors and the mediating effects of time since last HIV test. We calculated the seroconversion rates for the same time‐periods. Results: During the 10‐year study period, 54,503 tests were recorded in 39,462 women. Between 2009 and 2013, 18% of tests were among women who reported testing in the previous 6 months. By 2018–2019, this had increased to 57%. Between 2018 and 2019, test positivity was 9.6%, compared to 47.9% for 2009–2013 (aOR 6.08 95% CI 5.52–6.70) and 18.8% for 2014–2017 (aOR 2.17 95% CI 2.06–2.28). Adjusting for time since last test reduced effect estimates for 2009–2013 (aOR 4.03 95% CI 3.64–4.45) and 2014–2017 (aOR 1.97 95% CI 1.86–2.09) compared to 2018–2019. Among 7573 women with an initial HIV‐negative test in the programme and at least one subsequent test, 464 tested HIV positive at a rate of 3.9 per 100 pyar (95% CI 3.5–4.2). Conclusions: Test positivity decreased among women testing through the programme over time, while seroconversion rates remained high. These declines were partly driven by changes in individual testing history, reflecting comprehensive coverage of testing services and greater knowledge of HIV status, but not necessarily declining rates of seroconversion. Understanding testing history and monitoring new HIV infections from repeat tests could strengthen the interpretation of test positivity and provide a better understanding of programme performance., INTRODUCTION Early diagnosis of HIV is critical for epidemic control. Female sex workers (FSW) in sub‐Saharan Africa are at greater risk of HIV infection than other women of reproductive age, [...]

Introduction: Across sub-Saharan Africa, selling sex puts young women at high risk of HIV. Some young women who sell sex (YWSS) may self-identify as sex workers, while others may not, having implications for how to reach them with HIV prevention. We describe characteristics, sexual behaviours and health service use of YWSS in Zimbabwe, comparing women who identified as female sex workers (FSW) and women who did not (non-identifying-YWSS), and explore factors associated with HIV infection. Methods: We analysed data from respondent-driven sampling (RDS) surveys among YWSS aged 18 to 24 implemented in six sites in Zimbabwe from April to July 2017. RDS was used to enrol YWSS into an impact evaluation of the multi-country DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored and Safe) Partnership, which provides comprehensive HIV prevention programming to adolescent girls and young women. Women completed an interviewer-administered questionnaire and were offered HIV testing services. We used logistic regression (RDS-II-weighted, normalized by site) to identify factors associated with prevalent HIV infection. Results: Forty-four seeds recruited 2387 YWSS. RDS-adjusted HIV prevalence was 24%; 67% of women identified as FSW. FSW were older and had lower educational attainment than non-identifying-YWSS. While 40% of FSW reported 10+ clients in the previous month, 9% of non-identifying-YWSS did so. FSW were more likely to have accessed HIV-related services, including HIV testing in the last six months (FSW: 70%; non-identifying-YWSS: 60%). Over half of all YWSS described selling sex as their main financial support (FSW: 88%; non-identifying YWSS: 54%). Increasing age, lower educational attainment, younger age of first selling sex and higher number of clients in the previous month were associated with prevalent HIV. Conclusions: YWSS in Zimbabwe have a high prevalence of HIV, reported high numbers of sexual partners and depend financially on selling sex. Non-identifying-YWSS differed socio-demographically to FSW, yet factors associated with HIV risk were similar for all women. Women not identifying as FSW were less likely to access services, suggesting they should be prioritized for HIV prevention. Network-based recruitment may enhance their inclusion in programmes, like DREAMS, which aim to reach young women at highest-risk with comprehensive health, HIV prevention and social protection services. Keywords: female sex worker; adolescents and young women; HIV infection; HIV prevention; Zimbabwe; Sub-Saharan Africa, 1 | INTRODUCTION In sub-Saharan Africa, adolescent girls and young women aged 15 to 24 are more vulnerable to HIV infection than their male peers and older women [1]. At [...]

: Introduction: Surveillance of recent HIV infections in national testing services has the potential to inform primary prevention programming activities. Focusing on procedures required to accurately determine recent infection, and the potential for recent infection surveillance to inform prevention efforts, we present the results of three independent but linked pilots of recency testing. Methods: To distinguish recently acquired HIV infection from long‐standing infection, in 2018 we applied a Recent Infection Testing Algorithm that combined a laboratory‐based Limiting Antigen Avidity Enzyme Immunoassay with clinical information (viral‐load; history of prior HIV diagnosis; antiretroviral therapy‐exposure). We explored potential misclassification of test results and analysed the characteristics of participants with recent infection. We applied the algorithm in antenatal clinics providing prevention of mother‐to‐child transmission services in Siaya County, Kenya, outreach sites serving female sex workers in Zimbabwe, and routine HIV testing and counselling facilities in Nairobi, Kenya. In Nairobi, we also conducted recency testing among partners of HIV‐positive participants. Results: In Siaya County, 2.3% (10/426) of HIV‐positive pregnant women were classified as recent. A risk factor analysis comparing women testing recent with those testing HIV‐negative found women in their first trimester were significantly more likely to test recent than those in their second or third trimester. In Zimbabwe, 10.5% (33/313) of female sex workers testing HIV‐positive through the outreach programme were classified recent. A risk factor analysis of women testing recent versus those testing HIV‐negative, found no strong evidence of an association with recent infection. In Nairobi, among 532 HIV‐positive women and men, 8.6% (46) were classified recent. Among partners of participants, almost a quarter of those who tested HIV‐positive were classified as recent (23.8%; 5/21). In all three settings, the inclusion of clinical information helped improve the positive predictive value of recent infection testing by removing cases that were likely misclassified. Conclusions: We successfully identified recently acquired infections among persons testing HIV‐positive in routine testing settings and highlight the importance of incorporating additional information to accurately classify recent infection. We identified a number of groups with a significantly higher proportion of recent infection, suggesting recent infection surveillance, when rolled‐out nationally, may help in further targeting primary prevention efforts., INTRODUCTION Knowing where and among whom new HIV infections are occurring is helpful in estimating HIV incidence and also, potentially, in guiding prevention programmes and evaluating their impact [1‐7]. Identifying [...]

: Introduction: Adolescent girls and young women (AGYW), including those who sell sex in sub‐Saharan Africa, are especially vulnerable to HIV. Reaching them with effective prevention is a programmatic priority. The HIV prevention cascade can be used to track intervention coverage, and identify gaps and opportunities for programme strengthening. The aim of this study was to characterise gaps in condom use and identify reasons underlying these gaps among young women who sell sex (YWSS) in Zimbabwe using data from enrolment into an impact evaluation of the DREAMS programme. DREAMS provided a package of biomedical, social and economic interventions to AGYW aged 10 to 24 with the aim of reducing HIV incidence. Methods: In 2017, we recruited YWSS aged 18 to 24 using respondent‐driven sampling in six sites across Zimbabwe. We measured knowledge about efficacy of, access to, and effective (consistent) use of condoms with the most recent three sexual partners, separately by whether YWSS self‐identified as female sex workers (FSW) or not. Among YWSS without knowledge about efficacy of, not having access to, and not effectively using condoms, we described the potential reasons underlying the gaps in the condom cascade. To identify socio‐demographic characteristics associated with effective condom use, we used logistic regression modelling. All analyses were RDS‐II weighted and restricted to YWSS testing HIV‐negative at enrolment. Results: We enrolled 2431 YWSS. Among 1842 (76%) YWSS testing HIV‐negative, 66% (n = 1221) self‐identified as FSW. 89% of HIV‐negative YWSS demonstrated knowledge about efficacy of condoms, 80% reported access to condoms and 58% reported using condoms consistently with the three most recent sexual partners. Knowledge about efficacy of and effective use of condoms was similar regardless of whether or not YWSS self‐identified as FSW, but YWSS self‐identifying as FSW reported better access to condoms compared to those who did not (87% vs 68%; age‐ and site‐adjusted (adjOR) = 2.69; 95% CI: 2.01 to 3.60; p < 0.001). Women who reported experiencing sexual violence in the past year and common mental disorder in the past week were less likely to use condoms consistently (43% vs. 60%; adjOR = 0.49; 95% CI: 0.35 to 0.68; p < 0.001) and (51% vs. 61%; adjOR = 0.76; 95% CI: 0.60 to 0.97; p = 0.029), respectively. Conclusions: Despite high knowledge about efficacy of and access to condoms, there remain large gaps in self‐reported consistent condom use among YWSS. Addressing the structural determinants of YWSS’ inconsistent condom use, including violence, could reduce this gap. YWSS who do not self‐identify as FSW have less access to condoms and may require additional programmatic intervention., INTRODUCTION Although HIV incidence is decreasing in sub‐Saharan Africa, it remains high among adolescent girls and young women (AGYW) aged 15 to 24 [1]. Among AGYW, young women who sell [...]

: Introduction: UNAIDS’ goal of ending AIDS by 2030 is unreachable without better targeting of testing, prevention and care. Female sex workers (FSW) in Zimbabwe are at high risk of HIV acquisition and transmission. Here, we report on collated programme and research data from Zimbabwe's national sex work programme. We also assess the potential for wider population impact of FSW programmes by modelling the impact on HIV incidence of eliminating transmission through FSW (i.e. calculate the population attributable fraction of incidence attributable to sex work). Methods: Descriptive analyses of individual‐level programme data collected from FSW between 2009 and June 2018 are triangulated with data collected through 37 respondent driven sampling surveys from 19 sites in Zimbabwe 2011 to 2017. We describe programme coverage, uptake, retention and patterns of sex work behaviour and gaps in service provision. An individual‐level stochastic simulation model is used to reconstruct the epidemic and then the incidence compared with the counter‐factual trend in incidence from 2010 had transmission through sex work been eliminated from that date. Results: Sisters has reached >67,000 FSW since 2009, increasing attendance as number of sites, programme staff and peer educators were increased. Over 57% of all FSW estimated to be working in Zimbabwe in 2017 (n = 40,000) attended the programme at least once. The proportion of young FSW reached has increased with introduction of the “Young Sisters programme.” There are no clear differences in pattern of sex work across settings. Almost all women report condom use with clients at last sex (95%); however, consistent condom use with clients in the last month varies from 52% to 95% by site. Knowledge of HIV‐positive status has increased from 48 to 78% between 2011 and 2016, as has prevalence of ART use among diagnosed women (29 to 67%). Although subject to uncertainty, modelling suggests that 70% (90% range: 32%, 93%) of all new infections in Zimbabwe from 2010 are directly or indirectly attributable to transmission via sex work. Conclusions: It is feasible to increase coverage and impact of sex work programming through community‐led scale‐up of evidence‐based interventions. Eliminating transmission through commercial sex would likely have a substantial impact on new infections occurring more widely across Zimbabwe., Introduction The UNAIDS goal of eliminating HIV by 2030 is unreachable without targeting testing, prevention and care more effectively. Despite 21 of 37 million people living with HIV (PLHIV) accessing [...]

Background: HIV prevalence and incidence has declined in East, Central, and Southern Africa (ECSA), but remains high among female sex workers (FSWs). Sex worker programmes have the potential to considerably increase access to HIV testing, prevention, and treatment. We aimed to quantify these improvements by modelling the potential effect of sex worker programmes at two different intensities on HIV incidence and key health outcomes, and assessed the programmes' potential cost-effectiveness in order to help inform HIV policy decisions., Methods: Using a model previously used to review policy decisions in ECSA, we assumed a low-intensity sex worker programme had run from 2010 until 2023; this resulted in care disadvantages among FSWs being reduced, and also increased testing, condom use, and willingness to take pre-exposure prophylaxis (PrEP). After 2023, three policy options were considered: discontinuation, continuation, and a scale-up of the programme to high-intensity, which would have a broader reach, and higher influences on condom use, antiretroviral therapy (ART) adherence, testing, and PrEP use. Outputs of the key outcomes (the percentage of FSWs who were diagnosed with HIV, on ART, and virally suppressed; the percentage of FSWs with zero condomless partners, and HIV incidence) were compared in 2030. The maximum cost for a sex worker programme to be cost-effective was calculated over a 50-year time period and in the context of 10 million adults. The cost-effectiveness analysis was conducted from a health-care perspective; costs and disability-adjusted life-years were both discounted to present US$ values at 3% per annum., Findings: Compared with continuing a low-intensity sex worker programme until 2030, discontinuation of the programme was calculated to result in a lower percentage of FSWs diagnosed (median 88·75% vs 91·37%; median difference compared to continuation of a low-intensity programme [90% range] 2·03 [-4·49 to 10·98]), a lower percentage of those diagnosed currently taking ART (86·35% vs 88·89%; 2·38 [-3·69 to 13·42]), and a lower percentage of FSWs on ART with viral suppression (87·49% vs 88·96%; 1·17 [-6·81 to 11·53]). Discontinuation of a low-intensity programme also resulted in an increase in HIV incidence among FSWs from 5·06 per 100 person-years (100 p-y; 90% range 0·52 to 22·21) to 4·05 per 100 p-y (0·21 to 21·15). Conversely, comparing a high-intensity sex worker programme until 2030 with discontinuation of the programme resulted in a higher percentage of FSWs diagnosed (median 95·81% vs 88·75; median difference compared to discontinuation [90% range] 6·36 [0·60 to 18·63]), on ART (93·93 vs 86.35%; median difference 7·13 [-0·65 to 26·48]), and with viral suppression (93·21% vs 87·49; median difference 7·13 [-0·65 to 26·48]). A high-intensity programme also resulted in HIV incidence in FSWs declining to 2·23 per 100 p-y (0·00 to 14·44), from 5·06 per 100 p-y (0·52 to 22·21) if the programme was discontinued. In the context of 10 million adults over a 50-year time period and a cost-effectiveness threshold of US$500 per disability-adjusted life-year averted, $34 million per year can be spent for a high-intensity programme to be cost-effective., Interpretation: A sex worker programme, even with low-level interventions, has a positive effect on key outputs for FSWs. A high-intensity programme has a considerably higher effect; HIV incidence among FSW and in the general population can be substantially reduced, and should be considered for implementation by policy makers., Funding: Wellcome Trust., Competing Interests: Declaration of interests LB-M and ANP have received funds paid to their institution from the Wellcome Trust for this study (grant number: 214280/Z/18/Z), the Bill & Melinda Gates Foundation, and Horizon Europe (grant number 101103140). FMC and JRH have received funds paid to their institution from the Wellcome Trust for this study. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Female sex workers remain disproportionately affected by HIV. The aim of this study was to determine the effect of risk-differentiated, peer-led support for female sex workers in Zimbabwe on the risk of HIV acquisition and HIV transmission from sex among female sex workers., Methods: In this cluster randomised, open-label, controlled study, 22 clinics dedicated to female sex workers co-located in government health facilities throughout Zimbabwe were allocated (1:1, through restricted randomisation) to usual care or AMETHIST intervention. Usual care comprised HIV testing, pre-exposure prophylaxis (PrEP), referral to government antiretroviral therapy (ART) services, contraception, condoms, syndromic management of sexually transmitted infections, health education, legal advice, and peer support. AMETHIST added peer-led microplanning tailored to individuals' risk and participatory self-help groups. All cisgender women (aged >18 years) who had sold sex within the past 30 days and lived or worked within trial cluster areas were eligible. Intervention status was not masked to programme implementers but was masked to survey teams and laboratory staff. After 28 months, a respondent-driven sampling (RDS) survey was done in the female sex worker population around each clinic, which measured the primary outcome, the combined proportion of female sex workers in the surveyed population at risk of transmitting HIV (ie, were HIV positive, not virally suppressed, and not consistently using condoms) or at risk of acquiring HIV (ie, were HIV negative and not consistently using condoms or PrEP). We report prespecified analyses of the disaggregated proportions of female sex workers in the surveyed population at risk of either transmission or acquisition of HIV. Analyses were prespecified, RDS-weighted, and age-adjusted. This trial is registered with the Pan African Clinical Trials Registry, PACTR202007818077777., Findings: The AMETHIST intervention was started on May 15, 2019, and data were collected from June 1, 2019, until Dec 13, 2021. The RDS survey was done from Oct 18 to Dec 13, 2021, with 2137 women included in the usual care group (11 clusters) and 2131 in the AMETHIST intervention group (11 clusters) after excluding survey seeds (n=132) and women with missing key data (n=44). 1973 (46·2%) of the 4268 female sex workers surveyed were living with HIV; of these, 863 (93·5%; RDS-adjusted) of 931 women in the intervention group and 927 (88·8%) of 1042 in the usual care group were virologically suppressed. 287 (22·4%) of 1200 HIV-negative women in the intervention group and 194 (15·7%) of 1096 in the usual care group reported currently taking PrEP, of whom only two (0·4%) of 569 had protective tenofovir diphosphate concentrations in dried blood spots (>700 fmol/dried blood punch). There was no effect of the intervention on the primary endpoint of risk of both HIV transmission and acquisition (intervention group n=1156/2131, RDS-adjusted proportion 55·3%; usual care group n=1104/2137, RDS-adjusted proportion 52·7%; age-adjusted risk difference -0·9%, 95% CI -5·7% to 3·9%, p=0·70). For the secondary outcomes, the proportion of women living with HIV at risk of transmission was low and significantly reduced in the intervention group (n=63/931, RDS-adjusted proportion 5·8%) compared with the usual care group (103/1041, 10·4%), with an age-adjusted risk difference of -5·5% (95% CI -8·2% to -2·9%, p=0·0003). Risk of acquisition among HIV-negative women was similar in the intervention (n=1093/1200, RDS-adjusted proportion 92·1%) and the usual care group (1001/1096, 92·2%), with an age-adjusted risk difference of -0·6% (95% CI -4·6 to 3·4, p=0·74)., Interpretation: There was no overall benefit of the intervention on combined risk of transmission or acquisition. Viral load suppression in women living with HIV was high and appeared to be further improved by AMETHIST, suggesting potential for impressive uptake and adherence to ART in vulnerable and mobile populations. Sustaining treatment and reinvigorating prevention remain crucial., Funding: The Wellcome Trust and the Bill & Melinda Gates Foundation., Translations: For the Shona and Ndebele translations of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Female sex workers' livelihoods in Zimbabwe have been severely impacted by the coronavirus disease 2019 pandemic due to closure of entertainment venues. Competition over fewer clients has reduced ability to negotiate condom use. At the same time as partner numbers have decreased, frequency of reported condomless sex has not increased, suggesting potential reduction in overall HIV and sexually transmitted infection risk and an opportunity for programmes to reach sex workers with holistic social and economic support and prevention services., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Young women who sell sex (YWSS) are at disproportionate risk of HIV. Reducing YWSS' vulnerability requires engaging their male sexual partners. To achieve this, we need to understand the characteristics and dynamics of their sexual partnerships to inform effective interventions., Methods: We conducted a mixed-methods study to compare YWSS' qualitative descriptions of male partners with categories reported in a behavioral survey. Data were drawn from enrollment into an evaluation of the DREAMS initiative in Zimbabwe in 2017. As part of a respondent-driven sampling survey, we recruited 40 seed participants from 2 intervention and 4 comparison sites. We conducted semistructured interviews with 19 "seeds," followed by a behavioral survey with 2387 YWSS. We interpreted quantitative and qualitative data together to understand how YWSS perceived male sexual partners, assess how well survey variables related to narrative descriptions, and describe patterns of risk behavior within partnerships., Results: Qualitative data suggest survey categories "husband" and "client" reflect YWSS' perceptions but "regular partner/boyfriend" and "casual partner" do not. In interviews, use of the term "boyfriend" was common, describing diverse relationships with mixed emotional and financial benefits. More than 85% of male partners provided money to YWSS, but women were less likely to report condomless sex with clients than regular partners (11% vs 37%) and more likely to report condomless sex with partners who ever forced them to have sex (37% vs 21%)., Conclusions: Reducing HIV risk among YWSS requires prevention messages and tools that recognize diverse and changing vulnerability within and between sexual relationships with different male partners., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: National-level population size estimates (PSEs) for hidden populations are required for HIV programming and modelling. Various estimation methods are available at the site-level, but it remains unclear which are optimal and how best to obtain national-level estimates., Setting: Zimbabwe., Methods: Using 2015-2017 data from respondent-driven sampling (RDS) surveys among female sex workers (FSW) aged 18+ years, mappings, and program records, we calculated PSEs for each of the 20 sites across Zimbabwe, using up to 3 methods per site (service and unique object multipliers, census, and capture-recapture). We compared estimates from different methods, and calculated site medians. We estimated prevalence of sex work at each site using census data available on the number of 15-49-year-old women, generated a list of all "hotspot" sites for sex work nationally, and matched sites into strata in which the prevalence of sex work from sites with PSEs was applied to those without. Directly and indirectly estimated PSEs for all hotspot sites were summed to provide a national-level PSE, incorporating an adjustment accounting for sex work outside hotspots., Results: Median site PSEs ranged from 12,863 in Harare to 247 in a rural growth-point. Multiplier methods produced the highest PSEs. We identified 55 hotspots estimated to include 95% of all FSW. FSW nationally were estimated to number 40,491, 1.23% of women aged 15-49 years, (plausibility bounds 28,177-58,797, 0.86-1.79%, those under 18 considered sexually exploited minors)., Conclusion: There are large numbers of FSW estimated in Zimbabwe. Uncertainty in population size estimation should be reflected in policy-making.

Background: "HIV prevention cascades" have been proposed to support programs by identifying gaps in demand for, access to, and capability to adhere to HIV prevention tools, but there are few empirical examples to guide development. We apply a prevention cascade framework to examine prevention coverage and factors associated with condoms and/or PrEP adherence among female sex workers., Setting: Seven sites across Zimbabwe., Methods: Seven respondent-driven sampling surveys from the intervention sites of a pragmatic cluster-randomized trial in Zimbabwe in 2016 were analyzed, and 611/1439 women testing HIV-negative included. We operationalized key components of an HIV prevention cascade including demand, supply, and capability to adhere to 2 tools for HIV prevention: condoms and pre-exposure prophylaxis (PrEP). We used adjusted logistic regression to identify determinants of adherence to condoms and PrEP in turn, examining the effect of adherence to one tool on adherence to the other., Results: There were 343/611, 54.7%, women reporting adherence to condoms and/or PrEP, leaving almost half uncovered. Although women were aware that condoms prevented HIV and reported good access to them, only 45·5% reported full adherence to condom use. For PrEP, a new technology, there were gaps along all 3 domains of demand, supply, and adherence. Alcohol use decreased adherence to PrEP and condoms. Younger and newer entrants to sex work were less likely to take PrEP every day., Conclusions: HIV prevention programming among female sex workers in Zimbabwe could consider increasing awareness of PrEP alongside supply, alcohol use interventions, and approaches to engaging younger women.

Background: While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions., Objective: To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained., Methods: The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe., Results: There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater., Conclusions: We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey., (©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.)