Dataset Information

Positive impact of increases in condom use among female sex workers and clients in a medium HIV prevalence epidemic: modelling results from Project SIDA1/2/3 in Cotonou, Benin.

ABSTRACT:

Background

A comprehensive, HIV prevention programme (Projet Sida1/2/3) was implemented among female sex workers (FSWs) in Cotonou, Benin, in 1993 following which condom use among FSWs increased threefold between 1993 and 2008 while FSW HIV prevalence declined from 53.3% to 30.4%.

Objective

Estimate the potential impact of the intervention on HIV prevalence/incidence in FSWs, clients and the general population in Cotonou, Benin.

Methods and findings

A transmission dynamics model parameterised with setting-specific bio-behavioural data was used within a Bayesian framework to fit the model and simulate HIV transmission in the high and low-risk population of Cotonou and to estimate HIV incidence and infections averted by SIDA1/2/3. Our model results suggest that prior to SIDA1/2/3 commercial sex had contributed directly or indirectly to 93% (84-98%) of all cumulative infections and that the observed decline in FSWs HIV prevalence was more consistent with the self-reported post-intervention increase in condom use by FSWs than a counterfactual assuming no change in condom use after 1993 (CF-1). Compared to the counterfactual (CF-1), the increase in condom use may have prevented 62% (52-71%) of new HIV infections among FSWs between 1993 and 2008 and 33% (20-46%) in the overall population.

Conclusions

Our analysis provides plausible evidence that the post-intervention increase in condom use during commercial sex significantly reduced HIV prevalence and incidence among FSWs and general population. Sex worker interventions can be effective even in medium HIV prevalence epidemics and need to be sustained over the long-term.

SUBMITTER: Williams JR

PROVIDER: S-EPMC4105482 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Positive impact of increases in condom use among female sex workers and clients in a medium HIV prevalence epidemic: modelling results from Project SIDA1/2/3 in Cotonou, Benin.

Williams John R JR Alary Michel M Lowndes Catherine M CM Béhanzin Luc L Labbé Annie-Claude AC Anagonou Séverin S Ndour Marguerite M Minani Isaac I Ahoussinou Clément C Zannou Djimon Marcel DM Boily Marie-Claude MC

PloS one 20140721 7

<h4>Background</h4>A comprehensive, HIV prevention programme (Projet Sida1/2/3) was implemented among female sex workers (FSWs) in Cotonou, Benin, in 1993 following which condom use among FSWs increased threefold between 1993 and 2008 while FSW HIV prevalence declined from 53.3% to 30.4%.<h4>Objective</h4>Estimate the potential impact of the intervention on HIV prevalence/incidence in FSWs, clients and the general population in Cotonou, Benin.<h4>Methods and findings</h4>A transmission dynamics ...[more]

PMID: 25047804

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Project description:OBJECTIVES:Female sex workers (FSWs) play a key role in HIV transmission in West Africa, while they have limited access to antiretroviral therapy (ART). In line with UNAIDS recommendations extending ART to all HIV-infected individuals, we conducted this demonstration project on immediate treatment as prevention (TasP) among FSWs in Cotonou, Benin. We report data on treatment response and its relation to adherence, as well as on ART-resistant genotypes. METHODS:Complete follow-up varied between 12 and 24 months. At each three-monthly visit, a questionnaire was administered, clinical examinations were carried out and blood samples collected. Adherence to treatment was estimated by self-report. Viral RNA was genotyped at baseline and final visits for drug resistance. Generalized estimating equations for repeated measures with a log-binomial link were used to analyze time trends and the association between adherence and virological response to treatment. RESULTS:One-hundred-seven HIV-positive and ART-naive FSWs were enrolled; 59.8% remained in the cohort till study completion and 62.6% had a final visit. Viral load<1000 (below quantification limit [<50]) was attained in 73.1% (64.6%) of participants at month-6, 84.8% (71.2%) at month-12, and 80.9% (65.1%) at the final visit. The proportion of women with suppressed (below quantification limit) viral load increased with increasing self-reported adherence (p = 0.06 (0.003), tests for trend). The proportion of participants with CD4≤500 also decreased drastically throughout follow-up (p < .0001). Twelve participants exhibited ART-resistant genotypes at baseline, but only two at their final visit. CONCLUSION:Our findings indicate that TasP is widely accepted among FSWs in Cotonou and could be implemented with relative success. However, due to mobility in this population, follow-up was sub-optimal, suggesting that large geographical coverage of FSW-friendly clinics is needed for sustained treatment implementation. We also fell short of the UNAIDS objective of 90% viral suppression among treated patients, underlining the need for better adherence support programs.

Project description:Female sex workers (FSWs) continue to carry a heavy burden of sexually transmitted infections (STI). For prevention purposes, there is a need to identify most-at-risk subgroups among them. The objective of this longitudinal cohort study conducted at Dispensaire IST, Cotonou, Benin, was to assess Neisseria gonorrhoeae (NG) / Chlamydia trachomatis (CT) incidence and determinants; and HIV incidence among FSWs in presence of STI/HIV risk reduction activities. Overall, 319 adult FSWs were followed quarterly from September 2008 to March 2012. NG/CT were detected from endocervical swabs by Amplified DNA Assays employing Strand displacement amplification technology. HIV testing was done on capillary blood using two consecutive rapid diagnostic tests. Anderson-Gill proportional hazard models (HR) were used to determine factors independently associated with NG/CT incidence. The majority of FSWs were HIV-negative (188, 58.9%). There were 6 HIV seroconversions among these 188 HIV-negative women. HIV incidence (95% Confidence interval, CI) was 1.41 (0.28-2.54) seroconversions per 100 person-years at risk (PYAR): 6 events / 425.1 PYAR. Sixty-two out of 319 women experienced 83 new episodes of NG/CT for an overall incidence rate (95% CI) of 10.8 (8.17-13.88) events / 100 PYAR. From month-24 onwards, HIV-positive women (treated: HR (95%CI): 4.2 (1.60-10.77); untreated: HR (95%CI): 4.2 (1.59-11.49) were more likely to acquire NG/CT compared to HIV-negative FSWs. Longer duration in sex work (>2 years: HR; 95%CI: 0.4 (0.22-0.72)) was protective against NG/CT. Refusal by clients (55.8%) was the main reason for non-condom use. Enrolling women from one clinic (Dispensaire IST) may have impaired generalizability of the findings. New NG/CT/HIV infections were observed among FSWs notwithstanding ongoing prevention interventions. To eliminate HIV transmission among FSWs, STI/HIV control programs need to promote women's empowerment and address vulnerability to infection of HIV-positive FSWs.

Project description:IntroductionIn sub-Saharan Africa, HIV prevalence remains high, especially among key populations. In such situations, combination prevention including clinical, behavioural, structural and biological components, as well as adequate treatment are important. We conducted a demonstration project at the Dispensaire IST, a clinic dedicated to female sex workers (FSWs) in Cotonou, on early antiretroviral therapy (E-ART, or immediate "test-and-treat") and pre-exposure prophylaxis (PrEP). We present key indicators such as uptake, retention and adherence.MethodsIn this prospective observational study, we recruited FSWs from October 4th 2014 to December 31st 2015 and followed them until December 31st 2016. FSWs were provided with daily tenofovir disoproxil fumarate/emtricitabine (Truvada® ) for PrEP or received a first-line antiretroviral regimen as per Benin guidelines. We used generalized estimating equations to assess trends in adherence and sexual behaviour.ResultsAmong FSWs in the catchment area, HIV testing coverage within the study framework was 95.5% (422/442). At baseline, HIV prevalence was 26.3% (111/422). Among eligible FSWs, 95.5% (105/110) were recruited for E-ART and 88.3% (256/290) for PrEP. Overall retention at the end of the study was 59.0% (62/105) for E-ART and 47.3% (121/256) for PrEP. Mean (±SD) duration of follow-up was 13.4 (±7.9) months for E-ART and 11.8 (±7.9) months for PrEP. Self-reported adherence was over 90% among most E-ART participants. For PrEP, adherence was lower and the proportion with 100% adherence decreased over time from 78.4% to 56.7% (p-trend < 0.0001). During the 250.1 person-years of follow-up among PrEP initiators, two seroconversions occurred (incidence 0.8/100 person-years (95% confidence interval: 0.3 to 1.9/100 person-years)). The two seroconverters had stopped using PrEP for at least six months before being found HIV-infected. In both groups, there was no evidence of reduced condom use.ConclusionsThis study provides data on key indicators for the integration of E-ART and PrEP into the HIV prevention combination package already offered to FSWs in Benin. PrEP may be more useful as an individual intervention for adherent FSWs rather than a specific public health intervention. E-ART was a more successful intervention in terms of retention and adherence and is now offered to all key populations in Benin.Study registrationClinicalTrials.gov NCT02237.

Project description:Social and structural influences of condom negotiation among female sex workers (FSWs) remain understudied. This study assesses environmental and individual factors associated with condom negotiation among FSWs at high risk for acquiring HIV in a large urban setting of Metro Manila, Philippines.Female bar/spa workers (N = 498), aged 18 and over, underwent interview-led surveys examining their sexual health practices in the context of their risk environments. Data were collected from April 2009-January 2010 from 54 venues. Multiple logistic regressions were conducted to assess socio-behavioral factors (e.g., age, education, length of time employed as an entertainer, and alcohol/drug use) and socio-structural factors (e.g., venue-level peer/manager support, condom rule/availability, and sex trafficking) associated with condom negotiation, adjusting for individuals nested within venues.Of 142 FSWs who traded sex in the previous 6 months (included in the analysis), 24% did not typically negotiate condom use with venue patrons. Factors in the physical environment--trafficked/coerced into work (AOR = 12.92, 95% CI = 3.34-49.90), economic environment--sex without a condom to make more money (AOR = 1.52, 95% CI 1.01-2.30), policy environment--sex without a condom because none was available (AOR = 2.58, 95% CI = 1.49-4.48), and individual risk--substance use (AOR = 2.36, 95% CI = 1.28-4.35) were independently associated with FSWs' lack of condom negotiation with venue patrons.Factors in the physical, economic, and policy environments, over individual (excepting substance use) and social level factors, were significantly associated with these FSWs' condom negotiations in the Philippines. Drawing upon Rhodes' risk environment framework, these results highlight the need for policies that support safer sex negotiations among sex workers in the context of their risk environments. Interventions should reduce barriers to condom negotiation for FSWs trafficked/coerced into their work, substance using, and impacted by economic conditions and policies that do not support condom availability.

Project description:BackgroundAlthough female sex workers (FSWs) report high levels of condom use with commercial sex clients, particularly after targeted HIV preventive interventions have been implemented, condom use is often low with non-commercial partners. There is limited understanding regarding the factors that influence condom use with FSWs' non-commercial partners, and of how programs can be designed to increase condom use with these partners. The main objectives of this study were therefore to describe FSWs' self-reported non-commercial partners, along with interpersonal factors characterizing their non-commercial partnerships, and to examine the factors associated with consistent condom use (CCU) within non-commercial partnerships.MethodsThis study used data collected from cross-sectional questionnaires administered to 988 FSWs in four districts in Karnataka state in 2006-07. We used bivariate and multivariable logistic regression analysis to examine the relationship between CCU (i.e., 'always' compared to 'never', 'sometimes' or 'frequently') with non-commercial partners of FSWs (including the respondents' husband or main cohabiting partner [if not married] and their most recent non-paying partner [who is neither a husband nor the main cohabiting partner, and with whom the FSW had sex within the previous year]) and interpersonal factors describing these partnerships, as well as social and environmental factors. Weighting and survey methods were used to account for the cluster sampling design.ResultsOverall, 511 (51.8%) FSWs reported having a husband or cohabiting partner and 247 (23.7%) reported having a non-paying partner. CCU with these partners was low (22.6% and 40.3% respectively). In multivariable analysis, the odds of CCU with FSWs' husband or cohabiting partner were 1.8-fold higher for FSWs whose partner knew she was a sex worker (adjusted odds ratio [AOR]: 1.84, 95% confidence intervals[CI]: 1.02-3.32) and almost 6-fold higher if the FSW was unmarried (AOR: 5.73, 95%CI: 2.79-11.76]. CCU with FSWs' non-paying partner decreased by 18% for each one-year increase in the duration of the relationship (AOR: 0.82, 95%CI: 0.68-0.97).ConclusionsThis study revealed important patterns and interpersonal determinants of condom use within non-commercial partnerships of FSWs. Integrated structural and community-driven HIV/STI prevention programs that focus on gender and reduce sex work stigma should be investigated to increase condom use in non-commercial partnerships.

Project description:BackgroundThe incidence of HIV infection among female sex workers and their clients in the Middle East and north Africa is not well known. We aimed to assess HIV incidence, the contribution of heterosexual sex work networks to these numbers, and the effect of interventions by use of mathematical modelling.MethodsIn this modelling study, we developed a novel, individual-based model to simulate HIV epidemic dynamics in heterosexual sex work networks. We applied this model to 12 countries in the Middle East and north Africa that had sufficient data to estimate incidence in 2020 and the impact of interventions by 2030 (Algeria, Bahrain, Djibouti, Iran, Libya, Morocco, Pakistan, Somalia, South Sudan, Sudan, Tunisia, and Yemen). Model-input parameters were provided through a systematic review of HIV prevalence, sexual and injecting behaviours, and risk group size estimates of female sex workers and clients. Model output was number of incident HIV infections under different modelling scenarios for each country. Summary statistics were generated on these model output scenarios.FindingsBased on the output of our model, we estimated a total of 14 604 (95% uncertainty interval [UI] CI 7929-31 819) new HIV infections in the 12 countries in 2020 among female sex workers, clients, and spouses, which constituted 28·1% of 51 995 total new cases in all adults in these 12 countries combined. Model-estimated number of new infections in 2020 in the 12 countries combined was 3471 (95% UI 1295-10 308) in female sex workers, 6416 (3144-14 223) in clients, and 4717 (3490-7288) in client spouses. Contribution of incidence in heterosexual sex work networks to total incidence varied widely, ranging from 3·3% in Pakistan to 71·8% in South Sudan and 72·7% in Djibouti. Incidence in heterosexual sex work networks was distributed roughly equally among female sex workers, clients, and client spouses. Estimated incidence rates among female sex workers per 1000 person-years ranged from 0·4 (95% UI 0·0-7·1) in Yemen to 34·3 (17·2-59·6) in South Sudan. In countries where HIV acquisition through injecting drug use creates substantial exposure for female sex workers who inject drugs, estimated incidence rates per 1000 person-years ranged from 5·1 (95% UI 0·0-35·1) in Iran to 45·8 (0·0-428·6) in Pakistan. The model output predicted that any of the programmed interventions would substantially reduce incidence. Even when a subpopulation did not benefit directly from an intervention, it benefited indirectly through reduction in onward transmission, and indirect impact was often half as large as the direct impact.InterpretationSubstantial HIV incidence occurs in heterosexual sex work networks across the Middle East and north Africa with client spouses being heavily affected, in addition to female sex workers and clients. Rapid scaling-up of comprehensive treatment and prevention services for female sex workers is urgently needed.FundingQatar National Research Fund (a member of Qatar Foundation), the Biostatistics, Epidemiology, and Biomathematics Research Core at the Weill Cornell Medicine-Qatar, Qatar University-Marubeni, the UK Medical Research Council, and the UK Department for International Development.

Dataset Information

Positive impact of increases in condom use among female sex workers and clients in a medium HIV prevalence epidemic: modelling results from Project SIDA1/2/3 in Cotonou, Benin.

Background

Objective

Methods and findings

Conclusions

Publications

Positive impact of increases in condom use among female sex workers and clients in a medium HIV prevalence epidemic: modelling results from Project SIDA1/2/3 in Cotonou, Benin.

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