Dataset Information

Mathematical Model Impact Analysis of a Real-Life Pre-exposure Prophylaxis and Treatment-As-Prevention Study Among Female Sex Workers in Cotonou, Benin.

ABSTRACT:

Background

Daily pre-exposure prophylaxis (PrEP) and treatment-as-prevention (TasP) reduce HIV acquisition and transmission risk, respectively. A demonstration study (2015-2017) assessed TasP and PrEP feasibility among female sex workers (FSW) in Cotonou, Benin.

Setting

Cotonou, Benin.

Methods

We developed a compartmental HIV transmission model featuring PrEP and antiretroviral therapy (ART) among the high-risk (FSW and clients) and low-risk populations, calibrated to historical epidemiological and demonstration study data, reflecting observed lower PrEP uptake, adherence and retention compared with TasP. We estimated the population-level impact of the 2-year study and several 20-year intervention scenarios, varying coverage and adherence independently and together. We report the percentage [median, 2.5th-97.5th percentile uncertainty interval (95% UI)] of HIV infections prevented comparing the intervention and counterfactual (2017 coverages: 0% PrEP and 49% ART) scenarios.

Results

The 2-year study (2017 coverages: 9% PrEP and 83% ART) prevented an estimated 8% (95% UI 6-12) and 6% (3-10) infections among FSW over 2 and 20 years, respectively, compared with 7% (3-11) and 5% (2-9) overall. The PrEP and TasP arms prevented 0.4% (0.2-0.8) and 4.6% (2.2-8.7) infections overall over 20 years, respectively. Twenty-year PrEP and TasP scale-ups (2035 coverages: 47% PrEP and 88% ART) prevented 21% (17-26) and 17% (10-27) infections among FSW, respectively, and 5% (3-10) and 17% (10-27) overall. Compared with TasP scale-up alone, PrEP and TasP combined scale-up prevented 1.9× and 1.2× more infections among FSW and overall, respectively.

Conclusions

The demonstration study impact was modest, and mostly from TasP. Increasing PrEP adherence and coverage improves impact substantially among FSW, but little overall. We recommend TasP in prevention packages.

SUBMITTER: Geidelberg L

PROVIDER: S-EPMC7803451 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

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Publications

Mathematical Model Impact Analysis of a Real-Life Pre-exposure Prophylaxis and Treatment-As-Prevention Study Among Female Sex Workers in Cotonou, Benin.

Geidelberg Lily L Mitchell Kate M KM Alary Michel M Mboup Aminata A Béhanzin Luc L Guédou Fernand F Geraldo Nassirou N Goma-Matsétsé Ella E Giguère Katia K Aza-Gnandji Marlène M Kessou Léon L Diallo Mamadou M Kêkê René K RK Bachabi Moussa M Dramane Kania K Lafrance Christian C Affolabi Dissou D Diabaté Souleymane S Gagnon Marie-Pierre MP Zannou Djimon M DM Gangbo Flore F Silhol Romain R Cianci Fiona F Vickerman Peter P Boily Marie-Claude MC

Journal of acquired immune deficiency syndromes (1999) 20210201 2

<h4>Background</h4>Daily pre-exposure prophylaxis (PrEP) and treatment-as-prevention (TasP) reduce HIV acquisition and transmission risk, respectively. A demonstration study (2015-2017) assessed TasP and PrEP feasibility among female sex workers (FSW) in Cotonou, Benin.<h4>Setting</h4>Cotonou, Benin.<h4>Methods</h4>We developed a compartmental HIV transmission model featuring PrEP and antiretroviral therapy (ART) among the high-risk (FSW and clients) and low-risk populations, calibrated to histo ...[more]

PMID: 33105397

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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: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:BACKGROUND:Measuring adherence to PrEP (pre-exposure prophylaxis) remains challenging. Biological adherence measurements are reported to be more accurate than self-reports and pill counts but can be expensive and not suitable on a daily basis in resource-limited countries. Using data from a demonstration project on PrEP among female sex workers in Benin, we aimed to measure adherence to PrEP and compare self-report and pill count adherence to tenofovir (TFV) disoproxil fumarate (TDF) concentration in plasma to determine if these 2 measures are reliable and correlate well with biological adherence measurements. METHODS:Plasma TFV concentrations were analyzed in samples collected at day 14 follow-up visit and months 6, 12, 18, and 24 (or at last visit when follow-up was shorter). Self-reported adherence was captured at day 14 follow-up visit and then quarterly by asking participants to report the number of missed pills within the last week. For pill count, medications were refilled monthly and participants were asked to bring in their medication bottles at each follow-up visit. Using generalized estimating equations adherence measured by self-report and pill count was compared to plasma drug concentrations. RESULTS:Of 255 participants, 47.1% completed follow-up. Weighted optimal adherence combining data from all visits was 26.8% for TFV concentration, 56.0% by self-report and 18.9% by pill count. Adherence measured by both TFV concentrations and self-report decreased over time (P?=?.009 and P?=?.019, respectively), while the decreasing trend in adherence by pill count was not significant (P?=?.087). The decrease in adherence was greater using TFV concentrations than the other 2 adherence measures. CONCLUSION:With high levels of misreporting of adherence using self-report and pill count, the objective biomedical assessment of adherence via laboratory testing is optimal and more accurately reflects PrEP uptake and persistence. Alternative inexpensive and accurate approaches to monitor PrEP adherence should be investigated.

Project description:IntroductionIn Bangalore, new HIV infections of female sex workers and men who have sex with men continue to occur, despite high condom use. Pre-exposure prophylaxis (PrEP) has high anti-HIV efficacy for men who have sex with men. PrEP demonstration projects are underway amongst Indian female sex workers. We estimated the impact and efficiency of prioritizing PrEP to female sex workers and/or men who have sex with men in Bangalore.MethodsA mathematical model of HIV transmission and treatment for female sex workers, clients, men who have sex with men and low-risk groups was parameterized and fitted to Bangalore data. The proportion of transmission attributable (population attributable fraction) to commercial sex and sex between men was calculated. PrEP impact (infections averted, life-years gained) and efficiency (life-years gained/infections averted per 100 person-years on PrEP) were estimated for different levels of PrEP adherence, coverage and prioritization strategies (female sex workers, high-risk men who have sex with men, both female sex workers and high-risk men who have sex with men, or female sex workers with lower condom use), under current conditions and in a scenario with lower baseline condom use amongst key populations.ResultsPopulation attributable fractions for commercial sex and sex between men have declined over time, and they are predicted to account for 19% of all new infections between 2016 and 2025. PrEP could prevent a substantial proportion of infections amongst female sex workers and men who have sex with men in this setting (23%/27% over 5/10 years, with 60% coverage and 50% adherence), which could avert 2.9%/4.3% of infections over 5/10 years in the whole Bangalore population. Impact and efficiency in the whole population was greater if female sex workers were prioritized. Efficiency increased, but impact decreased, if only female sex workers with lower condom use were given PrEP. Greater impact and efficiency was predicted for the scenario with lower condom use.ConclusionsPrEP could be beneficial for female sex workers and men who have sex with men in Bangalore, and give some benefits in the general population, especially in similar settings with lower condom use levels.

Dataset Information

Mathematical Model Impact Analysis of a Real-Life Pre-exposure Prophylaxis and Treatment-As-Prevention Study Among Female Sex Workers in Cotonou, Benin.

Background

Setting

Methods

Results

Conclusions

Publications

Mathematical Model Impact Analysis of a Real-Life Pre-exposure Prophylaxis and Treatment-As-Prevention Study Among Female Sex Workers in Cotonou, Benin.

Similar Datasets

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