Pre-exposure prophylaxis in real life: experience from a prospective, observational and demonstration project among men who have sex with men in Benin, West Africa.

INTRODUCTION: Since many countries in sub-Saharan Africa are willing to implement HIV oral pre-exposure prophylaxis (PrEP) for men who have sex with men (MSM), data are needed to assess its feasibility and relevance in real life. The study objectives were to assess drug uptake, adherence, condom use and number of sexual partners, HIV incidence and trends in the prevalence of gonorrhoea and chlamydia. METHODS: In this oral PrEP demonstration study conducted prospectively in Benin, a combination of tenofovir disoproxil fumarate-TDF 300 mg and emtricitabine-FTC 200 mg (TDF-FTC) was offered daily or on-demand to MSM. Participants were recruited from 24 August to 24 November 2020 and followed over 12 months. At enrolment, month-6 and month-12, participants answered to a face-to-face questionnaire, underwent a physical examination and provided blood samples for HIV, gonorrhoea and chlamydia. RESULTS: Overall, 204 HIV-negative men initiated PrEP. The majority of them (80%) started with daily PrEP. Retention rates at month-3, 6, 9 and 12 were 96%, 88%, 86% and 85%, respectively. At month-6 and month-12, respectively, 49% and 51% of the men on daily PrEP achieved perfect adherence (self-reported), that is seven pills taken during the last week. For event-driven PrEP, the corresponding proportions for perfect adherence (last seven at-risk sexual episodes covered) were 81% and 80%, respectively. The mean number (standard deviation) of male sexual partners over the last 6 months was 2.1 (1.70) at baseline and 1.5 (1.27) at month-12 (p-value for trend <0.001). Consistent condom use during the last 6 months was 34% (enrolment), 37% (month-6) and 36% (month-12). Three HIV seroconversions (2-daily and 1-event-driven) were recorded. Crude HIV incidence (95% confidence interval) was 1.53 (0.31-4.50)/100 person-years. Neisseria gonorrhoeae and/or Chlamydia trachomatis prevalence at the anal and/or pharyngeal and/or urethral sites was 28% at baseline and 18% at month-12 (p-value = 0.017). CONCLUSIONS: In West Africa, oral PrEP introduction in routine practice as a component of a holistic HIV prevention package is feasible and may not result in a significant increase in condomless sex among MSM. Since HIV incidence was still higher, additional interventions, such as culturally tailored adherence counselling, may be needed to optimize the benefits of PrEP.

Type-specific incidence, persistence and factors associated with human papillomavirus infection among female sex workers in Benin and Mali, West Africa.

OBJECTIVES: This study in female sex workers (FSWs) aimed to: (1) estimate type-specific incidence and persistence of human papillomavirus (HPV) infection in Cotonou (Benin) and Bamako (Mali); and (2) identify the factors associated with type-specific incidence and persistence of high-risk HPV (HR-HPV) infection. METHODS: A 1-year prospective cohort study on cervical cancer screening, and HPV and human immunodeficiency virus (HIV) infections was conducted among FSWs in Cotonou and Bamako from 2017 to 2019. Poisson regression models assessed factors associated with the incidence of HR-HPV infection, while log-binomial regression was performed to identify factors associated with the persistence of HR-HPV infection. Adjusted relative risks (ARR) and 95% confidence intervals (95% CI) were estimated. RESULTS: The incidence of HR-HPV infection was 46.98 per 1000 women-months (predominant types HPV16, HPV35 and HPV59). Factors associated with the incidence of HR-HPV infection were age <20 years (ARR 15.10; 95% CI 3.29-69.19), age at sexual debut <18 years (ARR 6.92; 95% CI 1.97-24.27) and sex work duration ≤1 year (ARR 7.40; 95% CI 1.84-29.69). The persistence of HR-HPV infection at 12 months was 38.7% (most persistent types HPV59, HPV52 and HPV51). Persistence of HR-HPV infection was higher in women with chlamydia (P = 0.031), HIV infection (P < 0.001) and multiple-type HPV infections (P < 0.001). CONCLUSION: FSWs in West Africa are at high risk of incident and persistent HR-HPV infection, suggesting an urgent need for cervical cancer screening in this population.

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

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.

Human papillomavirus genotype distribution and factors associated among female sex workers in West Africa.

OBJECTIVES: This study aimed to: (1) Estimate HPV prevalence and genotype distribution among female sex workers (FSWs) in Mali and Benin as well as the prevalence of multiple HPV type infections in this group, and (2) Identify potential risk factors associated with high-risk (HR) HPV infections. METHODS: We analyzed baseline data of 665 FSWs aged ≥ 18 years recruited during a prospective cohort of cervical cancer screening in Cotonou (Benin) and Bamako (Mali) from 2017 to 2018. The Linear Array HPV genotyping test was used to identify HPV genotypes. Descriptive statistics and multivariate log-binomial regression were used. Adjusted prevalence ratios (APR) with 95% confidence intervals (95%CI) were estimated to identify risk factors associated with HR-HPV infections. RESULTS: HPV data were available for 659 FSWs (Benin: 309; Mali: 350). The mean age was 35.0 years (± 10.7) in Benin and 26.8 years (± 7.6) in Mali. The overall HPV prevalence rates were 95.5% in Benin and 81.4% in Mali. About 87.7% and 63.4% of FSWs harbored ≥ 2 HPV types in Benin and Mali, respectively. The top three prevalent HR-HPV among FSWs in Benin were: HPV58 (37.5%), HPV16 (36.6%) and HPV52 (28.8%). Corresponding patterns in Mali were HPV16 (15.7%), HPV51 (14.3%) and HPV52 (12.9%). In Benin, the main factors associated with HR-HPV were vaginal douching (APR = 1.17; 95%CI:1.02-1.34) and gonococcal infection (APR = 1.16; 95%CI:1.04-1.28), while in Mali they were sex work duration ≤ 1 year (APR = 1.35; 95%CI:1.10-1.65) and HIV infection (APR = 1.26; 95%CI: 1.06-1.51). CONCLUSION: Our study found a very high prevalence of HPV infection as well as high frequency of multiple HPV type infections in FSWs in two countries in West Africa. These findings suggest the necessity to emphasize cervical cancer prevention in this high-risk group.

HIV treatment response among female sex workers participating in a treatment as prevention demonstration project in Cotonou, Benin.

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.

A novel nested polymerase chain reaction targeting the testis-specific protein Y-encoded family of genes for high sensitivity of recent semen exposure detection: Comparison with four other assays of semen detection.

OBJECTIVES: Because self-report of sexual behaviours is prone to biases, biomarkers of recent semen exposure are increasingly used to assess unprotected sex. We aimed to present a novel nested polymerase chain reaction (PCR) assay targeting testis-specific protein Y-encoded (TSPY) genes and to compare its performance in detecting recent semen exposure with that of four other assays. METHODS: Forty-five vaginal samples were selected at baseline of a prospective observational demonstration study of early antiretroviral treatment and pre-exposure prophylaxis among female sex workers in Benin. Semen exposure was assessed with: a rapid prostate-specific antigen (PSA) detection assay, a quantitative PCR targeting the sex-determining region (SRY) gene, a standard PCR targeting SRY, a standard PCR targeting TSPY, and a nested PCR targeting TSPY (n-TSPY). Because we had hypothesized that n-TSPY would be the most sensitive of the five assays while remaining specific, and as our results suggested that it was the case, sensitivity and specificity were calculated for each assay in comparison with n-TSPY. RESULTS: The n-TSPY could detect male DNA at concentration 16 and 64 times lower compared to s-TSPY and s-SRY, respectively. Among the 45 vaginal samples, prevalences of semen exposure according to the different assays varied from 22.2% (95%CI: 11.2%-37.1%) to 70.5% (95%CI: 54.8%-83.2%), with the highest prevalence measured with n-TSPY. The n-TSPY products were of expected size and we observed no false-positive in female DNA controls. The assay that offered the second best performance in detecting semen exposure was the PSA rapid test, with a sensitivity of 61.3% and a specificity of 100% compared to n-TSPY. CONCLUSIONS: Compared to n-TSPY, all other PCR assays had poor performance to detect semen exposure. The n-TSPY is an accessible assay that may have great utility in assessing semen exposure in studies where many factors are expected to accelerate biomarkers' clearance.

PrEP Use Among Female Sex Workers: No Evidence for Risk Compensation.

BACKGROUND: Little is known about risk compensation among female sex workers (FSW) on HIV pre-exposure prophylaxis (PrEP), and self-report of sexual behaviors is subject to bias. SETTING: Prospective observational PrEP demonstration study conducted among FSW in Cotonou, Benin. METHODS: Over a period of 24 months, we assessed and compared trends in unprotected sex as measured by self-report (last 2 or 14 days), by detection of sexually transmitted infections (STIs), and by vaginal detection of prostate-specific antigen and Y-chromosomal DNA, 2 biomarkers of semen exposure in the last 2 or 14 days, respectively. Trends were assessed and compared using a log-binomial regression that was simultaneously fit for all unprotected sex measures. RESULTS: Of 255 participants, 120 (47.1%) completed their follow-up. Prevalence of STI decreased from 15.8% (95% confidence interval: 11.8% to 21.0%) at baseline to 2.1% (95% confidence interval: 0.4% to 10.2%) at 24 months of follow-up (P-trend = 0.04). However, we observed no trend in self-report of unprotected sex in the last 2 (P = 0.42) or 14 days (P = 0.49), nor in prostate-specific antigen (P = 0.53) or Y chromosomal DNA (P = 0.25) over the same period. We observed no statistically significant difference between trends in self-report of unprotected sex and trends in biomarkers of semen exposure in the last 2 days (P = 0.14) or in the last 14 days (P = 0.29). CONCLUSIONS: We observed no evidence of risk compensation, and a decrease in STI among FSW on PrEP. PrEP intervention may be an opportunity to control STI among FSW. Future studies should assess risk compensation with biomarkers of semen exposure when possible.

Biological Validation of Self-Reported Unprotected Sex and Comparison of Underreporting Over Two Different Recall Periods Among Female Sex Workers in Benin.

BACKGROUND: Self-reported unprotected sex validity is questionable and is thought to decline with longer recall periods. We used biomarkers of semen to validate self-reported unprotected sex and to compare underreporting of unprotected sex between 2 recall periods among female sex workers (FSW). METHODS: At baseline of an early antiretroviral therapy and pre-exposure prophylaxis demonstration study conducted among FSW in Cotonou, Benin, unprotected sex was assessed with retrospective questionnaires, and with vaginal detection of prostate-specific antigen (PSA) and Y-chromosomal deoxyribonucleic acid (Yc-DNA). Underreporting in the last 2 or 14 days was defined as having reported no unprotected sex in the recall period while testing positive for PSA or Yc-DNA, respectively. Log-binomial regression was used to compare underreporting over the 2 recall periods. RESULTS: Unprotected sex prevalence among 334 participants was 25.8% (50.3%) according to self-report in the last 2 (or 14) days, 32.0% according to PSA, and 44.3% according to Yc-DNA. The proportion of participants underreporting unprotected sex was similar when considering the last 2 (18.9%) or 14 days (21.0%; proportion ratio = 0.90; 95% confidence interval, 0.72-1.13). Among the 107 participants who tested positive for PSA, 19 (17.8%) tested negative for Yc-DNA. CONCLUSIONS: Underreporting of unprotected sex was high among FSW but did not seem to be influenced by the recall period length. Reasons for discrepancies between PSA and Yc-DNA detection, where women tested positive for PSA but negative for Yc-DNA, should be further investigated.

Early antiretroviral therapy and daily pre-exposure prophylaxis for HIV prevention among female sex workers in Cotonou, Benin: a prospective observational demonstration study.

INTRODUCTION: In 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. METHODS: In 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. RESULTS: Among 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. CONCLUSIONS: This 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 REGISTRATION: ClinicalTrials.gov NCT02237.