HIV and trends in condom use among femal sex workers in Benin: two posters

Regroupements stratégiques

Des affiches de Katia Giguère, membre étudiante du RRSPQ, et collègues, présentées à la 19th International Conference on AIDS and STIs in Africa (ICASA 2017) Côte d’Ivoire, Décembre 2017, avec le support financier du RRSPQ.  Katia Giguère est l'une des récipiendaires du concours de soutien du RRSPQ à la participation à des conférences internationales (2017-2018). Félicitations! Katia Giguère is one of the winners of the Winter 2017-2018 QPHRN competition "Support for the participation in international conferences". Congratulations!

Click on the titles to access the posters - Cliquez sur les titres pour accéder aux affiches.

 

Poster 1: Validation of self-reported condom use with biomarkers of semen exposure among female sex workers in Cotonou, Benin

Author(s):

Giguère Katia1,2 , Béhanzin Luc1,3,4, Guédou Fernand1,3,4, Goma Ella3, Leblond François A.5, Zannou Djimon Marcel6,7, Alary Michel1,2,8

1Centre de recherche du CHU de Québec - Université Laval, Québec, Canada,
2Département de médecine sociale et préventive - Université Laval, Québec, Canada
3Dispensaire IST, Cotonou, Benin
4École Nationale de Formation des Techniciens Supérieurs en Santé Publique et en Surveillance Épidémiologique, Université de Parakou, Parakou, Benin
5Consultant indépendant, Montréal, Canada
6Faculté des sciences de la santé, Université d'Abomey-Calavi, Cotonou, Benin
7Centre national hospitalier universitaire HMK, Cotonou, Benin, 8Institut national de santé publique du Québec, Québec, Canada

Abstract

Background : Unprotected sex is a major risk factor of HIV infection among female sex workers (FSW). Self-report of unprotected sex is prone to information biases but it turns out that vaginal detection of prostate-specific antigen (PSA) or of Y-chromosomal DNA (Yc-DNA), two biomarkers of semen exposure, allows for an objective detection of unprotected sex that occurred in the last 2 or 14 days, respectively.

Objectives : To validate self-reported unprotected sex using PSA and Yc-DNA testing among FSW in Cotonou, Benin.

Methods : This cross-sectional study uses baseline data from a prospective cohort study aiming to verify the feasibility of implementing early treatment as HIV prevention and preexposure prophylaxis among FSW from Cotonou in Benin. At baseline, unprotected sex in the previous 2 or 14 days was assessed by face-to-face interviews and a vaginal sample was collected for PSA and Yc-DNA testing. The proportion of FSW who self-reported unprotected sex, who tested positive for the biomarkers, as well as the proportion of FSW who under-reported unprotected sex (reported no unprotected yet testing positive for the biomarker) were calculated and compared together using generalized estimating equations to account for the dependence between the observations.

Results:  A total of 361 FSW were enrolled between October 2014 and November 2016. Analyses were restricted to the 334 (92.5%) FSW who had complete data for the four different measures of unprotected sex. Results suggest that the proportion of unprotected sex in the last 2 days was 34% higher (Prevalence ratio (PR)=1.34; 95% confidence interval (CI): 1.04-1.74) when measured by PSA (32.0%; 95%CI: 26.9-38.0%) rather than by selfreport (23.8%; 95%CI: 19.1-29.8%). The proportion of under-reporting in the last 2 days was estimated at 20.1% (95%CI: 15.9-25.1%). Although the proportion of unprotected sex in the last 14 days was similar (PR=0.96; 95%CI: 0.80-1.14) when measured by Yc-DNA (45.2%; 95%CI: 39.8-51.3%) or self-report (47.3; 95%CI: 41.4-54.0%), under-reporting was observed and estimated to 22.5% (95%CI: 18.3-27.8%).

Conclusions and Recommendations: Our results suggest that unprotected sex in the last 2 or 14 days was under-reported by more than 20% of the FSW in Cotonou. Social desirability bias is currently the main explanation for under-reporting. However, additional studies on its determinants in this population could be useful in order to improve self-report of unprotected sex in future work.

 

Poster 2: Trends in condom use among female sex workers participating in a demonstration study on HIV treatment as prevention and pre-exposure prophylaxis in Cotonou, Benin

Author(s):

Giguère Katia1,2 , Béhanzin Luc1,3,4, Guédou Fernand1,3,4, Goma Ella3, Leblond François A.5, Zannou Djimon Marcel6,7, Alary Michel1,2,8

1Centre de recherche du CHU de Québec - Université Laval, Québec, Canada,
2Département de médecine sociale et préventive - Université Laval, Québec, Canada
3Dispensaire IST, Cotonou, Benin
4École Nationale de Formation des Techniciens Supérieurs en Santé Publique et en Surveillance Épidémiologique, Université de Parakou, Parakou, Benin
5Consultant indépendant, Montréal, Canada
6Faculté des sciences de la santé, Université d'Abomey-Calavi, Cotonou, Benin
7Centre national hospitalier universitaire HMK, Cotonou, Benin, 8Institut national de santé publique du Québec, Québec, Canada

Abstract

Background: The introduction of new HIV prevention methods in a population may result in condom migration. This is why condom use should be monitored in the demonstration study on HIV treatment as prevention (TasP) and pre-exposure prophylaxis (PrEP) carried out in Cotonou, Benin. Self-report of unprotected sex is prone to information biases, but it turns out that vaginal detection of prostate-specific antigen (PSA) or of Y-chromosomal DNA (Yc-DNA), two biomarkers of semen exposure, allows for an objective detection of unprotected sex that occurred in the last 2 or 14 days, respectively.

Objectives: To compare trends of unprotected sex as measured by self-report and by PSA and Yc-DNA testing among female sex workers (FSW) from Cotonou, Benin.

Methods: A prospective study aiming to verify the feasibility of implementing TasP and PrEP among FSW was conducted from September 2014 to December 2016 in Cotonou, Benin. At baseline and at the 6-, 12-, 18-, and 24-month follow-up visits, unprotected sex in the previous 2 or 14 days was assessed by face-to-face interviews and a vaginal sample was collected for PSA and Yc-DNA testing. Trends of unprotected sex as measured by selfreport or biomarkers were assessed and compared together using generalized estimating equations. Inverse probability weighting was applied to correct for the selection bias caused by attrition.

Results: Among 360 FSW (3709 observations) of the 361 enrolled in the TasP/PrEP study, from baseline to the 24-month visit, self-reported unprotected sex in the last 2 days varied from 23.8% (95% Confidence interval (CI): 19.3-29.5%) to 15.1% (95%CI: 4.3-53.2%)(ptrend=0.67). In the last 14 days, self-reported unprotected sex varied from 47.3% (95%CI: 41.7-53.7%) to 30.9% (95%CI: 17.7-53.7%)(p-trend=0.18). According to PSA, the proportion of unprotected sex varied from 32.4% (95%CI: 27.6-38.2%) to 35.6% (95%CI: 21.3-59.4%)(p-trend=0.32). Finally, according to Yc-DNA, unprotected sex varied from 46.6% (95%CI: 41.3-52.5%) to 49.6% (95%CI: 34.6-71.0%)(p-trend=0.38). No significant difference was observed when comparing the four trends using interaction terms in the model (p=0.08).

Conclusions and Recommendations: Our results suggest that there was no condom migration over the course of the TasP/PrEP study. Moreover, trends of self-reported unprotected sex do not differ from trends measured objectively. This suggests that face-to face interview remains a good tool to measure condom use trends.