Prévention du VIH chez les femmes travailleuses du sexe de Conakry, République de Guinée : conseil dépistage volontaire, comportements à risque et infections sexuellement transmissibles

Background: Female sex workers (FSW) constitute the population most at risk for HIV infection in many countries of Sub-Saharan Africa. Several interventions have been implemented in this population to reduce the risk of infection. These interventions include the promotion of condom use and the screening and treatment of sexually transmitted infections (STI). However, some components are poorly represented among the interventions offered to FSW. Voluntary counselling and testing could be a useful intervention of primary and secondary prevention for this population but the acceptability of this intervention by FSW is little-known. In addition, in terms of surveillance of the epidemics, the evaluation of the validity of self-reported condom use is important as this indicator is frequently used in population surveys. More information is also needed about the importance of the desire for children in using inconsistently condoms with the main non-paying regular partner. Finally, the prevalence of STIs such as HPV-16 and the combined impact of sociodemographic, behavioural and preventive factors on HIV/STIs infection in this population need to be assessed. Objectives: The objectives of this thesis are 1) to measure the acceptability and the consequences of voluntary HIV counselling and testing among FSW in Conakry, Guinea; 2) to assess the validity of self-report condom use in this population through a biological indicator of semen, the prostate specific antigen (PSA); 3) to measure condom use with clients and non-client partners of FSW and to study the importance of the desire for children in inconsistent condom use with the main regular non-client partner and 4) to measure the prevalence of STIs and HIV and the socio-demographic, behavioural and preventive factors related to these infection outcomes. Methodology: We conducted a longitudinal study in the city of Conakry, Guinea among 421 FSW recruited in three health centers adapted for FSW. A longitudinal mixed design allowed for quantitative and qualitative data collections at baseline and one year later. Biological screening tests for STIs and HIV were performed. Results: The first article presented in this thesis showed that the acceptability of voluntary counselling and testing is high among FSW. The acceptance rate of testing, the return rate for results and disclosure of HIV status were close to 100%. This acceptability seemed to be the result of a high risk perception of HIV infection and of social pressure on FSW by the sex work stakeholders to undergo testing and to disclose their serostatus. Negatives consequences to VCT were rare. The second paper showed that self-reported recent condom use had a very low sensitivity when compared to the gold standard. Thus, most women in whom the PSA was found did not report any recent unprotected intercourse. The discrepancy between self-reported recent condom use and the presence of PSA was associated with a perceived high risk of HIV infection.   The third section showed that while condom use was very common with clients, it was much less with non-client regular partners. The desire for pregnancy among SW contributed significantly to inconsistent condom use with this type of sexual partner. Socio-demographic characteristics, behavioural factors and co-infection with other STIs were associated with the presence of STIs and HIV, which were common despite all the interventions that were conducted in this population. Conclusion: In conclusion, HIV prevention among FSW is a challenge requiring the development of integrated strategies that take into account the commercial context in which these interventions are implemented but also FSW’s childbearing aspirations.

Keyphrases: HIV, Female sex workers, Prevention, Testing, Condom use, Sexually transmitted infections