Demonstration Project of Early Antiretroviral Therapy and Pre-exposure Prophylaxis for HIV Prevention Among Female Sex Workers in Cotonou, Benin

At the end of 2012, sub-Saharan Africa was home to 71% of the 35.3 million people living with HIV worldwide. Despite all the preventive and therapeutic efforts accomplished so far, the epidemic is persisting with approximately 1,600,000 new HIV infections occurring yearly in this region that is characterized by different epidemiological profiles. In West Africa, the epidemic is disproportionally concentrated among female sex workers (FSWs) who are involved directly or indirectly in 75% to 90% of HIV transmission cases towards the general population through "bridging" populations, essentially their clients and other male sexual partners. Hence, to achieve the control of the epidemic in this sub-region, especially in West Africa where the epidemic is much less generalized than in many other parts of the continent, it is important to tailor combination prevention including behavioural, structural, and biological components for the sex work milieu in general and FSWs in particular, in addition to ensuring adequate treatment of those already HIV-infected. However, despite substantial efforts in usual prevention methods in the last 10 years and effective reductions in the prevalence of HIV and other sexually transmitted infections (STIs) with concomitant increases in condom use in some countries, HIV prevalence is still high among FSWs in West Africa, with these highly vulnerable women having an HIV prevalence over 12 times higher than other women of reproductive age. Such a situation could constitute a threat to the progress achieved in controlling the HIV epidemic in this region.

Recently, in addition to previous preventive methods, such as consistent condom use and male circumcision, early treatment (treatment as prevention, TasP) has been shown to decrease HIV transmission by 96% in serodiscordant couples, whereas pre-exposure prophylaxis (PrEP) based on Tenofovir disoproxil fumarate or on the latter drug plus Emtricitabine (Truvada®) has been found to be 45 to 75% protective against HIV acquisition in four randomized controlled trials when used orally; no protection at all was observed in two trials conducted among women at high risk in African countries. These failures have now been shown to be mainly related to issues of poor adherence to the study drugs rather than poor biological efficacy. On the other hand, when combining data from several trials, the level of protection against HIV acquisition reached 90% among the sub-groups of trial participants achieving high levels of compliance. Based on the generally positive results obtained. Truvada® is now approved for PrEP by the Food and Drug Administration (FDA) in the USA. According to the Centers for Disease Control and Prevention, PrEP is largely considered a preventive individual-level intervention. However, it could potentially also have an impact at the population-level and help control the HIV epidemic if rolled out and adopted on a large scale for HIV prevention, especially among the most vulnerable populations. However, the feasibility of this approach is somewhat questioned by the low treatment adherence levels achieved in trials recruiting specifically highly vulnerable women in Africa. On the other hand, TasP can be viewed as a more classical public health intervention, as its population-level impact will largely depend on the coverage achieved in people at risk of transmitting HIV. However, the trial demonstrating TasP efficacy was carried out in serodiscordant couples, a population where treatment adherence may well be higher than in high-risk women who do not have a stable partner and who have shown lower levels of compliance than most other groups in the PrEP trials.

So far, antiretroviral therapy (ART) for all HIV-infected people, irrespective of their CD4 levels or clinical status (equivalent to TasP), is only recommended in the USA. However, the World Health Organization (WHO) and the United Nations Programme on HIV/AIDS (UNAIDS) have recently changed their recommendations on HIV treatment initiation of HIV positive individuals, increasing the eligibility criteria to treat when CD4 levels reach 500 cells/mm3 compared to the previously recommended threshold of CD4<350 cells/mm3. However, these changes have so far not been widely implemented at the country-level. Despite the proven efficacy of TasP and PrEP as prevention strategies in clinical trials, their efficiency must be evaluated in 'real life' situations, in various countries with specific cultural contexts, largely because the uptake of HIV testing, the acceptance of early treatment and PrEP as well as drug adherence may vary considerably according to personal, social and cultural characteristics, as clearly reflected by the variability in PrEP trial results. The absence of clear recommendations on both prevention strategies in different countries is partly due to the lack of evidence based on real world implementation especially amongst FSWs. The investigators are thus proposing this demonstration project among FSWs in Cotonou, Benin, to identify the best way to successfully implement TasP and PrEP in this specific setting. Benin is facing a concentrated epidemic with HIV prevalence estimated at 1.2% in a recent general population household survey, whereas HIV prevalence was estimated at 21% among FSWs in the latest integrated biological and behavioural survey (IBBS) carried out in 2012.

The project will use a field approach readily inserted within an ongoing combination prevention intervention, including clinical (for ex.: HIV testing and care, STI care) , behavioural (for ex.: non-governmental organization- and peer-led condom promotion) and structural components (for ex.: community empowerment, advocacy to decrease police harassment; community development activities leading to the constitution of FSW-led community based organizations), that the investigators implement in close collaboration with the National AIDS Control Programme (NACP) in most of the major cities and towns of Benin through a grant from the Canadian Institutes of Health Research (CIHR). The Dispensaire IST (DIST), a STI clinic dedicated to FSWs in Cotonou, will be the study clinic for this project.

TasP makes sense as a public health intervention as long as high levels of coverage are achieved in the high-frequency transmitter population targeted by this intervention. Hence, the TasP component of the project will benefit from the ongoing CIHR/NACP interventions aimed at increasing HIV testing among FSWs. Indeed, within this context, the investigators are currently carrying out a study on the determinants of regular HIV testing, based on the Theory of planned behaviour. The results of this study will be used to develop an education program promoting 3-monthly HIV testing among FSWs that will be ready to implement prior to the beginning of recruitment in the proposed study. The development of this program will use the intervention mapping approach. Its implementation is already planned in all the coverage area of our ongoing CIHR project. The latter project will also contribute by defining precise indicators of success specifically for professional FSWs (e.g. those whose main source of income is sex work who will constitute our target population), based on accurate estimations of their population size. Indeed, the investigators are currently conducting a detailed scientific mapping of the FSW population in the cities and towns covered by our ongoing intervention. The results of this size estimation study will be available before the end of 2013 and will be used to establish the denominators for the testing and TasP coverage indicators.