When the presumption of innocence is not beneficial : periodic presumptive treatment for STIs and HIV in female sex workers

The recent announcement that a prime-boost combination of two HIV vaccine candidates had a partial protective efficacy of around 31% in phase III clinical trials in Thailand is encouraging, but for the foreseeable future the prevention of HIV acquisition will continue to require a multifactorial response. In resource-poor countries where heterosexual transmission is the dominant mode of infection, the promotion of evidence-based behavioural and biomedical prevention strategies that effectively reach vulnerable individuals most at risk of HIV and sexually transmitted infections are paramount. Female sex workers (FSWs) and their clients may represent a significant source of new HIV infections, particularly in the early stages of the epidemic. Although 100% condom usage is the gold standard for HIV and STI risk reduction for FSWs and their clients, condoms are not always available, nor are they always used, due to women’s limited ability to negotiate safer sexual practices in commercial or transactional relationships.