Elsevier

The Lancet

Volume 385, Issue 9962, 3–9 January 2015, Pages 72-87
The Lancet

Series
Combination HIV prevention for female sex workers: what is the evidence?

https://doi.org/10.1016/S0140-6736(14)60974-0Get rights and content

Summary

Sex work occurs in many forms and sex workers of all genders have been affected by HIV epidemics worldwide. The determinants of HIV risk associated with sex work occur at several levels, including individual biological and behavioural, dyadic and network, and community and social environmental levels. Evidence indicates that effective HIV prevention packages for sex workers should include combinations of biomedical, behavioural, and structural interventions tailored to local contexts, and be led and implemented by sex worker communities. A model simulation based on the South African heterosexual epidemic suggests that condom promotion and distribution programmes in South Africa have already reduced HIV incidence in sex workers and their clients by more than 70%. Under optimistic model assumptions, oral pre-exposure prophylaxis together with test and treat programmes could further reduce HIV incidence in South African sex workers and their clients by up to 40% over a 10-year period. Combining these biomedical approaches with a prevention package, including behavioural and structural components as part of a community-driven approach, will help to reduce HIV infection in sex workers in different settings worldwide.

Introduction

The HIV epidemic continues to have a profound effect on female, male, and transgender sex workers.1, 2, 3, 4 The median worldwide estimates show that female sex workers (FSWs) are 13·5 (95% CI 10·0–18·1) times more likely to be living with HIV than other women,3 15% of female HIV infections in 2011 were attributed to sex workers, with the highest attributable fraction in sub-Saharan African populations (17·8%).5 Substantial proportions of new infections (10–32%) occurred as a result of sex work in West African countries. In Uganda, Swaziland, and Zambia, 7–11% of new infections could be due to sex work, sex-worker clients, and clients' regular partners.6 The UNAIDS 2015 goal of zero infections and discrimination will need effective HIV prevention strategies for those who sell or barter for sex in every region.1, 4

Sex work is diverse and occurs in various contexts around the world. Although some women sell sex through formal structures such as brothels or other venues, others might work independently and solicit clients directly in public places or via cell phone or internet.7, 8 Tailoring of an effective, safe HIV prevention package for FSWs to account for the contexts in which they work and the particular risks they face is needed.7

Here, we have focused on prevention interventions for FSWs and have defined sex work as exchange of sex for money or goods. Prevention options for men (Baral and colleagues9) and transgender persons who sell sex (Poteat and colleagues10) are reviewed in this Series. HIV prevention for women is a continuing challenge, and is an area where biology, physiology, gender dynamics, and behaviour have made HIV prevention research challenging, particularly in the subset of women who sell sex. We assessed interventions in three categories: biological, behavioural, and structural.11, 12 Effective HIV prevention approaches for FSWs exist but have not been taken to scale or adequately resourced in most parts of the world.13 Additionally, we explored complementary strategies that can be added to a combination prevention package tailored for FSWs. An existing ecological model14 was modified to visualise multi-level domains of HIV risk for FSWs (figure 1). We present within these multi-level risks the evidence for biological, behavioural, and structural prevention interventions (table 1). In this model, we recommend that social justice principles are fully integrated into any package of combination approaches and that FSWs are meaningfully included in all aspects of programme design and implementation.11, 14, 15, 16 The prevention strategies enable FSWs to exert more control over their ability to prevent HIV. In addition to reducing infections in FSWs, these strategies will positively affect networks, communities, and country epidemics in different social, economic, and legal contexts.17 We modelled the effect of one such combination prevention package within the setting of the South African epidemic.

Key messages

  • Effective HIV prevention approaches for female sex workers exist but have not been taken to scale or adequately resourced in most parts of the world.

  • Prevention interventions should integrate principles of social justice and meaningfully include sex workers in programme design and implementation.

  • Existing and effective prevention interventions include condom promotion, sexually transmitted infection prevention and treatment, HIV counselling and testing, gender-based violence prevention, and economic and community empowerment.

  • Stigma and criminalisation form barriers to such interventions and a less punitive more enabling legal and medical environment is required.

  • Modelling suggests that condom promotion may have already reduced incidence in sex workers and their clients by up to 70% in South Africa. Additional biomedical interventions such as pre-exposure prophylaxis or treatment as prevention could further reduce this by 40%.

  • Both topical and oral pre-exposure prophylaxis have been proven to reduce HIV incidence in high-risk men and women. However, its effectiveness in sex workers has yet to be determined.

  • Earlier initiation of antiretroviral therapy, with the requisite access to services is likely to benefit the health of sex workers and reduce HIV incidence in their clients and others sexual partners.

  • New biomedical technologies must be additive to, and not replacements for, more established prevention modalities. Interventions that combine behavioural, biological, and structural factors have the potential to have the greatest effect on the health of sex workers, their clients, and the wider population.

Section snippets

Historical perspectives

FSWs were a key affected population in the early decades of the HIV epidemic.18 HIV research with sex workers contributed to improved knowledge about host immunity in settings of recurrent infections19 and vaginal mucosal integrity during the first microbicides trials.20, 21 Nonoxynol-9, a contraceptive product viewed as safe, was reported to be unsafe in sex work due to frequency of use and subsequent mucosal erosion.22

In Thailand, the 100% condom campaign was more than condom distribution:

Existing prevention strategies

Existing prevention strategies include behavioural and structural approaches, and sexual and reproductive health services, including condoms, counselling, testing, and supportive linkage to care for newly diagnosed FSWs. The most effective strategies have been within community-based programmes, which have intervened on the drivers of HIV transmission in FSWs including condomless sex, STIs, gender-based violence, unsafe working environments, and poor service usage due to stigma and

New prevention strategies

Combining the previous more established approaches with new, partially effective biomedical modalities is a potential new approach. In the last 3 years biomedical interventions that use antiretroviral drugs as prevention have become important. Antiretroviral drugs can protect uninfected individuals from acquiring infection (PrEP and post-exposure prophylaxis [PEP]), and can reduce infectiousness of infected partners (secondary prevention or treatment as prevention (TasP). Pre-exposure and

Modelling HIV prevention strategies: network level effect

The interventions described here have proven or plausible potential to protect the individual FSW, but the effect of these interventions at a network or community level depends on the local epidemic and setting.17 To assess the probable effect of some of these newer HIV prevention strategies for FSWs, we developed a mathematical model applied to South Africa. South Africa has a severe HIV epidemic that is generalised and driven mostly by heterosexual sex. Our objectives were to gauge the extent

Combination prevention for FSWs: five intervention levels

Scale-up of potential interventions to mitigate HIV acquisition and transmission by FSWs includes factors other than the hierarchy of scientific evidence. Acceptability in the FSW community, cost, logistics, and potential side-effects are additional factors.155, 156

The design of an FSW-tailored HIV prevention package needs an approach that recognises all levels of risk, and consists of biomedical, behavioural, and structural interventions (figure 1). The epidemic context (risk level 5) in which

Conclusions

Reducing HIV transmissions associated with sex work by making sex work safer both for the workers themselves and their clients are important components in achieving prevention services for all. This review gives evidence of an impressive array of already existing prevention modalities that can be combined and applied to reduce risk of HIV acquisition in FSW populations worldwide. New biomedical technologies, including topical and oral antiretroviral-based PrEP and earlier antiretroviral TasP,

Search strategy and selection criteria

The literature review focused on HIV prevention programmes and interventions, and in particular those that focused on the female sex worker (FSW) population. This review included observational studies, randomised controlled trials, and consensus papers or programme reports from organisations, when they were peer reviewed. We undertook a targeted web-based search of reported literature from select sites including WHO and the Joint UN Programme on HIV AIDS (UNAIDS) to retrieve information

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