HIV risk and preventive interventions in transgender women sex workers

Abstract

Worldwide, transgender women who engage in sex work have a disproportionate risk for HIV compared with natal male and female sex workers. We reviewed recent epidemiological research on HIV in transgender women and show that transgender women sex workers (TSW) face unique structural, interpersonal, and individual vulnerabilities that contribute to risk for HIV. Only six studies of evidence-based prevention interventions were identified, none of which focused exclusively on TSW. We developed a deterministic model based on findings related to HIV risks and interventions. The model examines HIV prevention approaches in TSW in two settings (Lima, Peru and San Francisco, CA, USA) to identify which interventions would probably achieve the UN goal of 50% reduction in HIV incidence in 10 years. A combination of interventions that achieves small changes in behaviour and low coverage of biomedical interventions was promising in both settings, suggesting that the expansion of prevention services in TSW would be highly effective. However, this expansion needs appropriate sustainable interventions to tackle the upstream drivers of HIV risk and successfully reach this population. Case studies of six countries show context-specific issues that should inform development and implementation of key interventions across heterogeneous settings. We summarise the evidence and knowledge gaps that affect the HIV epidemic in TSW, and propose a research agenda to improve HIV services and policies for this population.

Figure 1

HIV prevention intervention systematic search protocol and results CDC=Centers for Disease Control and Prevention. IAS=International AIDS Society. NIH=National Institutes of Health.

Figure 2. Conceptual framework for selected factors leading to increased HIV infection risk in TSW

Horizonal arrows show the association between higher level and biological factors, whereas vertical arrows show how effects in one domain can propogate to other domains. TSW=transgender women sex workers. STI=sexually transmitted infection. ART=antiretroviral therapy.

Figure 3. Proportion of new infections averted in transgender women sex workers (TSW) over 10 years with each intervention in isolation and in combination in Lima, Peru and San Francisco, CA, USA

The histograms are the best-fitting baseline epidemiological scenario. The error bars are the minimum and maximum effects obtained for the ten best epidemiological scenarios. A=condom use with clients (+20%). B=condom use with stable partners (+20%). C=number of commercial transactions (–20%). D=pre-exposure prophylaxis to 20% of all TSW (44% effectiveness). E=test and treat in TSW and stable partners (40% 2 years after infection in Lima, 80% 1 year after infection in San Francisco).