Differentiating the incidence and burden of HIV by age among women who sell sex: a systematic review and meta-analysis

Introduction Young women who sell sex (YWSS) are at heightened risk of HIV acquisition and transmission and are among the least engaged in HIV services. There is insufficient epidemiologic evidence characterizing the burden of HIV among YWSS, particularly as compared to older WSS. These data are needed to design and tailor effective HIV prevention and treatment programmes for this population. Methods We conducted two parallel systematic reviews and meta-analyses to define both the immediate and long-term HIV risks for YWSS, including among women engaged in sex work, survival sex and transactional sex. In the first review, we identified and synthesized published studies of HIV incidence comparing estimates for cisgender women <= 24 years of age versus >24. In the second review, we identified and synthesized studies of HIV prevalence, comparing estimates for cisgender women who initiated selling sex <18 versus >= 18 years. In both reviews, we completed a search of four databases for articles in any language and any geographic area published from 1 January 1980 until 12 February 2021. Included articles were assessed for quality and a random effects model was used to calculate pooled effect estimates for each review. Results and Discussion We identified 12 studies for the HIV incidence review and 18 studies for the HIV prevalence review. In a meta-analysis, HIV incidence was elevated in younger (5.3 per 100 person-years [PY]; 95% confidence interval [CI]: 3.5, 7.1) compared to older women (2.8 per 100 PY; 95% CI: 1.7, 3.9), although CIs overlapped. HIV prevalence among those who initiated selling sex <18 years of age (28.8; 95% CI: 18.9, 38.7) was higher than those who initiated later (20.5; 95% CI: 12.4, 28.6). Conclusions These companion reviews offer an important perspective on the relative HIV risk of engaging in selling sex at a younger age. Our findings highlight the unique and intersectional challenges YWSS face, and the importance of ensuring that health services are tailored to meet their specific needs. Research and programming should routinely stratify data into meaningful age bands to differentiate and intervene within this population.