Factors associated with PrEP use among sex workers: a cross-sectional study from female, male, and transgender sex workers in seven Thailand provinces

Background
Pre-exposure prophylaxis (PrEP) is a key strategy for HIV prevention in Thailand. National PrEP policy (2021) identifies priority populations; however, sex workers are not included, despite meeting established criteria for populations at substantial risk of HIV infection. PrEP uptake coverage among sex workers is very low – >7.5% coverage of all sex workers – and especially low among female sex workers. This study investigates key characteristics of PrEP non-users; that is, someone who has never initiated PrEP, among female, male and transgender sex workers to inform more inclusive and impactful PrEP policy and programming.

Methods
A cross-sectional study was conducted from September to December 2023 across seven high-HIV burden provinces (Bangkok, Chiang Mai, Chonburi, Kanchanaburi, Phuket, Sa Kaeo and Udonthani). We surveyed 1511 Thai female, male and transgender women aged ≥18 years, engaged in sex work (venue-based, non-venue based and online) in the past 3 months, reporting an HIV-negative or unknown HIV status. Structured questionnaires were used and data analyzed in Stata 15.1. Descriptive statistics summarized participant characteristics. Multivariate logistic regression identified factors independently associated with not using PrEP, estimating adjusted odds ratios with corresponding 95% confidence intervals.

Results
PrEP uptake was 1.3% among female sex workers (n = 621), 13.9% among male sex workers (n = 452) and 14.8% among transgender sex workers (n = 438). The majority (83.9%) had not used PrEP (n = 1268). PrEP awareness was lowest among female sex workers (27.7%). Those who had never used PrEP were significantly more likely to report PrEP concerns. Young sex workers (18–24 years) and those who had recently entered sex work reported behaviors putting them at higher risk of HIV exposure. High levels of interest in using PrEP were found among PrEP non-users, which increased further when long-acting injectable PrEP was proposed.

Conclusions
Tailored interventions to increase sex worker PrEP awareness, expanding options and addressing key concerns are needed for all sex worker populations. Specific programming is particularly needed for young, female and new entrant sex workers. Expanding PrEP options will increase PrEP demand and uptake among sex workers.