Chlamydia trachomatis infections among men who have sex with men and transgender women attending four community-based clinics in Thailand, 2019–2021

Abstract

Background: Chlamydia trachomatis (CT) infections are prevalent and often asymptomatic. Point-of-Care (PoC) tests offer a diagnostic option. We described the incidence and predictors of CT infection using secondary data collected from men who have sex with men (MSM) and transgender women (TGW) attending Community-Based Organizations (CBOs) clinics in Thailand. Methods: MSM and TGW aged ≥18 and had HIV risks were enrolled and followed for 12 months with visits every 3 months. Behavioral risks and Sexually Transmitted Infection testing were assessed at every visits. Specimens were collected via pharyngeal swab, urine sample, rectal swab, and neovaginal swab for TGW. These specimens were tested for CT using PoC test. The incidence was calculated using survival analysis, and the Cox regression model for multiple failures. Results: From 2019–2021, 1886 participants were enrolled. Of these, 89.7% were MSM; 10.3% were TGW: 20.7% were lost to follow-up. Of the remaining participants, 18.2% had CT at baseline, with 36.4% experiencing repeat infections. The incidence rate of CT was 42.9 infections per 100 person-years. Predictors of CT infections included enrollment year, age 18–24 years, HIV status, pre-exposure prophylaxis and condom use. Conclusion: Repeat CT infections were common. CBOs should incorporate POC STI testing into services, and the provision of STI prevention strategies.