Examining the Effects of PrEP Use on Sexual Behaviors and Sexually Transmitted Infections Among Chinese Men who have Sex with Men: A Cross-Sectional Study

Abstract

Men who have sex with men (MSM) is a high-risk population for HIV and sexually transmitted infections (STIs). Pre-exposure prophylaxis (PrEP) is effective in HIV prevention. This study aims to examine the differences in sexual behaviors, STI prevalence and HIV/STI testing across subgroups of MSM with various PrEP use. Data were collected via a cross-sectional survey in an MSM community in Xi’an, Shaanxi, from 2022.01 to 2022.09. Participants were categorized as ‘PrEP-naïve and unwilling to use’, ‘PrEP-naïve but willing to use’, and ‘current or former PrEP users’. Shannon index was used to assess sexual act diversity and multivariate logistic regression analyzed factors associated with PrEP use. Of the 1,131 MSM participants, 23.52% were PrEP-naïve and unwilling, 64.98% were PrEP-naïve but willing, and 11.49% were current or former PrEP users. The PrEP-naïve but willing group had the highest recent STI testing rates at 73.06% and showed greater sexual act diversity (Shannon index 1.61). This group also had the highest syphilis rates (7.49% vs. 6.47% and2.54%, p < 0.01). Younger age (18–30: OR = 0.39 (0.18–0.85); 31–40: OR = 0.43 (0.20–0.96)) and lower education (high school/vocational: OR = 0.15 (0.04–0.58); associate degree: OR = 0.21 (0.06–0.71)) were factors that negatively influenced PrEP use. Current or former PrEP users had the highest oropharyngeal gonorrhea (14.39% vs. 9.68% and 5.80%, p < 0.01) and overall gonorrhea rates (20.86% vs. 17.17% and 8.37%, p < 0.001). ‘PrEP-naïve but willing’ participants consistently demonstrated high-risk sexual behavior, increased STI testing, and more diverse sexual acts, whereas PrEP users had the highest STI prevalence.