JMIR Publications

ABSTRACT

Background:

In China, unprotected sex among men who have sex with men (MSM) is the primary route of HIV infection among young people. Chengdu is a hotspot for reported HIV cases among young people nationwide. Extensive use of geosocial networking (GSN) smartphone apps has dramatically changed the pattern of sexual practice among young MSM (YMSM). However, data on HIV incidence and the risk practice of GSN app-using YMSM are still opaque.

Objective:

This study aims to analyze and understand the HIV incidence and its risk factors among gay GSN app-using YMSM in Chengdu.

Methods:

An open cohort study was conducted among 18-24 years old YMSM through a gay GSN smartphone app in Chengdu, China, from July 2018 to December 2020. Every participant completed an online questionnaire on sociodemographic characteristics, sexual behaviors, and other related status; made a reservation for HIV testing online, then tested at the designated offline testing site. At least one additional HIV test was taken via the app during the study period, and participants were evaluated at the end of the study, or at the time of HIV seroconversion. By dividing the sum of the observed HIV seroconversions by the observed person-years, HIV incidence was calculated and compared between the student and non-student MSM. Univariate and multivariate (cox proportional hazards regression) analyses were used to discuss the risk factors for HIV new infections.

Results:

In the cohort, 24 seroconversions occurred among 625 YMSM who took at least two HIV tests from app during the study period, contributing 505 observed person-years (PY). The HIV incidence rate were 4.75 [95% confidence interval (CI): 2.89-6.61]/100 PY, 3.60 (95%CI: 1.27-5.93)/100 PY, and 5.88 (95%CI: 2.97-8.79)/100 PY, among all MSM, student MSM and non-student MSM, respectively. In addition, the HIV incidence was 11.11 (95%CI: 4.49-17.73)/100 PY among those who had lived locally for 6 months or less, and 7.14 (95%CI: 1.52-12.77) /100 PY among those who had senior high school or less education. More than two sexual partners [adjusted hazard ratio (aHR) = 3.63, 95% CI: 1.08-12.23] in the preceding 6 months was a risk factor for HIV new infections. Those who reported consistent condom use for anal sex (aHR =0.38, 95% CI: 0.16-0.88) and insertive anal sex only (aHR = 0.10, 95% CI: 0.01-0.75) in the preceding 6 months were protective factors for new HIV infections.

Conclusions:

The rate of HIV new infection among YMSM who active in GSN smartphone app is high, especially among migrant non-student MSM. Targeted interventions on GSN smartphone app should be implemented to provide demand-adapted prevention and services to reduce the threat of HIV.