Incidence of HIV and sexually transmitted infections and risk factors for acquisition among young methamphetamine users in northern Thailand

Abstract

BACKGROUND:: Southeast Asia is experiencing an epidemic of methamphetamine use, a drug associated with risky sexual behaviors, putting a large segment of the population at increased risk for sexually transmitted infections (STIs) and HIV and in need of prevention efforts. Incidence estimates of STIs are rare in Southeast Asia, especially among newer risk groups. STUDY DESIGN:: We enrolled methamphetamine users aged 18 to 25 years in a 12-month randomized behavioral intervention trial in Chiang Mai, Thailand in 2005. Behavioral questionnaires were administered at visits every 3 months, and biologic specimens were collected at baseline and 12 months to test for common STIs (chlamydia, gonorrhea, HSV-2, and HIV). Poisson regression with robust variance was used to determine risk factors for incident STIs. RESULTS:: Overall, 12.7% of 519 participants acquired at least 1 STI. Chlamydia was the most common (10.6%), followed by HSV-2 (4.0%), gonorrhea (2.9%), and HIV (0.6%). Risk factors for both men and women included self-reported incarceration and having a casual sex partner during follow-up, and having a prevalent STI at baseline. Additionally, among women, having 2 or more heterosexual partners, and among men, having a greater frequency of drunkenness were risk factors for STI acquisition. CONCLUSIONS:: Although HIV incidence is low in this population, incidence of other STIs is high compared with previous studies of young Thai adults. Risk factors for acquisition emphasize the need for new prevention strategies targeted toward current populations at risk. Copyright © 2009 American Sexually Transmitted Diseases Association.