AIDS and Behavior, Vol. 8, No. 1, March 2004 ( C  2004) Sexual Risks Among Southern Thai Drug Injectors Pajongsil Perngmark, 1,2 David D. Celentano, 3,4 and Surinda Kawichai 3 Received Apr. 1, 2003; revised Sep. 18, 2003; accepted Sep. 22, 2003 Sexual risks for HIV transmission among injection drug users (IDUs) in Thailand are not well characterized. We surveyed 272 male IDUs about their background, sexual behaviors, and drug use at drug treatment clinics in southern Thailand. HIV seroprevalence was determined using enzyme immunoassay. Fifty-six percent of participants were sexually active, of whom 88% had sex mostly with a noninjecting regular partner (wife or steady girlfriend), reporting low rates (34%) of condom use. Among sexually active IDUs, 43% were HIV infected and only a few were aware of their HIV serostatus. Condom use was associated with history of HIV voluntary counseling and testing (VCT) and poor perceived health status in multivariate analysis. Unprotected sex with regular sexual partners is frequent among IDUs in southern Thailand, where most IDUs have not sought VCT services. AIDS prevention efforts should address access to VCT and condom promotion to sexually active couples to prevent sexual transmission of HIV. KEY WORDS: Sexual behavior; condom use; HIV voluntary counseling and testing (VCT); IDU; Thailand; HIV transmission. INTRODUCTION Thailand’s public health campaign to prevent the heterosexual transmission of HIV by promoting “100% condom use” and targeting “direct” (brothel- based) female sex workers and their male patrons has received international recognition since it was established in the early 1990s (Sittitrai and Brown, 1994). The program successfully raised awareness and led to a major shift in Thai male sexual norms—to using condoms at all times in commercial sex—and contributed to a significant decline in HIV and 1 Department of Public Health Nursing, Prince of Songkla University, Thailand. 2 Formerly Ph.D. candidate, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205. 3 Infectious Diseases Program, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205. 4 Correspondence should be directed to David D. Celentano, Sc.D., M.H.S., Professor and Director, Infectious Diseases Program, De- partment of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolf Street, Suite E-6008, Baltimore, Maryland 21205 (e-mail: dcelenta@jhsph.edu). sexually transmitted disease (STD) infections among young Thai men nationwide (Celentano et al., 1998; Hanenberg et al., 1994; Mastro and Limpakarnja- narat, 1995; Rojanapithayakorn and Hanenberg, 1996; Ungphakorn and Sittitrai, 1994). Less effort, however, has been directed toward HIV infection and risk/harm reduction in the injec- tion drug use (IDU) population (Brown et al., 1994; Phoolcharoen et al., 1998; World Bank, Thailand Office, 2000). After more than a decade, the Thai na- tional HIV serologic surveillance surveys have shown a steady high rate of HIV prevalence in the 30–50% range among IDUs throughout the country (Division of Epidemiology 2000; World Bank, Thailand Office, 2000). Disturbingly, HIV prevalence has continued to rise among IDUs in the southern region of Thai- land, increasing from 40% in 1995 to 57% in 2000 (Division of Epidemiology, 2000, 2001), and is now the highest prevalence in the country (Division of Epidemiology, 2001). Recently, the HIV prevalence was found to be 51% among southern Thai IDUs in drug treatment (Perngmark et al., 2003); two-thirds of the IDUs interviewed shared contaminated injection equipment and most were unaware of their HIV 63 1090-7165/04/0300-0063/0 C  2004 Plenum Publishing Corporation