Patterns of HIV prevalence and HIV risk behaviors among injection drug users prior to and 24 months following implementation of cross-border HIV prevention interventions in northern Vietnam and southern China.

In 2002, we implemented a 4-year HIV prevention intervention for injection drug users (IDUs) in Lang Son Province, Vietnam, and Ning Ming County, Guangxi Province, China, a cross-border region seriously affected by inter-twined epidemics of heroin injection and HIV infection. The interventions involve peer education on HIV risk reduction and provision of new needles/syringes through direct distribution and pharmacy vouchers. We consider this to be a structural intervention in which risk reduction information and sterile injection equipment are diffused through the IDU populations and not limited to those who actually interact with peer educators. The evaluation of structural interventions poses complex methodological challenges. The evaluation of our interventions relies primarily on cross-sectional surveys (interviews and HIV testing) of samples of IDUs selected using a combination of targeted cluster and snowball methods. We consider this to be an appropriate, albeit imperfect, design given the study context. This paper presents analyses of data from the IDU surveys conducted just prior to implementation of the interventions and 24 months thereafter. The cross-border interventions have reached large proportions of the IDUs in the project sites, drug-related HIV risk behaviors have declined in frequency, and HIV prevalence among IDUs has been stable in China and declined in Vietnam over the 24 months since the interventions were implemented. Attribution of these positive trends to the interventions must be qualified in light of possible sampling biases and the absence of control groups. However, we believe that the structural interventions implemented by the cross-border project have played a role in stabilizing HIV prevalence among IDUs two years after they were initiated. Evidence of further diffusion of the interventions among IDUs and continued stability or decline of HIV prevalence would strengthen this case.

Correlates of HIV status among injection drug users in a border region of southern China and northern Vietnam.

This article presents an analysis of the correlates of HIV status among samples of injection drug users (IDUs) in Lang Son Province, Vietnam (n=348), and Ning Ming County, Guangxi Province, China (n=294), who were interviewed and tested for HIV antibody just before the start of a peer-based HIV prevention intervention in this border region. Participants were largely male, in their 20s, and single. Logistic regression analysis suggests that among Chinese IDUs, border-related factors (eg, living closer to the border, buying drugs across the border more frequently) and younger age are the best predictors of HIV positivity. In Vietnam, HIV status seems to drive behavior (eg, some risk reduction practices are predictive of HIV positivity). These differing patterns may reflect the fact that the intertwined epidemics of heroin injection and HIV began earlier and HIV prevalence has reached significantly higher levels in Lang Son than across the border in Ning Ming. Although border-related factors emerge as predictors in Ning Ming, more IDUs in Lang Son are HIV-positive and may be reacting behaviorally to that status. Their greater likelihood of engaging in risk reduction measures may reflect some combination of a belief that risk reduction can slow disease progression and an altruistic desire to avoid infecting others.