High HIV sexual risk behaviors and sexually transmitted disease prevalence among injection drug users in Northern Vietnam: implications for a generalized HIV epidemic.

BACKGROUND

HIV prevalence in Vietnam is currently concentrated among injection drug users (IDUs). The extent to which this core risk group represents a potential for broader HIV transmission to the general population is currently unknown.

METHODS

A community-based cross-sectional study among IDUs in Vietnam assessed sexually transmitted disease (STD) prevalence and behavioral risk factors. Qualitative interview data enhanced quantitative findings.

RESULTS

The prevalence of any STDs among 272 IDUs was 30% (chlamydia, 9%; herpes simplex virus type 2 [HSV-2], 22%; gonorrhea, 0%; and syphilis, 1%). Part-time work or unemployment (odds ratio [OR] = 2.74, 95% confidence interval [CI]: 1.1 to 6.9), sex with > or =2 sex workers in the past year (OR = 4.9, 95% CI: 1.91 to 12.6), having ever smoked heroin (OR = 4.5, 95% CI: 1.1 to 18.3), and injecting less frequently than daily (OR = 3.9, 95% CI: 1.43 to 10.6) were independently associated with chlamydial infection. Urban residency (OR = 4.0, 95% CI: 1.4 to 11.0) and daily injecting (OR = 2.2, 95% CI: 1.1 to 4.4) were independently associated with HSV-2. Odds of HSV-2 among older (> or =28 years of age) IDUs who had sex with <2 sex workers in the past year was higher than among younger IDUs who had sex with more sex workers (OR = 6.4, 95% CI: 2.1 to 18.4).

CONCLUSIONS

High STD prevalence and high-risk sexual and parenteral behaviors among IDUs indicate the potential for HIV/STD transmission to the general Vietnamese population.