Risk factors for HIV-1 seroconversion among injection drug users: a case-control study

Abstract

Objectives: A nested case-control study was conducted in Miami, Fla, to determine risk factors associated with human immunodeficiency virus type 1 (HIV-1) seroconversion among injection drug users.

Methods: The study identified 21 incident cases of HIV-1 infection and 76 unmatched controls from two longitudinal cohorts of injection drug users. One cohort consisted of individuals who originally had been recruited from treatment centers; a second cohort was recruited from the "street." Logistic regression analyses that adjusted for age, gender, and race were performed.

Results: The final model determined that the primary independent risk factor that best explained the risk for seroconversion was sharing injection equipment in the year prior to conversion; a marginal risk factor was presence of sexually transmitted disease during this same period.

Conclusions: Both an injection component and a sexual component play a role in seroconversion among injection drug users, although the injection component is much stronger.