Elevated HIV incidence rates among aboriginal participants in a cohort study of injection drug users in Vancouver, Canada
K J P Craib, P M Spittal, K Li, K Heath, N Laliberte, M Tyndall, M V O’Shaughnessy, M T Schechter
BC Centre for Excellence in HIV/AIDS, Vancouver, Canada
Objectives: To compare cumulative HIV incidence rates among aboriginal and non-aboriginal participants in a cohort of injection drug users (IDUs).
Methods: This analysis was based on 941 participants who were recruited between 05/96 and 12/00, HIV-negative at enrolment, and completed at least one follow-up visit. Cumulative incidence rates were calculated using Kaplan-Meier methods and compared via the log-rank test. Cox regression analysis using time-dependent covariates was used to identify independent predictors of time to HIV seroconversion.
Results: The mean duration of follow-up was similar between aboriginal and non-aboriginal participants (37 vs. 38 months; p=0.769). Aboriginal participants were significantly younger (33 vs. 35 years; p=0.017). As of 12/01, 44 of 230 aboriginal participants had seroconverted, compared to 68 of 711 non-aboriginals. After 44 months, the cumulative incidence rate was significantly higher among aboriginal participants (19.9% vs. 10.2%; p<0.001). Cumulative incidence was significantly higher among male aboriginals compared to male non-aboriginals (19.4% vs. 9.2%; p=0.007). Cumulative incidence was significantly higher among female aboriginal participants compared to female non-aboriginals (20.2% vs. 9.4%; p=0.007). Multivariate analysis of aboriginal participants revealed frequent injection of cocaine (ARR= 2.2; 95% CI: 1.1,4.2) and speedballs (ARR=2.5; 95% CI: 1.3, 5.0) to be independent predictors of time to HIV seroconversion. Among non-aboriginals, frequent cocaine injection (ARR=3.3; 95% CI: 1.9, 5.6), borrowing needles (ARR=1.8; 95% CI: 1.1, 3.1) and not being married (ARR=2.2; 95% CI: 1.0, 4.6) were independent predictors.
Conclusions: In the VIDUS cohort, HIV incidence was 95 percent higher among aboriginal participants. These findings have implications for indigenous populations worldwide. Harm reduction strategies addressing the HIV/AIDS concerns unique to this population are urgently required.
The XIV International AIDS Conference
Abstract no. MoPeC3537
“K J P Craib, et al. Elevated HIV incidence rates among aboriginal participants in a cohort study of injection drug users in Vancouver, Canada. Poster Exhibition: The XIV International AIDS Conference: Abstract no. MoPeC3537”