Mortality among injection drug users in Chennai, India (2005-2008)

Injection drug users (IDUs) have estimated mortality rates over 10 times higher than the general population; much of this excess mortality is HIV-associated. Few mortality estimates among IDUs from developing countries, including India, exist.

IDUs (1158) were recruited in Chennai from April 2005 to May 2006; 293 were HIV positive. Information on deaths and causes was obtained through outreach workers and family/network members. Mortality rates and standardized mortality ratios were calculated; multivariate Poisson regression was used to identify predictors of mortality.

We observed 85 deaths over 1998 person-years (p-y) of follow-up [mortality rate (MR) 4.25 per 100 p-y; 95% confidence interval (CI) = 3.41-5.23]. The overall standardized mortality ratio was 11.1; for HIV-positive IDUs, the standardized mortality ratio was 23.9. Mortality risk among HIV-positive IDUs (MR: 8.88 per 100 p-y) was nearly three times that of negative IDUs (MR: 3.03 per 100 p-y) and increased with declining immune status (CD4 cells > 350: 5.44 per 100 p-y vs. CD4 cells < or = 200: 34.5 per 100 p-y). This association persisted after adjustment for confounders. The leading causes of mortality in both HIV negative and positive IDUs were overdose (n = 22), AIDS (n = 14), tuberculosis (n = 8) and accident/trauma (n = 9).

Substantial mortality was observed in this cohort with the highest rates among HIV-positive IDUs with CD4 counts of less than 350 cells/microl. Although, in these 2 years, non-AIDS deaths outnumbered 0002030-related deaths, the relative contribution of 0002030-associated mortality is likely to increase with advancing HIV disease progression. These data reinforce the need for interventions to reduce the harms associated with drug use and increase HAART access among IDUs in Chennai.