Effect of HCV and HIV on mortality among injecting drug users

Jason Grebely and co-workers from CHASE (a cohort study of Vancouver inner city residents recruited from January 2003 to June 2004) presented mortality data from this cohort.

The investigators found, of 2069 participants identified, 721 were both HCV and HIV-negative (HCV/HIV), 962 were HCV-positive and HIV-negative (HCV+/HIV), 33 were HCV negative and HIV-positive (HCV/HIV+), and 353 were HCV and HIV-positive (HCV+/HIV+).

Among the 82 reported deaths, they found common causes of death were HIV (25.6%) and unnatural causes (19.5%). The natural cause mortality rate was 15.5 deaths/1000 person-years overall (n = 66), 9.6 deaths/1000 person-years for HCV/HIV (n = 15), 11.0 deaths/1000 person-years for HCV+/HIV (n = 28), 30.4 deaths/1000 person-years for HCV/HIV+ (n = 2), and 37.8 deaths/1000 person-years for HCV+/HIV+ subjects (n = 37).

For HCV/HIV+ and HCV+/HIV subjects, mortality attributed to HIV and HCV was 15.2 and 2.0 deaths/1000 person-years. In HCV+/HIV+ subjects, mortality attributed to HIV and HCV were 25.6 and 1.3 deaths/1000 person-years. Overall, natural cause mortality was associated with HIV infection (adjusted HR 5.3, 3.0 to 9.7, p<0.001), age (HR 1.8/10-year increase, 1.3 to 2.4, p <0.001) and aboriginal ethnicity (HR 1.7, 0.96 to 3.0, p = 0.07), and not associated with HCV infection (HR 1.0, 0.50 to 2.0, p = 0.99).

The investigators concluded that mortality rates in IDUs were high in this analysis, and HIV infection gave a 5-fold increase in risk of mortality. They noted that due to the timing of the HCV epidemic in this population, there has been little impact of HCV on mortality to date. They wrote Without programmes to treat HCV in this group, we expect a significant increase in mortality attributable to HCV infection.

Grebely J, Raffa J, Conway B et al. Effect of hepatitis C virus and HIV infections on mortality among illicit drug users. 14th CROI, 2007, Los Angeles. Poster Abstract 922.