Impact of HIV infection on non-AIDS mortality among Italian injecting drug users

To estimate the excess mortality of injecting drug users (IDU) stratified by HIV serostatus compared with the general population in Italy. To compare total and cause-specific mortality in HIV-positive versus HIV-negative IDU, in order to identify possible HIV-related non-AIDS causes of death in this population.

All IDU attending two drug-treatment centres in Rome who underwent HIV testing between 1985 and 1991 were enrolled into a prospective study. The end-point of the study was death from any cause by 31 December 1991. Mortality rates were compared using age-adjusted standardized mortality ratios and person-time techniques.

Of the 2431 IDU, 1661 (68.3%) were HIV-seronegative and 82 seroconverted. Of 181 deaths, comprising 89 from AIDS and 92 from other causes, the mortality rate was 4.5 and 0.8 per 100 person-years in HIV-seropositives and HIV-seronegatives, respectively. For non-AIDS mortality in HIV-seropositives, the overall rate was 1.7 per 100 person-years. Deaths from overdose and endocarditis/embolus tended to be higher in HIV-seropositive than HIV-seronegative IDU, although there was no difference in the rate of deaths due to pneumonia by HIV serostatus.

These data are consistent with other studies demonstrating a higher frequency of mortality among HIV-seropositive IDU. The excess in overdose mortality among HIV-seropositives is disturbing and merits further investigation.