HIGH MORTALITY AMONG HIV-INFECTED INJECTING DRUG-USERS WITHOUT AIDS DIAGNOSIS - IMPLICATIONS FOR HIV-INFECTION EPIDEMIC MODELERS

Objective: To quantify mortality without AIDS diagnosis (pre-AIDS death) among HIV-infected injecting drug users (IDU) and to compare it with that among homosexual men. Setting: Municipal Health Service in Amsterdam, The Netherlands. Design: HIV-infected participants of a cohort of homosexual men (recruited since 1984) and a cohort of IDU (recruited since 1985) were followed up to investigate the occurrence of AIDS and pre-AIDS death up to 1 October 1992. Both seroprevalent and seroconverted participants were included. Methods: Product-limit estimates of cumulative AIDS incidence and cumulative pre-AIDS mortality were calculated for a competing risks model. Results: Of 455 HIV-infected homosexual men, 127 developed AIDS and two died without a diagnosis of AIDS during follow-up; 31 out of 279 HIV-infected IDU were diagnosed with AIDS and 33 died without an AIDS diagnosis. After 6.5 years of follow-up an estimated 43.7% of the homosexual men had been diagnosed with AIDS and 0.7% had died without an AIDS diagnosis, while 32.7% of the IDU had been diagnosed with AIDS and 19.8% had died without an AIDS diagnosis. Conclusions: After 6.5 years of follow-up one-fifth of a group of HIV-infected IDU had died without being diagnosed with AIDS. This phenomenon seriously limits the number of HIV-infected IDU that may ever be diagnosed with AIDS and should be considered by HIV infection epidemic modellers. The new case definitions for AIDS will limit the number of recorded cases of pre-AIDS death.