Intravenous drug abusers and the acquired immunodeficiency syndrome (AIDS). Demographic, drug use, and needle-sharing patterns.

We studied the demographic characteristics, drug use patterns, and sexual habits of intravenous (IV) drug abusers to further define this population at risk for acquired immunodeficiency syndrome (AIDS). Sixteen IV drug abuser patients with AIDS, 24 IV drug abuser patients with AIDS-related complex (ARC), and 14 IV drug abuser controls without evidence of AIDS or ARC were evaluated. The subjects in each group were similar demographically, in drug use practice, and in sexual orientation and experience. Of the AIDS and ARC patients, 34 (88%) of 40, including all seven homosexual men, shared needles, as did all drug abusers without AIDS or ARC. Seventy-four percent of patients, including all homosexual men, attended "shooting galleries," where anonymous multiple-partner needle sharing took place. Needle sharing supports the hypothesis of AIDS transmission by a blood-borne route, can explain the spread of AIDS and the high rate of seropositivity to the putative AIDS agent among IV drug abusers, and is a logical link between IV drug abusers and male homosexuals, the two largest groups with AIDS.