MAINTAINING LOW HIV SEROPREVALENCE IN POPULATIONS OF INJECTING DRUG-USERS

Objectives.-To describe prevention activities and risk behavior in cit ies where human immunodeficiency virus (HIV) was introduced into the l ocal population of injecting drug users (IDUs), but where seroprevalen ce has nevertheless remained low (<5%) during at least 5 years. Design and Setting.-A literature search identified five such cities: Glasgow , Scotland; Lund, Sweden; Sydney, New South Wales, Australia; Tacoma, Wash; and Toronto, Ontario, Case histories were prepared for each city , including data on prevention activities and current levels of risk b ehavior among IDUs. Participants.-Injecting drug users recruited from both drug treatment and nontreatment settings in each city. Interventi ons.-A variety of HIV prevention activities for IDUs had been implemen ted in each of the five cities. Results.-There were three common preve ntion components present in all five cities: (1) implementation of pre vention activities when HIV seroprevalence was still low, (2) provisio n of sterile injection equipment, and (3) community outreach to IDUs, Moderate levels of risk behavior continued with one third or more of t he IDUs reporting recent unsafe injections. Conclusions.-In low-seropr evalence areas, it appears possible to severely limit transmission of HIV among populations of IDUs, despite continuing risk behavior among a substantial proportion of the population. Pending further studies, t he common prevention components (beginning early, community outreach, and access to sterile injection equipment) should be implemented where ver populations of IDUs are at risk for rapid spread of HIV.