Incidence of HIV among injection drug users entering drug treatment programs in four US cities

We estimated seroincidence of human immunodeficiency virus (HIV) and preval ence of risk behaviors among injection drug users (IDUs) who accepted volun tary HIV resting on entry to drug treatment. Record-based incidence studies were conducted in 12 drug treatment programs in New York City (n = 890); N ewark, New Jersey (n = 521); Seattle, Washington (n = 1,256); and Los Angel es, California (n = 733). Records of confidential HIV tests were abstracted for information on demographics, drug use, and HIV test results. More deta iled data on risk behaviors were obtained by a standardized questionnaire. Although overall incidence rates were relatively low, in this population (< 1/100 person-years), there was a high prevalence of risk behaviors. Needle sharing was reported by more than one-third of the participants in each of the cities. HIV seroincidence rates were up to three-fold higher among youn ger ID Us. We found that HIV continued to be transmitted among ID Us who ha d received both drug treatment and HIV counseling and resting. HIV/AIDS (ac quired immunodeficiency syndrome) prevention education should continue to b e an important component of drug treatment.