An evaluation of needle and syringe exchange in San Francisco
The sharing of contaminated injection paraphernalia is a major route for transmission of human immunodeficiency virus (HIV) in the United States (1, 2, 3) and is one of the principal means by which HIV infection has spread in Italy, Spain, and Thailand (1, 4). In the U.S., one quarter (24%) of the 310,780 AIDS cases diagnosed among adults and adolescents through June, 1993 occurred among heterosexual injection drug users (IDUs). An additional 3.5% (10,800) were adults whose sole risk factor was having a sexual partner who injected drugs. Over half (56.2%) of the pediatric AIDS cases diagnosed in the U.S. through June, 1993, were attributed to HIV transmission from mothers who injected drugs themselves or who engaged in sexual activity with injection drug users (5). It is estimated that there are 1.2 million IDUs in the United States, about 15% of whom are believed to be enrolled in drug treatment on any day (6). Successful prevention of further spread of HIV in this population is crucial to national infectious disease prevention objectives (7). An unknown number of Americans in these risk categories are infected with HIV.