Needle exchange programs (NEPs) consist of two components: (1) the collection and safe disposal of used syringes and (2) the provision of sterile syringes to individuals. NEPs were developed to prevent the spread of human immunodeficiency virus (HIV) and viral hepatitis (HBV and HCV) among injection drug users (IDUs), most of whom inject heroin, methampheta-mine, or cocaine. NEPs prevent the spread of HIV, HBV, and HCV by removing from circulation potentially contaminated syringes and replacing them with sterile syringes. Most NEPs also provide other disease prevention supplies, such as condoms; infectious disease testing and counseling; and access to other medical and social services, including substance abuse treatment. NEPs can operate in a variety of settings, including pharmacies, street and alley sites, mobile vans, substance abuse ...