How Syringe Exchanges Work
"Syringe exchange programs (SEPs) provide free sterile syringes and collect used syringes from injection-drug users (IDUs) to reduce transmission of bloodborne pathogens, including human immunodeficiency virus (HIV), hepatitis B virus, and hepatitis C virus (HCV)."
"Syringe Exchange Programs - United States, 2008," Morbidity and Mortality Weekly Report (Atlanta, GA: US Centers for Disease Control, Nov. 19, 2010), Vol. 59, No. 45, p. 1488.