Behavior associated with drug abuse is now the single largest factor in the spread of HIV infection in the United States. According to the Centers for Disease Control and Prevention (CDC) analysis of HIV surveillance data, of the 859,000 cumulative AIDS cases reported about 25 % were among injection drug users (IDUs). Needles used to inject drugs can transmit HIV when they are used by more than one person. Needles should never be shared, but if they are shared they should be thoroughly cleaned between uses. For injection drug users who cannot or will not stop injecting drugs, using sterile needles and syringes only once remains the safest, most effective approach for limiting HIV transmission.

Evidence suggests that drug abuse treatment can help prevent the spread of HIV/AIDS, especially when combined with prevention and community-based outreach programs for at-risk people. These efforts can reduce or eliminate drug use and drug-related HIV risk behaviors. According to a report in 1981 there was sharp criticism of the Bush Administration's drug control efforts, the National Commission on AIDS endorsed needle-exchange programs to reduce the spread of AIDS among drug users.