AIDS was first described as a new and distinct clinical entity during 1981. Within a brief period of time, the notion that AIDS was some form of "gay plague" was quickly extinguished. The disease was suddenly being reported in other populations, such as intravenous (IV) drug users, blood transfusion patients, and hemophiliacs. IV drug users are the second-highest risk group for HIV and AIDS. The transmission of HIV among IV drug users is the result of needle-sharing practices, combined with the presence of cofactors such as behavioral practices. Among some sociodemographic groups, IV drug use is the primary risk factor for AIDS. IV drug users also represent a population that appears difficult to impact with routine AIDS prevention messages. Since arrest is the entry point to the criminal justice system, police officers in areas where drug use rates are high have the potential for dealing with HIV-infected suspects. AIDS has also become a special problem in contemporary jail and prison settings. In this respect, recommendations for quality medical care for inmates, proactive identification, and provision of condoms were made. 2 tables, 1 figure, 14 notes, 58 references.