Editors' introduction: HIV and other infectious diseases among drug-involved offenders.

It has been a generation since Acquired Immune Deficiency Syndrome (AIDS) was first described as a new and distinct clinical entity. Although the origins of HIV, the virus that causes AIDS, remain unclear, the first reports in the United States occurred during the late spring and early summer of 1981. Many contemporary readers may not recall the initial accounts, and for others they are likely buried in history. But it is an intriguing story that warrants some brief recounting. First, clinical investigators in Los Angeles reported five cases to the Centers for Disease Control and Prevention (CDC) of Pneumocystis carinii pneumonia (PCP) among gay men. None of these patients had an underlying disease that might have been associated with PCP or a history of treatment for a compromised immune system. All, however, had other clinical manifestations and laboratory evidence of immunosuppression. Second, and within a month, 26 cases of Kaposi’s sarcoma (KS) were reported among gay men in New York and California. What was so unusual was that prior to these reports, the appearance of both afflictions in populations of previously healthy young men was unprecedented. PCP is an infection caused by the parasite P. carinii, previously seen almost exclusively in cancer and transplant patients receiving immunosuppressive drugs. KS, a tumor of the blood vessel walls that often appears as blue-violet to brownish skin blotches, had been quite rare in the United States, occurring primarily in elderly men, usually of Mediterranean origin. Furthermore, like PCP, KS had also been reported among organ transplant recipients and others receiving immunosuppressive therapy. This observation quickly led to the hypothesis that the increased occurrences of the two disorders in gay men were due to some underlying immune system dysfunction. This hypothesis was further supported by the incidence among gay men of numerous “opportunistic infections”—infections caused by microorganisms that rarely generate disease in persons with normal immune defense mechanisms. It is for this reason that the occurrence of KS, PCP, or other opportunistic infections in a person with unexplained immune dysfunction became known as the ”acquired immune deficiency syndrome,” or more simply, AIDS. With the recognition that the vast majority of the early cases of this new clinical syndrome involved gay and bisexual men, it seemed logical that the causes might be related to behaviors unique to that population. The sexual revolution of the 1960s and 1970s was accompanied not only by greater sexual permissiveness among both heterosexuals and gays, but also by a broader social acceptance of homosexuality. The emergence of commercial bathhouses and other outlets for sexual contacts among gay men further increased promiscuity, with certain segments of the gay population viewing promiscuity as a facet of “gay liberation.” In fact, among the early patients diagnosed with AIDS, their sexual recreation typically occurred within the anonymity of the bathhouses with similarly promiscuous men. And to complicate matters, sexually active gay men with multiple sex partners were manifesting high rates of sexually transmitted diseases—gonorrhea, syphilis, genital herpes, anal warts, and hepatitis B. Because of this situation, it is not surprising that such factors as frequent exposure to semen, rectal exposure to semen, the body’s exposure to amyl nitrate and butyl nitrate (better known as “poppers” and used to enhance sexual pleasure and performance), and a high prevalence of sexually transmitted diseases were themselves considered potential causes of AIDS. Yet while it was apparent that AIDS was a new disease, most of the gay lifestyle behaviors were not particularly new, having changed only in a relative sense. As such, it was difficult to immediately single out specific behaviors that might be related to the emerging epidemic. Within a brief period, however, the notion that AIDS was some form of “gay plague” was quickly extinguished. The disease was suddenly being reported in other populations, such as injection drug users, blood transfusion patients, and hemophiliacs. What these reports suggested to the scientific community was that an infectious etiology for AIDS had to be considered. This was corroborated when AIDS cases began to emerge among individuals who had been injected with blood or blood products but had no other expected risk factors, making the transmission vectors for the disease somewhat clearer. Such cases were confirmed first among people with hemophilia, followed by blood transfusion recipients and injection drug users who shared hypodermic needles, syringes, and other paraphernalia. Then, with the appearance of documented cases of AIDS among the heterosexual partners of male injection drug users, it became increasingly evident that AIDS was a disease transmitted by the exchange of certain bodily fluids, primarily blood, blood products, and semen. As such, sexual orientation was not a risk factor per se. In 1983 and 1984, scientists at the Institute Pasteur in Paris and the National Institutes of Health in the United States identified and isolated the cause of AIDS: Human T-cell Lymphotropic Virus, Type III (HTLV-III), or Lymph-adenopathy-Associated Virus (LAV). Later, this virus would be renamed human immunodeficiency virus, more commonly known as HIV.