NIDA technical review: nitrite inhalants.

Nitrite inhalants are commonly abused substances in the US and Europe. "Nitrite inhalants and AIDS" was a popular topic in the early 1980s when the cause of AIDS was not known. With the discovery of HIV, concern about nitrite use wained. However, nitrite inhalant use is associated with behavioral relapse and HIV transmission among gay men, with decreased lymphocyte counts and natural killer cell activity in laboratory studies, and remains a candidate "cofactor" in the pathogenesis of AIDS-related Karposi sarcoma. Discouraging nitrite use continues to be a worthwhile public health goal. Participants recommend specific research efforts.

Kaposi's sarcoma in patients with AIDS: sex, transmission mode, and race.

We review epidemiologic studies aimed at identifying the cause(s) or cofactors for AIDS-related Kaposi's sarcoma (KS). The epidemiology of AIDS-related KS in the United States differs from that of other forms of KS. One important feature of the epidemiology of AIDS-related KS is that its occurrence by race is strikingly disproportional. We believe this maldistribution can shed light on recent discussions concerning the cause of AIDS-related KS, and we propose further studies to elucidate the etiology of AIDS-related KS.

Kaposi's sarcoma. How can epidemiology help find the cause?

Kaposi's sarcoma (KS) remains the most commonly diagnosed cancer in AIDS patients. Neither the cause nor a cure for AIDS-related KS is known. KS serves as a striking example of how epidemiologists seek the cause of any disease. Epidemiologic analysis of reported KS cases is revealing but not definitive. The leading hypotheses for the cause of AIDS-related KS are an as-yet-unidentified sexually transmitted infectious agent and exposure to inhalant alkyl nitrites, often called poppers. Epidemiology suggests that persons can reduce their risk of KS by avoiding nitrite inhalants and changing behavior to reduce the risk of sexually transmitted infections.

Current CDC efforts to prevent and control human immunodeficiency virus infection and AIDS in the United States through information and education.

The human immunodeficiency virus (HIV) is estimated to have infected more than a million people in the United States and millions more in other countries. Even though there is no vaccine or effective treatment, HIV infection can be prevented through behavioral change. As the lead Public Health Service Agency for disease prevention, the Centers for Disease Control (CDC) has designed and implemented information and education activities with the ultimate goal of preventing HIV infection and AIDS in the United States. The target populations include the general public, school- and college-aged populations, persons infected or at increased risk of infection, minorities, and health workers. Because AIDS will be with us for a long time, CDC views educating the public as a long-term undertaking. The agency has initiated an intensive continuing national public information campaign, an informational brochure to be distributed to every U.S. household, a national AIDS information toll-free hotline, and a clearinghouse system that will maintain a comprehensive inventory of AIDS information resources and services. CDC also supports public information and education efforts by State and local health agencies. To reach school- and college-age youth, CDC, in consultation with governmental and national private sector organizations, developed guidelines for effective school health education to assist school health personnel in determining the scope and content of AIDS education. CDC also works with State and local education agencies to help carry out and evaluate educational efforts to prevent the spread of HIV among school- and college-age youth. The populations with the highest priority for AIDS information and education efforts are those who are at increased risk of acquiring or transmitting the AIDS virus because they use illicit intravenous drugs and share needles, engage in anal intercourse, have many sexual partners, practice prostitution, or engage in sex with those who practice these behaviors. Another high-priority population, because they can infect their offspring,is reproductive age women engaging in high-risk behavior and women infected with HIV who become pregnant. CDC programs targeted to these groups include community health education and risk reduction interventions, counseling and testing for HIV infection, AIDS community demonstration projects, perinatal AIDS prevention projects,and programs focused on preventing AIDS in minority populations. CDC is developing a variety of educational approaches for health workers in clinical settings because they are an important channel for providing accurate AIDS information, helping to assess risk, and counseling to actively reduce risk for the patient, sex partners of the patient, friends, and family members of the patient. CDC has conducted research and provided information and training on the use of HIV laboratory tests. CDC has also developed numerous scientific and technical guidelines and recommendations in consultation with practitioners, public health officials, and others and disseminated these through the Morbidity and Mortality Weekly Report. In addition,CDC has provided information about the risk of HIV transmission in the workplace and about methods of prevention. CDC will continue to evaluate these activities and support research in education and related interventions that may be necessary to prevent infection by the HIV virus. By providing educational support for behavior changes that decrease HIV transmission, we can contribute to AIDS prevention in the 1990s.

Measuring inhalant nitrite exposure in gay men: implications for elucidating the etiology of AIDS-related Kaposi's sarcoma.

We reviewed 12 epidemiologic studies conducted among gay men with AIDS to examine the role of potential 'cofactors' in the development of KS. Aspects of the studies reviewed include basic study design, wording of the questionnaires, and published results comparing KS patients with those who developed opportunistic infections indicative of AIDS. The studies included questions about sociodemographics, medical history, use of drugs, travel, and sexual behaviors. Patients were invited to provide blood and/or other specimens for laboratory analysis. The results of the review of epidemiologic studies are inconclusive. Nitrite inhalant use was a variable often associated with KS (five studies). The differences in outcomes of these studies may reflect differences in study designs, sample sizes, timing, quality, and content of interviews regarding nitrites, sexual behaviours and other potential cofactors. Epidemiologic study with careful consideration to content of questionnaires and laboratory testing may yet reveal the causes or cofactors for this tumor.

Epidemiology of the acquired immunodeficiency syndrome (AIDS).

PIP: This review of the epidemiology of acquired immunodeficiency syndrome (AIDS) focuses on the AIDS virus, immunology, clinical manifestations, surveillance, epidemiologic studies, and prevention. Although no treatment has been able to reverse the immunodeficiency characteristic of AIDS, epidemiologic studies have identified the routes of transmission of this virus and thus suggest strategies for prevention. The number of reported cases of AIDS in the US is increasing rapidly. The 1st 1000 cases were reported over 17 months, the next 2000 were accumulated over 12 months, and an additional 3000 were recorded in only 11 months. 5 groups of patients account for 93% of all AIDS cases: homosexual and bisexual men (73%), intravenous drug abusers (17%), hemophiliacs (1%), sexual contacts of these groups (1%), and transfusion recipients (1%). Opportunistic infections and cancers are not equally distributed among the different risk groups, leading to speculation that a cofactor such as cytomegalovirus infection or exposure to nitrate inhalants may predispose individuals with AIDS to develop Kaposi's sarcoma, for example. Epidemiology has contributed significantly to the understanding and control of AIDS. In addition, AIDS research has contributed to the field of epidemiology, pointing to the need for combined efforts of acute and chronic disease epidemiologists as well as coordination with other specialties. Studies of AIDS have also pointed to the need for further epidemiologic research on the health problems of homosexual men, intravenous drug abusere, hemophiliacs, and transfusion recipients.^ieng

Adverse virus-drug interactions.

Over the last 3 decades, epidemiologists and clinicians have identified a few clinical entities that appear to result when a viral infection and a chemical exposure overlap and interact. Ampicillin rash during infectious mononucleosis, Reye's syndrome following salicylate ingestion and certain viral infections, and the association of AIDS-related Kaposi's sarcoma with abuse of nitrite inhalants and infection due to human immunodeficiency virus are examples of such phenomena. Preclinical research provides additional evidence that viruses and chemicals may interact and produce illnesses in animals. We hypothesize that other virus-drug interactions may exist. Identifying such interactions may lead to a better understanding of the pathogenesis of currently baffling illnesses and may provide insights into ways of preventing and/or treating diseases that appear uncontrollable now.

Disease manifestation among homosexual men with acquired immunodeficiency syndrome: a possible role of nitrites in Kaposi's sarcoma.

To identify risk factors that determine the major manifestations of the acquired immunodeficiency syndrome (AIDS), the authors analyzed data from three epidemiologic studies conducted by the Centers for Disease Control. The authors compared patients by outcome of disease. Eighty-seven homosexual patients (47 with Kaposi's sarcoma, 20 with Pneumocystis carinii pneumonia, and 20 with both) had participated in the earlier studies, and their interviews and laboratory test results were available. Compared with patients who have Pneumocystis carinii pneumonia only, patients with Kaposi's sarcoma and those with both diseases reported more different sexual partners, more recreational drug use, higher incomes and higher rates of non-B hepatitis. Multivariate analysis showed that the variable most strongly associated with Kaposi's sarcoma was the use of large quantities of nitrite inhalants. A multifactorial model is postulated to explain the various disease manifestations of AIDS. This study suggests that the use of nitrite inhalants may be a cofactor in the development of Kaposi's sarcoma. By identifying other cofactors, investigators may be able to define additional opportunities for prevention of the development of AIDS.

The changing incidence of Kaposi's sarcoma among patients with AIDS.

Kaposi's sarcoma (KS), the most common cancer in patients with acquired immunodeficiency syndrome (AIDS), occurs predominantly in homosexual men. However, the percentage of homosexual AIDS patients with KS has declined during the past 6 years. This and other findings suggest that one or more cofactors associated with the homosexual lifestyle, rather than a special viral strain, probably influence the development of KS in patients infected with the human immunodeficiency virus (HIV). Possible reasons for the decline include changes in homosexual behaviors, leading to the practice of safer sexual techniques, and a decrease in use of nitrite inhalants. Identification of the KS-AIDS cofactor(s) could be invaluable to developing prevention and treatment strategies.

Bleeding injuries in professional football: estimating the risk for HIV transmission.

OBJECTIVE: To determine the risk for bleeding injuries in professional football and to estimate the risk for transmission of the human immunodeficiency virus (HIV) through such injuries. DESIGN: A prospective, observational study. PARTICIPANTS: Professional football players from 11 teams of the National Football League were observed during 155 regular season games from September through December 1992. MEASUREMENTS: The frequencies of bleeding injuries were calculated in association with environmental and athletic factors. Using this information, HIV prevalence, and data on transmission of HIV in other circumstances, the risk for transmission of HIV during football games was estimated. RESULTS: 575 bleeding injuries (average, 3.7 per game for each team) involving 538 players (average, 3.5 players on each team per game) were observed. Approximately 88% of the bleeding injuries were abrasions; the remainder were lacerations. Bleeding injuries were markedly more frequent during games played on artificial surfaces, during games played in domed stadiums, and on teams with a final win/loss percentage of 0.500 or lower. Using data on the prevalence of HIV among college men and rates of HIV transmission in the health care setting, the risk for HIV transmission to each player was estimated to be less than 1 per 85 million game contacts. CONCLUSIONS: Although injuries occur in professional football competitions, bleeding injuries, especially lacerations, occur infrequently. We estimate that the risk for HIV transmission during such competition is extremely remote. The role of artificial playing surfaces on the incidence or severity of bleeding injuries should be investigated.

Transmission of blood-borne pathogens during sports: risk and prevention.

Publicity about human immunodeficiency virus (HIV) infection in athletes has focused attention on the potential for transmission of blood-borne pathogens during sports and athletic competitions. Existing information suggests that the potential risk for such transmission is extremely low and that the principal risks athletes have for acquiring HIV and hepatitis B virus are related to off-the-field activities. Therefore, efforts to prevent transmission of blood-borne pathogens among athletes should emphasize prevention in off-the-field settings. We summarize technical and other information about this issue, and provide recommendations for the education of sports participants, for infection control in athletic settings, and for training of coaches and officials.

Contamination of the food chain by polychlorinated biphenyls from a broken transformer.

In 1979, widespread distribution of chicken and egg food products and grease contaminated with polychlorinated biphenyl (PCBs) occurred across the United States and as far away as Canada and Japan. The contamination was traced to an accidental leakage of PCBs from a transformer stored in a hog slaughtering plant in Montana. Breast milk analyses showed the PCB absorption had occurred among egg consumers. The episode illustrates the need for heightened vigilance over the fate of PCBs still in use.