AIDS in Africa: an epidemiologic paradigm.

Cases of the acquired immune deficiency syndrome (AIDS) have been reported in countries throughout the world. Initial surveillance studies in Central Africa suggest an annual incidence of AIDS of 550 to 1000 cases per million adults. The male to female ratio of cases is 1:1, with age- and sex-specific rates greater in females less than 30 years of age and greater in males over age 40. Clinically, AIDS in Africans is often characterized by a diarrhea-wasting syndrome, opportunistic infections, such as tuberculosis, cryptococcosis, and cryptosporidiosis, or disseminated Kaposi's sarcoma. From 1 to 18% of healthy blood donors and pregnant women and as many as 27 to 88% of female prostitutes have antibodies to human immunodeficiency virus (HIV). The present annual incidence of infection is approximately 0.75% among the general population of Central and East Africa. The disease is transmitted predominantly by heterosexual activity, parenteral exposure to blood transfusions and unsterilized needles, and perinatally from infected mothers to their newborns, and will continue to spread rapidly where economic and cultural factors favor these modes of transmission. Prevention and control of HIV infection through educational programs and blood bank screening should be an immediate public health priority for all African countries.

Epidemiology of HIV infection and AIDS in the United States.

By the end of 1987, nearly 50,000 cases of acquired immunodeficiency syndrome (AIDS) had been reported since 1981, 20,745 in the past year alone. Black and Hispanic adults and children have reported rates 3 to 12 times as high as whites. This can be largely attributed to higher reported rates in black and Hispanic intravenous (IV) drug abusers, their sex partners, and infants. In 1986, reported AIDS deaths increased adult male and female mortality in the United States by an estimated 0.7 and 0.07%, respectively, with much greater increases in selected age groups or areas of the country. The greatest variation in infection with the human immunodeficiency virus (HIV) (0 to 70%) has been found in surveys of IV drug abusers, while surveys of homosexual men reveal infection rates of 20 to 50%. Infection with HIV ranged from 0 to 2.6% in limited sexually transmitted disease clinic surveys of heterosexual men and women without a history of IV drug abuse or known sexual contact with persons at increased risk. The modes of HIV transmission are now well understood, but a large amount of biologic variability in efficiency of transmission remains to be explained. The period between initial infection with HIV and the development of AIDS is variable, but the risk for disease progression increases with duration of infection.

The epidemiology of AIDS: current status and future prospects.

The reported incidence of acquired immune deficiency syndrome (AIDS) continues to increase in countries throughout the world. On the basis of a polynomial model for extrapolation, the cumulative number of cases diagnosed and reported since 1981 in the United States is expected to double during the next year with over 12,000 additional cases projected to be diagnosed by July 1986. The annual incidence rates for single (never-married) men in Manhattan and San Francisco, intravenous drug users in New York City and New Jersey, and persons with hemophilia A ranged from 261 to 350 per 100,000 population during 1984. For single men aged 25 to 44 years in Manhattan and San Francisco, AIDS was the leading cause of premature mortality in 1984 as measured by years of potential life lost. Infection with HTLV-III/LAV is considerably more common than reported AIDS in high-risk populations and can persist at least for several years, so the presence of specific antibody should be considered presumptive evidence of current infection. The screening of donated blood and plasma for antibody to HTLV-III/LAV and use of safer clotting factor concentrates should greatly reduce HTLV-III/LAV transmission through blood and blood products. Most HTLV-III/LAV infections occur through sexual transmission, use of contaminated needles, and as a result of infected mothers passing the virus to newborns. Continued research commitment is needed to develop an HTLV-III/LAV vaccine and therapy for this infection. In the interim, widespread community efforts are needed to minimize transmission.

Transfusion-associated AIDS: serologic evidence of human T-cell leukemia virus infection of donors.

An assay for antibodies to membrane antigens of cells infected by human T-cell leukemia virus was used to examine serum from persons who donated blood to 12 patients with acquired immunodeficiency syndrome (AIDS) associated with blood transfusions. The occurrence of positive results in the assay was significantly greater among donors to the AIDS patients (9 of 117; 7.7 percent) than among random donors (1 of 298; 0.3 percent). Of 12 sets of donors examined, 9 sets included a donor whose serum gave positive results for the presence of the antibodies. In six of these nine sets, the seropositive donor was an individual who was also identified as a possible source of AIDS transmission when epidemiologic and immunologic criteria were used.

Epidemiological trends of AIDS in the United States.

The incidence of acquired immunodeficiency syndrome (AIDS) in the United States has increased rapidly since the first reports in 1981. Highest estimated rates are among single (never-married) men in Manhattan and San Francisco, men and women who have abused drugs intravenously, and persons with hemophilia. Serosurveys among populations at increased risk for AIDS have demonstrated a high prevalence of antibody to human T-cell leukemia virus III-lymphadenopathy-associated virus (HTLV-III/LAV), the virus which causes AIDS. The discovery of the virus and the widespread availability of serological tests greatly increase the ability to understand AIDS and to study the natural history of HTLV-III/LAV infection.

Opportunistic diseases reported in AIDS patients: frequencies, associations, and trends.

To look for associations and trends in the reported frequencies of particular opportunistic diseases in AIDS patients, we analyzed diseases in the 30,632 AIDS patients in the United States reported to the Centers for Disease Control (CDC) by 9 February 1987. Compared with all other AIDS patients, children were three times more likely to have cytomegalovirus disease, homosexual men were seven times more likely to have Kaposi's sarcoma, and Haitian-born patients were six, 14 and 13 times more likely to have toxoplasmosis, tuberculosis, and chronic enteric isosporiasis, respectively. The proportions of patients initially presenting with particular diseases have changed; from before 1983 to 1986, the proportion with Pneumocystis pneumonia climbed from 41.9 to 63.6% and the proportion with extrapulmonary cryptococcosis rose from 4.5 to 6.2%, while Kaposi's sarcoma fell from 30.9 to 14.2%, chronic herpes simplex declined from 4.2 to 2.1%, and toxoplasmosis of the brain dropped from 3.5 to 1.5%.

HIV infection and associated risk factors in female prostitutes in Kinshasa, Zaire.

In Africa, female prostitutes represent a high risk group for HIV infection. In Kinshasa, Zaire, 101 (27%) out of 377 prostitutes were seropositive to HIV by ELISA and Western blot determination. Seropositivity was significantly associated with the number of lifetime partners with a median number of 600 partners, four seropositives and 338 for seronegative individuals (P = 0.02). Seropositivity was also significantly associated with a history of taking oral medications for the prevention of sexually transmitted diseases and/or pregnancy (odds ratio = 2.21, confidence interval = 1.2-4.2), and with the introduction of any product into the vagina for hygiene or other purposes (odds ratio = 2.3, confidence interval = 1.1-4.7). In addition, among 85 prostitutes reporting condom use by their sexual partners during the previous year, the use of condoms by 50% or more of partners was associated with a reduced risk of HIV seropositivity (P = 0.046). An increased risk of HIV seropositivity was not associated with fellatio, anal intercourse, or with any type of kissing. Twenty-nine per cent of prostitutes reported at least one symptom suggestive of HIV infection, and seropositivity was associated with weight loss, either with or without chronic diarrhea or pruritic dermatitis. These data confirm that African prostitutes are at high risk for HIV infection and that the number of lifetime sexual partners, and factors which interfere with the integrity of the vaginal or cervical mucosa, may be associated with an increased risk of HIV infection acquired through heterosexual contact.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute HIV illness following blood transfusion in three African children.

Three children are described in whom pre-transfusion samples were HIV-seronegative and post-transfusional samples, obtained within 1 week after transfusion, were HIV-seropositive. Two of them developed a transient fever within 1 week of receiving the blood transfusion, and a transient generalized skin eruption which lasted for about 2 weeks. All three developed persistent generalized lymphadenopathy. One child developed a lumbar herpes zoster 7 months after transfusion. IgM Western blots demonstrated the presence of antibodies to protein bands p17, p24 and p55 in all three children. These three case reports suggest that children who receive a seropositive blood transfusion are at high risk for developing acute manifestations of HIV infection.

The projected incidence of AIDS and estimated prevalence of HIV infection in the United States.

Planning for health and social services and for prevention programs requires predicting the number of AIDS cases likely to be diagnosed during the next several years and estimating the prevalence of HIV infection. Extrapolating from recent AIDS incidence data, we estimate that 365,000 AIDS cases will be diagnosed in the United States through 1992 (68% prediction interval, 205,000 to 440,000). Both recent HIV seroprevalence surveys and historical AIDS incidence are consistent with the U.S. Public Health Service estimate that 1.0 to 1.5 million persons in the United States are now infected with human immunodeficiency virus (HIV). Although current estimates of future AIDS cases and of current prevalence of HIV infection are somewhat uncertain, better statistical estimation procedures are being developed, and current surveys will provide additional data on HIV prevalence in the United States within the next several years.

Acquired immune deficiency syndrome (AIDS) trends in the United States, 1978-1982.

This report summarizes results of surveillance for the acquired immune deficiency syndrome (AIDS) in the United States by the Centers for Disease Control through the first quarter of 1983. Surveillance has been predominantly passive, supplemented by active follow-up of requests to the Centers for Disease Control for pentamidine isethionate for treatment of Pneumocystis carinii pneumonia. The 1,299 reported cases showed trends of increasing incidence among all risk groups: homosexual men (72 percent), intravenous drug abusers (17 percent), persons of Haitian origin (5 percent), persons with hemophilia (1 percent), and others (6 percent). Cases were reported among residents of 35 states and the District of Columbia, with the majority from New York (49 percent) and California (22 percent). Of the 6 percent of patients without well-established risk factors for AIDS, many have suspected risk factors (e.g., blood transfusion or a sexual partner in a high-risk group).

Epidemiology of human immunodeficiency virus infection and acquired immunodeficiency syndrome.

As of December 31, 1988, 82,764 cases of acquired immunodeficiency syndrome (AIDS) and more than 46,000 AIDS-related deaths had been reported in the United States. In 1987, AIDS deaths accounted for 9% of the total mortality among men 25 to 34 years of age. Projections suggest that the impact of human immunodeficiency virus (HIV) infection on morbidity and mortality in young adults and children will continue to increase, with an estimated 50,000 cases projected to be diagnosed in 1989. The mean latency period between infection and diagnosis of AIDS is estimated to be more than seven years, and 78% to 100% of persons infected with HIV are predicted to develop AIDS within 15 years of onset of infection. Rates of seroconversions have been decreasing since 1984 among cohorts of homosexual HIV-seronegative men, and the proportion of AIDS cases among homosexual men is decreasing. In contrast, the proportion of AIDS cases attributed to intravenous drug use is increasing, with 33% of AIDS cases reported in 1988 occurring among intravenous drug users, their sex partners, or children of women who are intravenous drug users or sex partners of intravenous drug users. Worldwide, the differences in the epidemiology of HIV infection and AIDS are primarily due to differences in the proportions of the modes of transmission and in the time in which HIV infection was introduced.

Cluster of cases of the acquired immune deficiency syndrome. Patients linked by sexual contact.

The possibility that homosexual men with the acquired immune deficiency syndrome (AIDS) had been sexual partners of each other was studied. Of the first 19 homosexual male AIDS patients reported from southern California, names of sexual partners were obtained for 13. Nine of the 13 patients had sexual contact with one or more AIDS patients within five years of the onset of symptoms. Four of the patients from southern California had contact with a non-Californian AIDS patient, who was also the sexual partner of four AIDS patients from New York City. Ultimately, 40 patients in 10 cities were linked by sexual contact. On the basis of six pairs of patients, a mean latency period of 10.5 months (range seven to 14 months) is estimated between sexual contact and symptom onset. The finding of a cluster of AIDS patients linked by sexual contact is consistent with the hypothesis that AIDS is caused by an infectious agent.

Female gonorrhea: its relation to abnormal uterine bleeding, urinary tract symptoms, and cervicitis.

Data are presented from an investigation of the assocation of presenting complaints with gonococcal infection in females seeking primary care in an urban emergency room. Over 27% of patients in the study had cultures positive for Neisseria gonorrhoeae (GC). The GC positivity rates which were significantly higher than expected were found in patients with abnormal uterine bleeding, urinary tract symptoms, and cervicitis, as well as acute PID. Clinical findings suggest an etiologic role for the gonococcus in the pathogenesis of these disorders. Where the incidence of gonorrhea is high, new approaches in the managment of patients with these presenting complaints are necessary in order to prevent the more serious complications of gonorrhea and further spread of the disease.

The challenge of human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) in women and children.

PIP: Physicians in the field of reproductive health care have a special interest in reducing the incidence of human immunodeficiency virus (HIV) infection in women and their offspring. The majority of women with acquired immunodeficiency syndrome (AIDS) acquired infection through needle sharing. Sexual transmission of HIV appears to be less effective than transmission of other sexually transmitted diseases. The risk of male-to-female transmission from an infected partner has been estimated at 7-21%. The risk of perinatal transmission from the infected mother to her infant is far higher, however--at least 65%. There is also evidence that the immunosuppression of pregnancy may accelerate progression to AIDS in asymptomatic HIV carriers. In the absence of a vaccine or effective treatment, prevention of AIDS requires education about safe behaviors. A sizable decrease in the rate of transmission of HIV could occur if persons considered whether their partner might be infected before initiating sexual contact. Prevention of pediatric AIDS depends on the prevention of infection in women and the prevention of transmission from infected women. Women infected with HIV should be advised to avoid pregnancy and given highest priority for family planning services. Since many infected women are asymptomatic, HIV antibody testing is the only reliable way to determine whether a woman is actually infected. Such testing, however, should be limited to women believed at risk of HIV infection. Prenatal testing, if done early, can allow more options in the management of pregnancy, yet studies have found that women with positive HIV antibody tests do not elect to terminate their pregnancies at a higher rate than women whose test results are negative.^ieng

The acquired immunodeficiency syndrome: epidemiology and risk factors for transmission.

The acquired immunodeficiency syndromE (AIDS) is a very serious illness caused by a human T-lymphotropic retrovirus: human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). It primarily affects young adults living in one of several major metropolitan areas. Most patients are homosexual men, but heterosexual men and women have also been affected. Heterosexual men and women who use intravenous drugs, who are hemophiliacs, or who are sex partners of AIDS patients appear to be at increased risk for developing the disease.

Communicating surveillance, epidemiologic, and laboratory information on HIV infection and AIDS.

As the epidemic of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) has evolved over the past 10 years, the Centers for Disease Control (CDC) has been at the forefront of the scientific efforts that have characterized HIV-AIDS research. Because of CDC's central role in these efforts, the medical and public health communities have come to depend on the agency for prompt reporting of new developments related to the epidemiology of HIV infection and AIDS and for advice on risk management, prevention, and control. CDC disseminates this information through epidemiologic updates and prevention guidelines published in the periodical, Morbidity and Mortality Weekly Report, through articles in scientific journals and summary tabulations of AIDS case data and HIV seroprevalence data, and through interviews and presentations at scientific meetings. These formal information dissemination activities are supplemented with training and support efforts directed at health care providers, health department and laboratory personnel, educators, and centralized HIV-AIDS information resources. As questions are answered, controversies resolved, and new research applications explored, CDC will continue to provide the medical and public health communities with the most recent epidemiologic information and recommendations developed to help direct efforts in HIV prevention and risk reduction.

Monitoring the levels and trends of HIV infection: the Public Health Service's HIV surveillance program.

A comprehensive, multifaceted approach to HIV surveillance is needed to provide the information necessary for public health management and policy. Because HIV infection is not readily or uniformly ascertained, survey methods and sentinel surveillance approaches must be used. At least some of the surveys must be blinded, that is, anonymous and unlinked to identifiable persons, to avoid the uninterpretable impact of self-selection bias that could lead to both significant underestimates and occasional overestimates of HIV prevalence. Other surveys must be nonblinded, with careful interviews of volunteer participants to evaluate risk factors for HIV infection. These various surveys must continue over time to evaluate trends in infection. A comprehensive family of complementary HIV surveys and studies and a national household-based HIV seroprevalence survey have been undertaken by the Public Health Service in collaboration with other Federal agencies, State and local health departments, blood collection agencies, and medical research institutions. These projects focus on accessible segments of the general population, childbearing women, persons at high risk for HIV, and persons in special settings such as prisons and colleges. This comprehensive surveillance approach will help monitor the levels and trends of HIV infection in the United States and help prioritize, target, and evaluate HIV prevention activities.

The family of HIV seroprevalence surveys: objectives, methods, and uses of sentinel surveillance for HIV in the United States.

During 1987-89, the Centers for Disease Control (CDC), in collaboration with State and local health departments, other Federal agencies, blood collection agencies, and medical research institutions, implemented a national sentinel surveillance system for human immunodeficiency virus (HIV) infection. This ongoing surveillance system, known as the CDC family of HIV seroprevalence surveys, uses standardized survey and HIV serologic testing procedures in a group of sentinel populations from geographically diverse metropolitan areas, States, and Territories of the United States. As of September 1989, sentinel surveillance for HIV infection was being conducted in 41 States, Puerto Rico, and 39 metropolitan areas, including the District of Columbia. Information from this system complements AIDS surveillance data to assist health officials to direct resources and develop strategies for HIV prevention and health-care programs.

Review of death certificates to assess completeness of AIDS case reporting.

To assess the level of reporting of acquired immunodeficiency syndrome (AIDS) cases, the authors reviewed death certificates for periods of 3 months during July through December 1985 in each of four cities: Washington, DC, New York City, Boston, and Chicago. Since reporting began in 1981, these cities have reported 38 percent of all AIDS cases in the United States. Death certificates were selected and matched to the AIDS surveillance registries in each city, and medical records of those not on the AIDS registry were reviewed to determine if AIDS had been diagnosed. The estimated completeness of AIDS case reporting to AIDS surveillance systems was high in all four cities (ranging from 83 percent to 100 percent). The unreported cases were similar to reported cases with respect to sex, race, risk factor, and specific diagnosis. Of the causes of death examined, AIDS, Pneumocystis carinii pneumonia, and Kaposi's sarcoma were predictive of AIDS as defined by the CDC case definition. However, 77 of 588 deaths (13 percent) attributed to 1 of these 3 causes occurred in cases that were presumptively AIDS but did not meet the diagnostic requirements to be classified as AIDS for reporting purposes. A review of death certificates provides an easy and rapid means of evaluating surveillance efforts and can be a useful adjunct to other methods of surveillance for AIDS.

An overview of the effectiveness and efficiency of HIV prevention programs.

Because of the enormity of the HIV-AIDS epidemic and the urgency for preventing transmission, HIV prevention programs are a high priority for careful and timely evaluations. Information on program effectiveness and efficiency is needed for decision-making about future HIV prevention priorities. General characteristics of successful HIV prevention programs, programs empirically evaluated and found to change (or not change) high-risk behaviors or in need of further empirical study, and economic evaluations of certain programs are described and summarized with attention limited to programs that have a behavioral basis. HIV prevention programs have an impact on averting or reducing risk behaviors, particularly when they are delivered with sufficient resources, intensity, and cultural competency and are based on a firm foundation of behavioral and social science theory and past research. Economic evaluations have found that some of these behaviorally based programs yield net economic benefits to society, and others are likely cost-effective (even if not cost-saving) relative to other health programs. Still, specific improvements should be made in certain HIV prevention programs.