The completeness of AIDS surveillance.

AIDS surveillance data are widely used in setting HIV intervention policies, and the effectiveness of these data depend on their completeness. We reviewed studies conducted by state and local health departments on the completeness of AIDS reporting. These studies identified AIDS cases through alternate data sources, such as death certificates, hospital discharge records, disease registries, or medication records. In most instances greater than 80% of AIDS cases detected through these studies had been reported, although lower levels of reporting were found in some outpatient settings. A comparison of vital records and AIDS surveillance confirmed that AIDS surveillance is identifying 70-90% of all HIV-related deaths in men 25-44 years of age. Historically, AIDS surveillance has emphasized reporting from hospitals. Efforts to maintain current levels of reporting, or to improve reporting, are challenged by the growth of the epidemic and by the increasing role of outpatient diagnosis of AIDS.

Epidemiology of human immunodeficiency virus encephalopathy in the United States.

To investigate the epidemiology of human immunodeficiency virus (HIV) encephalopathy, we analyzed cases of acquired immunodeficiency syndrome (AIDS) reported to the Centers for Disease Control (CDC) from September 1, 1987, through August 31, 1991. Of 144,184 persons with AIDS (PWAs), 10,553 (7.3%) were reported to have HIV encephalopathy. The proportion of PWAs with HIV encephalopathy was highest at the extremes of age: in PWAs less than 15 years old the proportion was 13%, and in PWAs greater than or equal to 15 years old the proportion progressively increased with age, from 6% in PWAs 15 to 34 years old to 19% in PWAs greater than or equal to 75 years old (p = 0.00001, chi 2 test for linear trend in proportions). The reported annual incidence of HIV encephalopathy per 100,000 population aged 20 to 59 years was 1.4 in 1988, 1.5 in 1989, and 1.9 in 1990. This analysis best provides estimates for HIV encephalopathy as the initial manifestation of AIDS because the CDC AIDS reporting system often does not ascertain diagnoses after the initial AIDS report. These data suggest that age (very young or old) is associated with the development of HIV encephalopathy and that HIV encephalopathy is a common cause of dementia in adults less than 60 years old in the United States.

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.

Risk factors for infection with Echinococcus multilocularis in Alaska.

We studied 19 Eskimo patients with alveolar hydatid disease from the north-western coast of Alaska for risk factors for infection with Echinococcus multilocularis. Each case-patient was matched by age and sex with 2 unrelated controls who had no clinical or serologic evidence of infection with E. multilocularis and who resided in three villages endemic for alveolar hydatid disease. Behaviors thought to increase exposure to E. multilocularis and the chronologic occurrence of these behaviors in the participant's life were assessed by a standardized questionnaire. Case-patients were more likely than controls to have owned dogs for their entire lives (odds ratio 6.00, P less than 0.05), tethered their dogs near the house (odds ratio 8.50, P less than 0.05), and lived in houses built directly on the tundra rather than on gravel or a permanent foundation (odds ratio 11.00, P less than 0.01). Case-patients were not more likely to have owned sled dogs, trapped or skinned foxes, or engaged in other outdoor activities away from home. These findings suggest that controlling the parasite in the domestic dog population, as well as controlling the dog population itself, are important aspects of preventing alveolar hydatid disease in the northwestern Native Alaskan population.

Shedding of oocysts in immunocompetent individuals infected with Cryptosporidium.

In June 1985, we investigated an outbreak of cryptosporidiosis at a day-care center in Florida. Through day-care center-wide stool screening, 33% (28/84) of the children and 22% (4/18) of the staff members submitting stool specimens were found to have cryptosporidiosis. Children 12-35 months of age and their teachers were at highest risk. All but 1 of the Cryptosporidium-positive patients reported diarrhea, which lasted between 1-44 days. Serial stool specimens were obtained from 8 infected individuals (5 children and 3 adults). Duration of oocyst shedding ranged from 8 to more than 50 days and continued in 5 individuals after diarrhea ceased. No relationship was found between duration of oocyst shedding and the age of the patient or duration or severity of diarrhea. Results of the investigation indicate that infected individuals may continue to excrete oocysts and, therefore, may remain infectious for days or weeks after gastrointestinal symptoms disappear.

The epidemiology of Acanthamoeba keratitis in the United States.

We surveyed members of the Ocular Microbiology and Immunology Group and reviewed laboratory requests at the Centers for Disease Control to determine better the epidemiology of Acanthamoeba keratitis in the United States. A total of 208 cases of Acanthamoeba keratitis were identified. The number of cases increased gradually between 1981 and 1984, with a dramatic increase beginning in 1985. Males and females were equally affected. Of the 208 patients, 85 (41%) resided in California, Texas, Florida, or Pennsylvania. Of 189 patients, 160 (85%) wore contact lenses, predominantly daily-wear or extended-wear soft lenses. Of the 138 patients who wore contact lenses and for whom information was available, 88 (64%) used saline prepared by dissolving salt tablets in distilled water. Patients aged 50 years and older were more likely to have had a history of trauma than younger patients, and males were more likely to have a history of trauma than females.

Acquired immune deficiency syndrome associated with hemophilia in the United States.

Persons with hemophilia and other coagulation disorders were at risk for infection with HIV as a result of receiving blood products, particularly concentrated clotting factors. Because these products are now donor-screened and heat-treated to inactivate HIV, the risk of further infection in this population has been minimized. However, before the introduction of these interventions, many persons with hemophilia had been infected. As of Jan 4, 1988, 463 cases of hemophilia-associated AIDS had been reported to the Centers for Disease Control. Most patients had severe hemophilia and received commercially produced concentrated clotting factors. These patients may constitute as many as 25% of those hemophilic men known to be infected with HIV. Through heterosexual and perinatal transmission, the partners and offspring of persons with hemophilia can become infected with HIV. The seroprevalence rate for female sex partners of men with hemophilia may be as high as 21%, and 16 AIDS cases have already been reported. Counseling and public health interventions are needed to prevent the further spread of HIV infection in sex partners and offspring of these patients and to prevent the associated morbidity and fatalities. Because HIV infection can be transmitted by exposure to infected blood or blood components, health-care workers whose activities involve contact with infected blood or body fluids are also at risk for HIV infection. Prospective studies suggest this risk is very low; nevertheless, health-care workers need to adhere rigorously to infection-control precautions to minimize the risk of exposure to blood and body fluids. These precautions include wearing gloves, masks, protective eyewear, and gowns depending on the type of exposure anticipated.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of zoonotic diseases transmitted by pets on human health and the economy.

In the context of all causes of human morbidity and mortality, or even within the context of all infectious diseases affecting the public health, pet-associated zoonotic infections are of moderate importance. The data documented in Table 1, however, indicate that they do exact significant human health and economic costs. If complete data were available for all of the infections shown in Table 1, the costs would be considerably higher. Moreover, most of these diseases are preventable through educating the public, particularly pet owners, of the zoonotic potential of these diseases, so that they may take precautions to minimize the risks leading to infection. These measures include appropriate health care of pets to eliminate infectious agents, reducing the number of uncontrolled, ownerless pets as well as unwanted or poorly supervised pets, preventing pets from soiling public places with their feces, excluding animals from areas where children play, enforcing leash laws, and promoting responsible pet ownership. Veterinarians, physicians, and public health agencies can aid in these efforts; ultimately, however, the responsibility lies with the pet owner.

Tuberculosis in New Zealand, 1985-90.

AIM: to examine recent trends in tuberculosis in New Zealand. METHODS: histologically and bacteriologically confirmed cases of tuberculosis notified to area health boards from 1985 to 1990 were analysed. RESULTS: a total of 843 cases were reported during 1985-90 for an average annual incidence rate of 4.2 cases per 100,000 population; incidence rates for each year were similar. The incidence of tuberculosis was higher among males than females and increased with age. Maori were five times more likely to develop tuberculosis than Europeans, Pacific Islanders were 10 times more likely, and persons of other ethnic groups combined were 15 times more likely. From 1985 to 1990, the number of cases decreased among Europeans, remained stable among Maori and Pacific Islanders, and increased among persons of other ethnic origin. CONCLUSION: although the overall incidence of tuberculosis is relatively low, it continues to be a public health problem in New Zealand, particularly among Maori and immigrants from Asia and the Pacific Islands.

Waterborne outbreak of Campylobacter jejuni in Christchurch: the importance of a combined epidemiologic and microbiologic investigation.

Campylobacter is a common cause of gastroenteritis in New Zealand; however, the source of infection usually remains unknown. Reports of two cases of Campylobacter jejuni enteritis at a camp and convention centre near Christchurch were investigated. Through interviews of persons living at or attending the camp, 42 additional cases were identified. Epidemiologic and microbiologic data strongly suggested the water supply as the source of infection. The combined epidemiologic and microbiologic investigation was useful in quickly defining the magnitude and source of the outbreak, allowing for rapid implementation of control measures.

Trichinosis in Southeast Asian refugees in the United States.

Between 1975 and 1984, the incidence of trichinosis in the United States (per million person years at risk) was 25 times greater for the Southeast Asian refugee population than for the general United States population. Cases in the southeast Asian refugees differed from those reported previously in the general population in geographic distribution and source of infected meat. Cambodians and Laotians accounted for over 90 per cent of the cases in the Southeast Asian refugees, but comprised less than 50 per cent of that total population.

Epidemiology of free-living ameba infections.

Small free-living amebas belonging to the genera Acanthamoeba and Naegleria occur world-wide. They have been isolated from a variety of habitats including fresh water, thermal discharges of power plants, soil, sewage and also from the nose and throats of patients with respiratory illness as well as healthy persons. Although the true incidence of human infections with these amebas is not known, it is believed that as many as 200 cases of central nervous system infections due to these amebas have occurred worldwide. A majority (144) of these cases have been due to Naegleria fowleri which causes an acute, fulminating disease, primary amebic meningoencephalitis. The remaining 56 cases have been reported as due either to Acanthamoeba or some other free-living ameba which causes a subacute and/or chronic infection called granulomatous amebic encephalitis (GAE). Acanthamoeba, in addition to causing GAE, also causes nonfatal, but nevertheless painful, vision-threatening infections of the human cornea, Acanthamoeba keratitis. Infections due to Acanthamoeba have also been reported in a variety of animals. These observations, together with the fact that Acanthamoeba spp., Naegleria fowleri, and Hartmannella sp. can harbor pathogenic microorganisms such as Legionella and or mycobacteria indicate the public health importance of these amebas.

Potential effect of revising the CDC surveillance case definition for AIDS.

The Centers for Disease Control (CDC) revised the surveillance case definition for acquired immunodeficiency syndrome (AIDS) in August, 1987. To determine the impact of this revision, information was extracted from the medical charts of the 630 patients receiving comprehensive medical care as of 1980 at 6 haemophilia treatment centres, and who were therefore likely to have been infected with human immunodeficiency virus (HIV). 38 (6%) and 47 (7%) met the 1985 and 1987 case definitions, respectively (22% increase). Of the cases added by use of the 1987 case definition, 3 patients had HIV dementia, 3 had Pneumocystis carinii pneumonia (2 of whom were presumptively diagnosed and 1 who had been receiving steroids and immunosuppressives), and 3 had HIV wasting syndrome. These data suggest that the revision of the AIDS case definition will have a substantial impact on future AIDS surveillance trends in persons with haemophilia and perhaps in other risk groups.

PIP: The Centers for Disease Control (CDC) revised the surveillance case definition for Acquired immunodeficiency syndrome (AIDS) in August, 1987. To determine the impact of this revision, information was extracted from the medical charts of the 630 patients receiving comprehensive medical care as of 1980 at 6 hemophilia treatment centers, and who were therefore likely to have been infected with human immunodeficiency virus (HIV). 38 (6%) and 47 (7%) met the 1985 and 1987 case definitions, respectively (22% increase). Of the cases added by use of the 1987 case definition, 3 patients had HIV dementia, 3 had Pneumocystis carinii pneumonia (2 of whom were presumptively diagnosed and 1 who had been receiving steroids and immunosuppressives), and 3 had HIV wasting syndrome. These data suggest that the revision of the AIDS case definition will have a substantial impact on future AIDS surveillance trends in persons with hemophilia and perhaps in other risk groups.

Intestinal parasites in pet store puppies in Atlanta.

We examined 143 pups from 14 Atlanta area pet stores for intestinal parasites and reviewed deworming practices and information given to customers. Seventy-four (52 per cent) of the pups had at least one parasite including Giardia sp. (34 per cent), Toxocara canis (12 per cent), and Isospora sp. (9 per cent). Eighty-eight per cent received some form of anthelminthic treatment while at the store. Only six (43 per cent) of the stores routinely informed clients of the need to continue deworming procedures once the pup left the store.

Geographic variability of hemophilia-associated AIDS in the United States: effect of population characteristics. Hemophilia-Associated AIDS Study Group.

National AIDS surveillance suggests that approximately 3.5% of all hemophilic patients in the United States have developed AIDS as of February 1988; however, the cumulative incidence of AIDS among seropositive patients at individual hemophilia treatment centers (HTCs) has been reported to be as high as 12%. The purpose of this study was to examine the reported excess risk of AIDS at selected HTCs. Between July 13 and November 6, 1987, we reviewed medical charts from the 598 hemophilia A and hemophilia B patients receiving comprehensive care as of 1980 at six U.S. hemophilia treatment centers (three identified as low AIDS risk and three identified as high AIDS risk using national hemophilia-associated AIDS surveillance data). The risk of AIDS among all patients was 8% and among seropositive patients was 18%. At the individual HTCs, the risk ranged from 0% to 14% among all patients and 0% to 25% among seropositive patients. Overall incidence rates were higher than those derived from national surveillance data because national estimates include all hemophilic patients (regardless of severity) whereas this study included only patients receiving comprehensive care (who are more likely to be severely affected by their coagulation disorder and receive concentrated clotting factors). The higher incidence of AIDS in the high-risk centers was attributable to the older age of the patients in these HTCs, a factor previously associated with an increased risk of AIDS in seropositive patients. These findings do not support geographic variability in the incidence of AIDS and emphasize the importance of patient characteristics when comparing the incidence of hemophilia-associated AIDS between populations.

Hemophilia-associated AIDS in the United States, 1981 to September 1987.

Between January 1, 1981 and September 4, 1987, 407 cases of hemophilia-associated acquired immunodeficiency syndrome (AIDS) had been reported to the Centers for Disease Control. The number of cases diagnosed each year nearly doubled, except in 1986, when cases increased only 50 per cent. Demographic characteristics of the patients did not change over time. The majority (74 per cent) had severe hemophilia and 97 per cent received commercially produced concentrated clotting factors. The cumulative incidence of AIDS between 1981 and September 1987 for persons with severe hemophilia A was substantially greater than that for persons with severe hemophilia B (4.2 cases vs 1.9 cases per 100 persons).

Risk factors for hypoglycemia associated with pentamidine therapy for Pneumocystis pneumonia.

In 1984, three patients died of severe hypoglycemia after receiving pentamidine isethionate to treat Pneumocystis pneumonia. These deaths occurred on days 8, 12, and 19 of treatment, respectively. To assess risk factors associated with pentamidine treatment and hypoglycemia, we reviewed records of patients treated with pentamidine in New York City in 1984; ninety-seven percent of these patients had a diagnosis of acquired immunodeficiency syndrome. Hypoglycemia occurred in 23 (14%) of 164 patients. Hypoglycemia was more likely to occur in patients who received therapy of longer duration and an increasing dosage of pentamidine. Patients at greater risk for hypoglycemia also included those who had received pentamidine previously and those who experienced azotemia during treatment. This serious, potentially fatal, reaction should be considered in all patients who are treated with pentamidine, particularly those receiving prolonged or recurrent therapy.

Necrotizing enterocolitis mortality in the United States, 1979-85.

The Multiple Cause of Death Mortality data from the National Center for Health Statistics were analyzed to describe epidemiologic characteristics and trends in deaths related to necrotizing enterocolitis (NEC) among infants in the United States from 1979 to 1985. The average annual mortality rate (multiple cause mortality) for NEC was 13.1 deaths per 100,000 live births. NEC annual mortality rates decreased significantly during the study period for White and Black infants, male and female infants, and infants in the Northeast, North Central, and South regions. Black infants were approximately three times more likely to die from NEC than White infants, and the NEC infant mortality rate was highest in the South.