Definition Of AIDS Research Articles

Surveillance of Acquired Immunodeficiency Syndrome in Africa

In order to improve public health efforts to combat the HIV pandemic a system for surveillance of HIV and AIDS is needed. Definitions used for case reporting are at the heart of such a system. In many parts of Africa however facilities for diagnosing HIV infection and its subsequent complications are unavailable and the definition developed by the US Centers for Diseases Control and Prevention (CDC) for use in developed countries is often impractical in Africa. The World Health Organization (WHO) in early 1985 therefore proposed using a provisional case definition of AIDS based principally upon clinical criteria. Developing a clinical definition of AIDS in Africa however is also complicated. The nonspecific nature of many of the signs and symptoms of HIV infection as well as the clinical redundancy between HIV and other epidemic health problems make definitive identification of any single disease problematic. Evaluation of the surveillance definition of AIDS in Africa is complicated by the lack of an accepted standard for comparison. Most studies in the field have used HIV serology as the standard while others have employed the CDC definition for AIDS giving the evaluations a certain relativity. This paper reviews available information on the WHO definition and other clinical definitions for AIDS in Africa in order to analyze their various field evaluations and explore the use of such definitions in the African context. Sections discuss surveillance clinical case definitions for African AIDS in adult and pediatric populations clinical case definitions of African AIDS in adult and pediatric populations sensitivity and specificity the WHO clinical case definition for HIV epidemiologic survey clinical definitions for AIDS in clinical practice and working toward the improvement of the clinical definition of AIDS.

Limitations of the WHO/CDC clinical case definition for AIDS in Africa.

The authors screened 268 patients over the period July-September 1990 selected by systematic sample from those attending the sexually transmitted diseases section of the adult filter clinic at the University Teaching Hospital in Lusaka Zambia. Clinical findings were recorded to establish whether each patient fulfilled the World Health Organization (WHO) clinical case definition for AIDS. For pragmatic reasons the presence of oral candida any episode of herpes simplex and any episode of herpes zoster were considered positive criteria. Participants were also examined for the presence of palpable epitrochlear lymph nodes enlarged to one centimeter or more. Blood was drawn for analysis for HIV-1 antibody using HIVCHEK and for syphilis using Syfacard-R. 158 participants were found to be HIV-1 seropositive. It was also determined that current WHO criteria for the clinical case definition of AIDS offers only low positive predictive value and sensitivity. The authors therefore urge that caution be taken in interpreting that case definition and that serological testing for HIV be used in conjunction with the clinical case definition whenever possible. HIVCHEK can be routinely used in areas where there is no serological evidence of HIV-2. Furthermore epitrochlear adenopathy is a simple clinical finding which has in this study a positive predictive value for HIV infection of 77%; a similar study in Zambia showed a positive predictive value of 89%. Further studies are needed to validate this finding in other settings but the presence of the nodes may provide an additional clinical criterion for predicting HIV seropositivity in the absence of other known causes of epitrochlear lymphadenopathy.

The epidemiology of AIDS-related malignancies

Immunosuppression resulting from HIV infection does not explain the unique distribution of Kaposi's sarcoma across risk groups. A majority of cases occur among homosexual men, particularly those with oral-anal contact, those with sexual contacts in high-risk cities, and those frequently use nitrite inhalants, suggesting a currently unidentified etiologic cofactor. Risk of non-Hodgkin's lymphoma among HIV-infected persons continues to increase over time. Because all HIV-infected groups are at high risk of non-Hodgkin's lymphoma, environmental cofactors may be less important in the disease's etiology. Because data on risk factors for AIDS-related non-Hodgkin's lymphoma are limited, further studies are needed. Cohort studies suggested that the risk of Hodgkin's disease is greater among HIV-infected persons; however, the number of cases reported has been small. Hodgkin's disease occurring among HIV-infected persons is more aggressive than and differs in presentation from that among noninfected persons. The addition of invasive cervical cancer to the US Centers for Disease Control definition of AIDS is based on data showing that HIV-infected women have a high prevalence of cervical disease. Although no conclusions can yet be drawn regarding the temporal relationship of cervical disease and HIV infection, there is evidence of a direct relationship between the degree of HIV-induced immunosuppression and the extent of cervical disease. Other cancers are being diagnosed among AIDS patients, and monitoring of the risk of solid tumors among various cohorts of high-risk and HIV-infected persons continues.

New AIDS Definition Increases AIDS Cases by 205%

New AIDS Definition Increases AIDS Cases by 205%

Effects of new AIDS definition on figures

Effects of new AIDS definition on figures

CDT Acts on Mouthrinses; Plans to Host Workshop on Home-Use Whiteners / International Research Project Focuses on Restorative Materials / Fear Causes 14 Million Patients to Skirt Dental Treatment, Survey Shows / CDR Revises AIDS Definition / PHS AIDS Document Available / OSHA ‘Helpline’ Opens / Health Media Watch

CDT Acts on Mouthrinses; Plans to Host Workshop on Home-Use Whiteners / International Research Project Focuses on Restorative Materials / Fear Causes 14 Million Patients to Skirt Dental Treatment, Survey Shows / CDR Revises AIDS Definition / PHS AIDS Document Available / OSHA ‘Helpline’ Opens / Health Media Watch

Clinical and epidemiological implications of the Centers for Disease Control/World Health Organization reclassification of AIDS cases

To establish whether various accepted and proposed AIDS definitions have clinical and biological validity: because the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) reclassifications of AIDS are important not only for describing the epidemiology of HIV disease but also to individual patients. Regional Infectious Diseases Unit, City Hospital, Edinburgh, Scotland, UK. We analysed the disease progression of 532 HIV-seropositive individuals seen at the City Hospital, Edinburgh, up to the end of July 1991. Annual numbers of potentially reportable cases from the Edinburgh City Hospital Cohort according to three proposed AIDS case definitions based on: (1) first lymphocyte count < or = 1000 x 10(6)/l; (2) first CD4 cell count < or = 200 x 10(6)/l; or (3) first of two consecutive CD4 cell counts < or = 200 x 10(6)/l. Lifetables to death (irrespective of cause) from month of satisfying the above case definitions, and proportion of patients who satisfied each definition in their calendar year of enrollment in the cohort are reported. There is a threefold increase in patients in the Edinburgh City Hospital Cohort defined as having AIDS under the 1987 and the proposed 1992 CDC definitions--a substantial change for patients and epidemiologists alike. That they are describing different immunodeficiency states is clear from lifetable analysis, which reveals median survivals of 20 and 50 months under the 1987 and the proposed 1992 AIDS definitions, respectively. For epidemiological purposes, redefinitions based on the WHO proposed classification of HIV disease using either a lymphocyte count < or = 1000 x 10(6)/l or a CD4 cell count < or = 200 x 10(6)/l are broadly interchangeable. They are not equally effective for monitoring individual progression (CD4 cell count is superior). Both, for different reasons, lack biological plausibility. We therefore suggest that the stricter, biologically more plausible, case definition used in Scotland of two consecutive CD4 cell counts of < or = 200 x 10(6)/l [CD4(200) (x 2)] should be adopted--not as a new definition of AIDS, but as an additional important state of severe HIV-related immunodeficiency (SHRID). Median survival under the CD4(200) (x 2) case definition was 40 months in the Edinburgh cohort. We have illustrated differences in CD4(200) case ascertainment between injecting drug users and other HIV-infected patients in the Edinburgh City Hospital Cohort. We recommend that surveillance centres should ascertain date of first immunological monitoring as well as date of SHRID diagnosis in order to identify differential case ascertainment.

The foramen magnum: the underutilized acoustic window to the posterior fossa.

Visualization of the posterior fossa during neonatal cranial sonography through the anterior fontanelle can at times be limited. To improve visualization of the posterior fossa, the foramen magnum was used as an acoustic window. Scans through the foramen magnum were obtained in addition to routine scans via the anterior fontanelle in 21 preterm infants. A subjective and retrospective evaluation was performed comparing clarity and definition of posterior fossa structures using the anterior fontanelle and foramen magnum. Images of the fourth ventricle, pons, vermis, cerebellar hemispheres, and cisterna magna were considered superior in clarity and definition when obtained via the foramen magnum. The tentorium was visualized equally well with both windows. Foramen magnum scanning demonstrated improved clarity of two Dandy-Walker variants in comparison to anterior fontanelle scanning. The use of the foramen magnum in addition to other acoustic windows can improve perceived clarity and definition of posterior fossa structures and aid in the detection of abnormalities and anomalies occurring in this location.

Nutritional assessment of drug addicts. Relation with HIV infection in early stages

Objective: To assess the nutritional status of drug addicts without acute organic pathology, in order to determine the prevalence of malnutrition and to discern if early HIV infection is associated with a poor nutritional status in this group of patients. Design: Prospective study. Setting: Detoxication unit of a university hospital. Patients: 140 drug addicts without acute organic pathology. 31 patients were HIV+. No one fulfilled the definition of AIDS. Results: We found that drug addicts were undernourished: 92.4% weighed under the mean populational weight and 55.7% had a weight loss above 5%. The distribution of mid upper arm circumference (MUAC), triceps skinfold (TSF) and mid arm muscle area (MAMA) was lower than a reference normal population. Food intakes were poor; 66.4% of our patients complained of anorexia on admission. The mean caloric intake was 978 ± 89 kcal/day in females and 1265 ± 64 kcal/day in males. The mean protein intakes were 39.3 ± 3.3 g/day in females (0.76 ± 0.07 g/kg/day) and 49.7 ± 2.7 g/day in males (0.77 ± 0.04 g/kg/day). When we compared nutritional parameters between HIV+ and HIV- patients we found no differences. Conclusions: Nutritional impairment in drugs abusers with early stages of HIV infection should be attributed to drug abuse rather than to HIV infection.

HIV, AIDS, and Africa

There is a low incidence of HIV infection in Cameroon, Djibouti, Ethiopia, Gabon, Gambia, Ghana, Guinea, Lesotho, Madagascar, Nigeria, Somalia, and Swaziland, but the risk of the spread of HIV infection and AIDS is high because these sub-Saharan African countries have a high incidence of sexually transmitted diseases (STDs). A World Bank report suggests that these countries establish prevention and treatment programs targeting core transmitters (e.g., prostitutes and their clients) to prevent the spread of STDs in order to reduce HIV transmission. These programs should not limit themselves to just STDs that foster HIV transmission, however, because all STDs affect health and fertility. The report also encourages that HIV/STD prevention and treatment efforts be incorporated into existing health programs, such as maternal health and family planning programs. It cautions against having HIV/AIDS efforts drain resources from curable diseases and much needed activities to develop health systems Health providers in Africa are treating more and more patients with HIV infections and AIDS. Therefore, they should have reliable, relevant, and current information on HIV/AIDS diagnosis and management, but most information now deals with patients in Europe and North America. WHO has prepared a manual for physicians which includes a comprehensive description of the clinical manifestations of HIV in Africa and current guidelines on its management. In addition to the WHO clinical definition of AIDS, the manual provides clinicians features which may help them diagnose AIDS, e.g., short episodes of diarrhea, fever of unknown origin, and nonreactivity to intradermal tuberculin skin testing. The manual notes that most African countries face a lack of simple and inexpensive laboratory tests to diagnose HIV, yet widespread testing would burden their health systems.

HIV-1 and parasitic infections in rural Tanzania.

A sample of 300 sexually-active adults was selected at random from patients, from the rural area of Malenga Makali, Tanzania, who were attending a dispensary because they had diarrhoea of at least 2 weeks' duration. The potential associations between the patient's health (in terms of the World Health Organization's clinical definition of AIDS), HIV-1 seroprevalence and malaria and other parasitic infections were then investigated. Although, HIV-1 seroprevalence was 20.6% overall, the level of seroprevalence was directly correlated with the distance between the patients' home villages and the nearest main road. Strict application of the clinical definition of AIDS gave 98.7% specificity, 46% sensitivity and a predictive value of 90.6% when validated by HIV-1 seropositivity. Although malaria infection was more common in HIV-1 seropositives than in the seronegatives, the intensity of the Plasmodium falciparum infections, intestinal amoebiasis and giardiasis did not appear to be correlated with HIV-1 infection. In contrast, intestinal infections with Cryptosporidium parvum and Isospora belli were virtually restricted to HIV-1 seropositive individuals who had had diarrhoea for a relatively long time.

A Matter of FACS: Constituting Novel Entities in Immunology

This article contributes to the development of an anthropology of biomedicine that takes as its subject matter the content of biomedical knowledge and practices. It offers an ethnographic account of the establishment of the international classification of white blood cells, known as the “CD nomenclature,” and goes beyond the assertion that biomedical knowledge is “socially constructed,” providing a fine‐textured analysis of how, in this specific case, knowledge was constituted. The CD nomenclature found its way into newspapers and daily medical practice mainly through the involvement of the CD4 subclass of lymphocytes (white blood cells) in AIDS definition and diagnosis. The establishment of the CD nomenclature is thus part of the recent movement of immunology to the center stage of the biomedical sciences. This study analyzes the articulation of the elements (institutions, tools, concepts) that made the classification possible. By focusing on the material practices of immunologists, the analysis shows that the present‐day classification of lymphocytes has as its precondition the constitution of a network for the establishment of identities between immunological reagents produced by different laboratories. Furthermore, it is argued that the standards by which identities are established are inseparable from the entities (lymphocyte subsets) that are classified. Finally, it is claimed that an ethnography of the practices by which such a network comes into being provides an adequate analysis of the constitution of knowledge, specifically, of scientific information about the entities known as lymphocyte subsets.

A SIMPLIFIED SURVEILLANCE CASE DEFINITION OF AIDS DERIVED FROM EMPIRICAL CLINICAL DATA

A clinical AIDS case definition is needed for surveillance in countries where the CDC case definition is not practical. To derive such a definition, we compared 110 HIV-seropositive and 135 randomly selected HIV-seronegative adult medical-ward inpatients in Brazil. Multivariate analysis of clinical signs and symptoms and simple diagnoses resulted in a discriminant function with sensitivity of 89% and specificity of 96% in predicting for AIDS. These data were the empirical basis for a clinical definition of AIDS in adults drafted in a Caracas, Venezuela, workshop sponsored by the Pan American Health Organization. The revised "Caracas" definition presented here requires a positive HIV serology, the absence of cancer or other cause of immunosuppression, plus > or = 10 cumulative points, as follows: Kaposi's sarcoma (10 points); extrapulmonary/noncavitary pulmonary tuberculosis (10); oral candidiasis or hairy leukoplakia (5); cavitary pulmonary/unspecified tuberculosis (5); herpes zoster < 60 years of age (5); CNS dysfunction (5); diarrhea > or = 1 month (2); fever > or = 1 month (2); cachexia or > 10% weight loss (2); asthenia > or = 1 month (2); persistent dermatitis (2); anemia, lymphopenia, or thrombocytopenia (2); persistent cough or any pneumonia except TB (2); and lymphadenopathy > or = 1 cm at > or = 2 noninguinal sites for > or = 1 month (2). This definition has a sensitivity of 95% and a specificity of 100% (91% without HIV serology) when applied to the Brazilian patients in this study. The Caracas definition has been adopted by Brazil, Honduras, and Surinam, and is in validation elsewhere. The use of a reasonably sensitive and specific case definition commensurate with available diagnostic resources should facilitate AIDS surveillance in developing countries.

Call for definition of AIDS to cover women's conditions.

The definition of AIDS should be changed to include gynaecological conditions, delegates heard.

Round the World: USA: New AIDS definition

Round the World: USA: New AIDS definition

Implications of the revised surveillance definition: AIDS among New York City drug users.

The Centers for Disease Control (CDC) has proposed revising the AIDS surveillance definition to include any HIV-seropositive person with a CD4 cell count of less than 200 cells per microliter. Based on a study of persons receiving treatment for HIV infection, this new definition would lead to an estimated 50% increase in the number of persons recognized as living with AIDS. Among 440 HIV-seropositive research subjects recruited from drug treatment programs and through street outreach in New York City, 59 met this definition, yet only 25% of those had been reported to the New York City AIDS registry. The new definition, if combined with HIV and T-cell testing at drug treatment and street outreach programs, could thus yield very large increases in the number of injecting drug users meeting the new surveillance definition of AIDS.

Ad Mortem: An AIDS Performance Project

The AIDS crisis has challenged our understanding of death and our ways of living at every level of experience. In the face of confusion over the representation of AIDS in social service, educational and popular discourses, and a government that was/ is slow to act, the energy of confronting the disease has come from the people most directly affected. As AIDS hits hard among the art communities, new work is being created that gives to a shared sense of loss and anger. But it is also clear that not everybody in our society shares this sense, and when a widespread lack of compassion coincides with the conservative censorship-backlash against free expression, the stakes are raised and each giving voice to the experience of living with AIDS becomes a means of survival—and a political act. What is at stake, in my mind, is the idea of community itself. If the AIDS epidemic has produced a radical challenge to cultural perceptions of sexuality, dying, mourning, and healing, a performance that confronts taboos and political conflicts over the definition of AIDS will have to speak of the creators' knowledge of AIDS and their relationships to the affected communities. Dedicating a work to the struggle against AIDS involves testing one's own personal and political choices and resistances and, perhaps more importantly, examining one's own percep- tion of community.

High HIV seroprevalence and increased HIV-associated mortality among hospitalized patients with deep bacterial infections in Dar es Salaam, Tanzania

To correlate deep bacterial infections with HIV infection and evaluate the influence of HIV on clinical picture and outcome in patients with meningitis, pneumonia or pyomyositis. Case-control comparison of HIV seroprevalence between patients and an age- and sex-matched control group in a prospective cross-sectional study of hospitalized patients. One hundred and sixty-five patients admitted to hospital with either purulent meningitis, pneumonia or pyomyositis and 165 age- and sex-matched controls from orthopaedic/trauma wards. University Hospital, Dar es Salaam, Tanzania. Differences in HIV seroprevalence and mortality. Of 78 patients with purulent meningitis, 19 (24%) were HIV-seropositive, compared with 13 (17%) in the control group (P = 0.345). Of 36 patients with meningitis seen before a meningococcal epidemic affected Dar es Salaam, there was a statistically significant association with HIV infection (P = 0.013). Ten out of 19 (53%) HIV-seropositives died, compared with nine out of 59 (15%) seronegatives (P = 0.028). Of patients with pneumococcal meningitis, five out of six (83%) seropositives died, compared with two out of 12 (17%) seronegatives (P = 0.013). Fifteen out of 45 (33%) patients with pneumonia were HIV-seropositive, compared with four (9%) in the control group (P = 0.001). There was no difference in mortality between seropositive and seronegative patients with pneumonia. HIV seroprevalence was 62% among 42 patients with pyomyositis and 12% among 42 controls (P less than 0.0001). Eighteen out of 25 (72%) seropositive patients with pyomyositis fulfilled the World Health Organization (WHO) clinical case definition for AIDS. Response to recommended antibiotic treatment was satisfactory among patients with pneumonia and pyomyositis. These results show a strong association between pyomyositis, pneumonia and HIV infection. They also indicate an increased mortality associated with HIV infection in patients with pyogenic meningitis, especially pneumococcal meningitis. Pyomyositis should be considered an indicator of stage III HIV disease in the proposed WHO clinical staging system.

A case for the revision of the WHO clinical definition for African AIDS

In 1985 the WHO proposed an essentially clinical case definition of adult and pediatric AIDS for national and international surveillance of AIDS cases in Africa the Bangui definition. WHO initially intended this definition to be provisional and envisaged adopting the clinical definition for AIDS only after official evaluation in the field. In adults the Bangui definition is derived from the most widely encountered picture of African AIDS characterized by a particular cachectic syndrome (slim disease). The Bangui definition is easily applicable in the field without laboratory facilities and is equally applicable to HIV-1 and HIV-1 infections. Its positive predictive value for possible HIV infection is particularly high in endemic areas. Its 90% specificity is acceptable except in certain patients suffering from cachectic syndromes such as tuberculosis. However its 60% sensitivity is relatively low suggesting that there is substantial underrecognition of HIV-related diseases notably the acute or subacute affections that tend to differ from slim disease. After 5 years application in sub-Saharan Africa the Bangui definition for AIDS in adults has been adopted by all health care workers dealing with AIDS. In contrast to the adult definition the provisional WHO clinical case definition for pediatric AIDS has 2 major drawbacks that considerably limit its use for the surveillance of AIDS cases in African children. With its combination of 9 criteria including 1 biological criterion (serological status of the mother) the Bangui definition is difficult to apply in field conditions. Although its 90% specificity is relatively high its 35% sensitivity and positive predictive value are very low. These factors explain the failure of the Bangui definition to detect the majority of full blown pediatric AIDS cases in endemic areas particularly when a child suffers predominately from acute or chronic respiratory diseases or from neurological disorders. We propose that the Bangui criteria for AIDS should not be revised. First the HIV epidemic in Africa continues to spread and AIDS in certain urban centers is already a major cause of infant death emphasizing the urgent need for a valid definition of the epidemiological notification of AIDS cases. Second whenever the laboratory diagnoses of HIV infection is not systematically applied in Africa a clinical definition for AIDS is necessary. Indeed since 1985 numerous data on African AIDS have been produced leading to an improved understanding of the characteristics of African AIDS. Epidemiologists and clinicians should agree on the revised criteria and how to combine them. For example the addition of neurological signs as a minor criterion could increase the sensitivity of both the adult and pediatric clinical definitions for AIDS and suppression of the criterion chronic cough could increase their specificity. A simple revision of the Bangui definition could increase the notification of AIDS in African countries particularly in pediatric cases thus having an important impact on public health. (full text) (6 references cited in original document)

Is the worst of the epidemic over? Back calculation of HIV seroprevalence in The Netherlands

This article calculates back the HIV seroprevalence in the Netherlands from AIDS cases notified 1982–1990 and rates of progression from HIV to AIDS adopted from American studies. It discusses a number of problems, such as changing AIDS definitions and the possible impact of AZT treatment. We estimate that the Netherlands had approximately 6762 HIV seropositives by the end of 1988, which is considerably lower than earlier expectations. When a hypothetical decrease of 10% in the manifestation of AIDS cases due to AZT treatment was incorporated, the estimate for the end of 1988 becomes 7549. After deduction of the AIDS patients who had died by the beginning of 1989 from this estimate, the HIV seroprevalence by the end of 1988 is approximately 7000. The distribution of seroincidence over time suggests that the HIV epidemic in our country has passed its summit and that the HIV incidence is falling quickly. The question arises as to how far this fortunate development may be considered a success of the Dutch AIDS policy, a policy characterised by more openness than in many other countries. The material studied here, however, allows no definite answer to this intrigueing question.