Evaluation of the WHO clinical case definition for AIDS in rural Zaire

The clinical case definition for AIDS proposed by WHO for use in Africa was evaluated against HIV antibody status in 72 patients in rural Zaire. Twenty-one (29%) of the patients were antibody-positive. For diagnosing anti-HIV seropositivity, the case definition had a sensitivity of 52%, a specificity of 78%, a positive predictive value of 50% and a negative predictive value of 80%. Calculation of the positive predictive value at different levels of prevalence of HIV infection suggests that the case definition operates at maximum reliability in selected high-risk groups. Modifications to the case definition should be evaluated to try and improve its sensitivity and positive predictive value.     

Evaluation of a clinical case definition of AIDS in African children

In July 1986, a provisional clinical case definition of AIDS in children, developed by the World Health Organization (WHO) for surveillance purposes in Africa, was tested on 159 patients hospitalized in the Department of Pediatrics at Mama Yemo Hospital, Kinshasa, Zaire. Twenty-one (13%) of these children were seropositive for HIV. In this population, the clinical case definition of pediatric AIDS was found to be fairly specific (87%) but lacked sensitivity (35%). The positive predictive value for HIV seropositivity was 25%. This study suggests that it is more difficult to define AIDS clinically in children than in adults and that the utility of the proposed WHO clinical case definition for pediatric AIDS for surveillance of children's AIDS in Africa is limited.     

Evaluation and simplification of the World Health Organization clinical case definition for paediatric AIDS

The World Health Organization (WHO) clinical case definition for paediatric AIDS was tested during a 1-month period on 221 consecutive hospitalized children in Kigali, Rwanda. Relevant clinical features not included in the WHO case definition were also evaluated. Thirty-four out of the 221 children (15.4%) were HIV seropositive. Although the specificity of the WHO case definition was high (92%), the sensitivity and the positive predictive value (PPV) were low (41 and 48%, respectively). The following individual signs had a PPV at least equal to the complete WHO case definition: chronic diarrhoea (47%), respiratory distress secondary to lower respiratory tract infection (50%), oral candidiasis (53%), parotitis (67%), generalized lymphadenopathy (88%), and herpes zoster infection (100%). When logistic regression analysis was done on the nine variables included in the WHO case definition, confirmed maternal infection was the best predictive variable for HIV seropositivity in children (P less than 10(-5). We further excluded the serological status of the mother from the analysis and performed a stepwise logistic regression analysis on the 18 clinical signs and symptoms for which information had been collected. Those signs and symptoms contributing the most to the regression were: respiratory distress, chronic diarrhoea and generalized lymphadenopathy. Based on these findings, we propose a simplified clinical case definition for paediatric AIDS in Africa with better sensitivity, specificity and PPV than the WHO case definition. Further work is needed using this approach to develop case definitions useful for epidemiological surveillance and for case management.     

The impact of the 1993 AIDS case definition on the completeness and timeliness of AIDS surveillance.

OBJECTIVE: To assess the impact of the 1993 change in the AIDS case definition on the completeness and timeframe of AIDS case reporting in San Francisco. DESIGN: Retrospective review of records: billing records, list of selected diagnostic codes, radiology logs, ophthalmology clinic records, and patient registries at a selection of hospitals, clinics, and physician offices. SETTING: Hospitals, public/community health clinics, and physician offices. MAIN OUTCOME MEASURES: The completeness of reporting and the median reporting delay was calculated for hospitals, clinics, and physician offices. RESULTS: Reporting was 97% complete. Reporting from physician offices was less complete (75%) than from other facilities. The median reporting delay was 1 month and was shorter for persons who met the 1993 AIDS case definition (1 month) than for persons who met the 1987 case definition (3 months). CONCLUSIONS: AIDS case reporting in San Francisco is highly complete but less so for persons diagnosed at physician offices. The 1993 AIDS case definition has resulted in more timely reporting. Health departments should consider efforts to improve reporting from private physician offices and should evaluate the use of laboratory-initiated CD4 reporting.     

Evaluation of the measles clinical case definition

An accurate system of identifying and classifying suspected measles cases is critical for the measles surveillance system in the United States. To examine the performance of the clinical case definition in predicting laboratory confirmation of suspected cases of measles, we reviewed 4 studies conducted between 1981 and 1994. A clinical case definition was examined that included a generalized maculopapular rash, fever (>or=38.3 degrees C, if measured), and either a cough, coryza, or conjunctivitis. Serological confirmation of measles was done either by hemagglutination inhibition assay, complement fixation assay, or enzyme immunoassays. The positive predictive value of the clinical case definition decreased from 74% to 1% as incidence decreased from 171 cases/100000 population to 1.3 cases/100000 population. Sensitivity was high, and for the larger studies with the most precise estimates, sensitivity was 76%-88%. The low positive predictive value of the clinical case definition in settings of low incidence demonstrates that serological confirmation is essential to ensure an accurate diagnosis of measles when measles is rare.     

Effect of the revised CDC case definition of AIDS on the number of AIDS cases in the Sydney AIDS Prospective Study

We sought to evaluate the potential impact of a proposed revision in the case definition of acquired immunodeficiency syndrome (AIDS) (from a clinical case definition to one also including subjects with HIV infection who have an absolute number of peripheral CD4 + cells of less than 200 times 10⁶/L) among 512 HIV-seropositive homosexual/bisexual who were reviewed between 1984 and 1991. According to the current case definition, 151 (30%) of 512 at-risk subjects developed AIDS between 1984 and August 1, 1991. Of the 361 at-risk subjects who were not classified as AIDS by the current definition, 47 (13%; 95% CI 9 – 17%) were classified as AIDS according to the revised definition. The median time to development of AIDS according to the revised definition was 288 weeks and that according to the current definition was 338 weeks. Data on clinical status were available for 34 of the new cases at the time of their diagnosis according to the proposed case definition: 16 (47%) of these were asymptomatic, 10 (29%) had persistent generalised lymphadenopathy and eight had minor infectious diseases. Of the 151 cases diagnosed according to the current definition, 78 (52%) had an antecedent CD4 + cell count that met the criteria for AIDS under the revised definition a median of 59 weeks before their diagnosis according to the current definition. These data indicate an appreciable increase in the number of cases of AIDS in this cohort when the revised case definition was applied. These findings have important implications for the surveillance, and for the clinical monitoring and treatment, of patients with HIV disease in Australia.     

Cardiomyopathy: a necessary revision of the WHO classification

The classification of myocardial disease proposed by the WHO/ISFC task force in 1980 distinguishes specific heart muscle diseases from myocardial diseases of unknown origin, termed cardiomyopathies, and differentiated into the dilated, hypertrophic and restrictive forms. This last group includes endomyocardiofibrosis and fibroblastic parietal endocarditis. In more recent years, two new forms of heart muscle disease have been recognized: so-called "primary" restrictive cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Primary restrictive cardiomyopathy is characterized anatomically by normally sized, non-hypertrophic ventricles with dilated atria, and functionally by impaired diastolic compliance due to myocardial stiffness. The clinical picture is that of chronic congestive heart failure; histology shows interstitial fibrosis and myocardial disarray, but not hypereosinophilia. In arrhythmogenic right ventricular cardiomyopathy, the myocardium of the right ventricular free wall is substituted by fibrous and/or adipose tissue, which results in regional dynamic alterations and ominous ventricular arrhythmias. The left ventricle is usually spared. Both forms should be classified as heart muscle diseases of unknown origin, and kept clearly distinct from the other cardiomyopathies listed in the WHO classification.     

A standardized definition of ischemic cardiomyopathy for use in clinical research.

OBJECTIVES: We sought to evaluate the association between the extent of coronary artery disease (CAD) and survival in patients with symptomatic heart failure (HF) and to create the most prognostically powerful clinical definition of ischemic cardiomyopathy. BACKGROUND: An ischemic etiology of HF is known to be a predictor of adverse outcome; however, there is no uniform definition for ischemic cardiomyopathy. METHODS: We assessed the clinical history and coronary anatomy of patients with symptomatic HF and ejection fraction < or = 40% undergoing diagnostic coronary angiography between 1986 and 1999 (n = 1,921). Five classification schemes were tested to identify the most prognostically powerful method for defining the extent of CAD and to develop the best definition of ischemic cardiomyopathy for prognostic purposes. RESULTS: A more extensive CAD was independently associated with shorter survival. When the various classification schemes were compared, a modified number-of-diseased-vessels classification, in which patients with single-vessel disease and no prior history of revascularization or myocardial infarction (MI) were classified as nonischemic, provided the most prognostic power. A definition of ischemic cardiomyopathy that incorporated this definition had more prognostic power than the traditional definition. CONCLUSIONS: Angiographically diagnosed ischemic HF is associated with shorter survival than nonischemic HF. A more extensive CAD is independently associated with shorter survival, and patients with single-vessel disease and no history of MI or revascularization should be classified as nonischemic for prognostic purposes. Standardization of the definition of ischemic cardiomyopathy will be useful in the conduct and interpretation of clinical research in HF.     

Lympho-cutaneous Kaposi's sarcoma in an African pediatric AIDS case

A case of disseminated Kaposi's sarcoma with lymphoid and mucocutaneous involvement in an African infant with acquired immune deficiency syndrome is reported. The child died within 2 months after recognition.     

Human-resources strategies for managing HIV/AIDS: the case of the South African forestry industry

Previous work has focused on HIV prevalence among forestry workers and the impact of HIV/AIDS on the sustainability of forest resources. Following a review of work examining the impacts of HIV/AIDS on the South African economy, this article presents original qualitative research examining the responses of company management to the HIV epidemic across a range of enterprises in the South African forestry industry, including large companies, contractors and cooperatives. At the level of the enterprise, management occupies a critical nexus, at which the intersecting requirements of complex government legislation, the wellbeing of workers and the demands of the business must be met. The research demonstrates that large forestry companies tend to provide only a small fraction of their workforces with HIV/AIDS education, prevention or treatment services, as they have essentially outsourced the requirement through the use of labour-supply contractors who, by and large, provide workers with scant HIV/AIDS-related programmes or benefits. Moreover, the extent to which the different types of forestry enterprises incorporate the management of HIV/AIDS in the workforce with the management of the business is highly variable, and in most instances falls short of legislative requirements that have been in place for over a decade. The implications of this for the forestry industry in South Africa are acute.     

WHO and ATPIII proposals for the definition of the metabolic syndrome in patients with Type 2 diabetes.

AIMS: Different criteria have been proposed by the World Health Organization (WHO) and by the Third Report of the National Cholesterol Education Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATPIII) for the diagnosis of the metabolic syndrome. Its identification is of particular importance for coronary risk assessment. METHODS: The prevalence of the metabolic syndrome was determined according to the two different proposals in 1569 consecutive subjects with Type 2 diabetes. RESULTS: By the WHO proposal, 81% of cases (95% confidence interval, 79-83) were labelled as metabolic syndrome. Microalbuminuria had the highest specificity (99%) and visceral obesity the highest sensitivity (93%). Seventy-eight per cent of patients (95% CI, 76-80) fulfilled the ATPIII criteria for metabolic syndrome, low HDL-cholesterol having the highest specificity (95%), elevated blood pressure having the highest sensitivity. According to both proposals, 1113 patients were positive; 183 were concordantly negative, indicative of a fairly good agreement (k statistics, 0.464). Subjects only positive for the WHO proposal were more frequently males, had a lower BMI and a higher arterial pressure. Only subjects identified by the ATPIII proposal had a significantly higher prevalence of previously detected coronary heart disease. CONCLUSIONS: Minimum criteria for the metabolic syndrome are met in most patients with Type 2 diabetes. Correct identification of the syndrome is important for an integrated approach to reduce the high costs and the associated disabilities. The ATPIII proposal more clearly identifies the burden of coronary heart disease associated with the metabolic syndrome.     

Survival in a cohort of human immunodeficiency virus-infected tuberculosis patients in New York City. Implications for the expansion of the AIDS case definition.

BACKGROUND. The occurrence of pulmonary tuberculosis in human immunodeficiency virus (HIV)-infected persons is believed to represent a less severe stage of HIV-related disease with a more favorable prognosis than other acquired immunodeficiency syndrome (AIDS)-defining conditions; therefore, it has been excluded from the AIDS definition established by the Centers for Disease Control (Atlanta, Ga) criteria. METHODS. To determine the prognosis of patients with HIV-related tuberculosis, we assessed the clinical, immunologic, and HIV infection status of a cohort of male subjects aged 20 to 44 years who were hospitalized with tuberculosis but without AIDS in New York City hospitals from 1985 through 1986, and we determined their mortality through May 1991. RESULTS. The 58 patients who agreed to participate were largely (90%) nonwhite and had a high prevalence of pulmonary tuberculosis (90%) and HIV infection (53%). Patients who were HIV seropositive had significantly lower CD4 cell counts (median, 0.136 x 10(9)/L; range, 0.013 x 10(9) to 2.314 x 10(9)/L vs median, 0.765 x 10(9)/L; range, 0.284 x 10(9) to 2.333 x 10(9)/L), and, during the follow-up period, an 83% mortality rate that was 7.5 times higher than the 11% rate in seronegative subjects. Survival analyses revealed that for all HIV-seropositive subjects the probability of death at 30 months was 72% and the median survival was 21 months (95% confidence interval, 15.5 to 26.5 months), while for HIV-seropositive subjects with CD4 cell counts of 0.2 x 10(9)/L or less, the probability of death at 30 months was 92% and the median survival was 15.75 months (95% confidence interval, 14.0 to 17.6 months). CONCLUSION. The prognosis for patients with HIV-related pulmonary tuberculosis is poor, and those with CD4 cell counts of 0.2 x 10(9)/L or less have survival patterns similar to that of patients with AIDS. We believe that these data support the expansion of the AIDS case definition to include persons with both pulmonary tuberculosis and severe HIV-related immunosuppression.