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S J Heymann

Publications and source records attributed to S J Heymann.

24 records · Page 2Linked to original sources
PubMed1992

The problem of transfusion-associated acquired immunodeficiency syndrome in Africa: a quantitative approach.

BACKGROUND: Transfusion-associated AIDS accounts for 10% of all cases of AIDS in Africa. The risk of HIV-1 contamination in transfusions continues to exist, even in countries where blood products are screened, because of limitations in test sensitivity, human error, and the window period. Furthermore, 30 African countries do not screen all of their blood products because of resource limitations. METHODS: This study used decision analysis to compare the survival outcomes of severely anemic patients who are transfused with those of patients who are not transfused. Sensitivity analyses were performed. RESULTS: When 5% of the blood supply is HIV-1 contaminated, every patient with a 6.6% or greater risk of dying from anemia should be transfused. Detailed results are provided for a wide range of HIV-1 contamination rates. CONCLUSIONS: This study provides a method for developing and evaluating locality-specific transfusion guidelines. This method can be applied to other regions, including the United States, and to other diseases transmitted by blood products.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Modeling the impact of breast-feeding by HIV-infected women on child survival.

This study models the survival outcomes of children born to HIV-infected (human immunodeficiency virus) women who are breast-fed, bottle-fed, and wet-nursed. It is estimated that, given the relative risk of alternatives to maternal milk in developing countries, the probability of HIV transmission via breast milk would need to be at least .12 in a community with an under five child mortality rate from non-HIV causes of 100/1000 live births and at least .27 in a community with a rate of 200/1000 before alternative feeding practices should be recommended even to the known HIV-infected mother who has an available feeding alternative with a relative risk of 2:1. While such a low relative risk may be achievable with wet nursing, most studies report a relative risk of at least 3:1 for bottle feeding. A sensitivity analysis is conducted around the relative risk of child mortality from non-HIV causes associated with different feeding practices. While the critical transmission rate does not vary significantly with a rate of false positives as high as 20 percent on the HIV screening test, the critical transmission rate is very sensitive to the availability of HIV screening. In communities where the HIV prevalence rate among mothers reaches 40 percent, breast-feeding should still be recommended in the absence of HIV screening unless HIV transmission via breast milk surpasses 30 percent.

Breast Feeding↗
PubMedDate not supplied

Modelling the efficacy of prophylactic and curative therapies for preventing the spread of tuberculosis in Africa.

Concerns have been raised about whether the interaction between tuberculosis and human immunodeficiency virus (HIV) may lead worldwide to a recrudescent tuberculosis pandemic. These concerns are particularly grave in Africa which has a high prevalence of both tuberculosis and HIV. This study used a computer simulation model to examine the effect of tuberculosis-HIV interactions on tuberculosis prevalence and mortality in Africa. The model then assessed the impact of expanding treatment and chemoprophylaxis programmes on tuberculosis prevalence and mortality over the next decade. In communities where 20% of the population is infected with HIV and 25% receive treatment for tuberculosis, deaths from tuberculosis would be 100% higher than in communities where none of the population is HIV-infected. In a population the size of Uganda's, during one decade there would be approximately an additional 530,000 deaths from tuberculosis. When 50% of patients with active tuberculosis receive treatment, one death will be averted for every 2.5 people who receive treatment. The prevalence of active tuberculosis could be cut by over 90% in a decade by providing effective chemoprophylaxis to 30% of individuals with inactive TB. In conclusion, TB is only one example of a preventable and treatable infectious disease which can be spread through casual contact and which, because of its higher prevalence among the HIV positive population, may lead to a preventable increase in incidence of infection among the general population.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Effectiveness and cost of rapid and conventional laboratory methods for Mycobacterium tuberculosis screening.

OBJECTIVE: Because delay in the diagnosis of tuberculosis (TB) contributes to the spread of disease and the associated mortality risk, the authors examined the effectiveness and cost of recent advances in methods of diagnosing TB and testing for drug susceptibility, comparing these rapid methods to traditional approaches. METHODS: Decision analysis was used to compare newer rapid and older nonrapid methods for diagnosing TB and testing for drug susceptibility. The average time to diagnosis, average time to treatment, average mortality, and cost of caring for patients evaluated for TB were compared. RESULTS: Using a combination of solid medium and broth cultures, nucleic acid probes for identification, and radiometric broth drug susceptibility testing would lead to diagnosis on average 15 days faster and to appropriate therapy on average five days sooner than methods currently employed by many U.S. laboratories. The average mortality would drop by five patients per 1000 patients evaluated (31%) and the average cost per patient would drop by $272 (18%). CONCLUSIONS: In this era of cost containment, it is important to incorporate test sensitivity and specificity when evaluating technologies. Tests with higher unit costs may lead to lower medical expenditures when diagnostic accuracy and speed are improved. U.S. laboratories should employ available rapid techniques for the diagnosis of TB.

Bacteriological Techniques↗