Epidemiology and ecology of the sylvatic cycle of African Swine Fever Virus in Kenya.

African Swine Fever (ASF) is caused by a DNA virus (AFSV) maintained and transmitted by the Argasid ticks. The re-emergence of the disease in Africa coupled with its rapid spread globally is a threat to the pig industry, food security and livelihoods. The ecology and epidemiology of the ASFV sylvatic cycle, especially in the face of changing land use and land cover, further compounds the menace and impacts of this disease in Kenya.

An open-label assessment of TMC 125--a new, next-generation NNRTI, for 7 days in HIV-1 infected individuals with NNRTI resistance.

Unlabelled: The development of resistance to any of the currently licensed non-nucleoside reverse transcriptase inhibitors (NNRTI) invariably leads to cross-resistance to the drugs in that class. New NNRTI, that have the promise of being active even when such 'signature' mutations are present, are in development. Such novel therapies could be effective after current NNRTI failure as there would probably be no cross-resistance.

Recovering true risks when multilevel exposure and covariables are both misclassified.

The authors extend previous results on nondifferential exposure misclassification to the situation in which multilevel exposure and covariables are both misclassified. They show that if misclassification is nondifferential and the predictive value matrices are independent of other predictor variables it is possible to recover the true relative risks as a function of the biased estimates and the misclassification matrices alone. If the covariable is a confounder, the true relative risks may be recovered from the apparent relative risks derived from misclassified data and the misclassification matrix for the exposure variable with respect to its surrogate.

Linear extrapolation models of lung cancer risk associated with exposure to environmental tobacco smoke.

This paper presents a model to estimate the number of lung cancer deaths due to ETS exposure among the 1992 U.S. never-smoking population, based on downward linear extrapolation from the estimated risks of active smokers.

Use of multiple surveys to estimate mortality among never, current, and former smokers: changes over a 20-year interval.

Objectives: This study sought to demonstrate how data from publicly available large-scale cross-sectional health surveys can be combined to analyze changes in mortality risks among never, current, and former smokers.

Methods: Data from the 1966/68 and 1986 National Mortality Followback Surveys and the 1970 and 1987 National Health Interview Surveys were used to estimate the distribution of never, current, and former smokers among the US population at risk and decedents. Standardized mortality ratios and quotients of standardized mortality ratios were used to estimate mortality risks.

An alternative explanation for the apparent elevated relative mortality and morbidity risks associated with exposure to environmental tobacco smoke.

Insofar as industrial and other blue collar workers are more likely to bring home toxic materials on their person, and also are more likely to smoke than those in other occupations, members of a household are more likely to be subject to paraoccupational exposure and belong to lower socioeconomic strata if the household contains a smoker than if the household does not contain a smoker. Thus observed differences in risk of mortality or morbidity ascribed to ETS on the basis of a comparison of households with and without smokers may be partly or entirely due to differences in paraoccupational exposure and socioeconomic strata. Similarly, differences in mortality and morbidity ascribed to paraoccupational exposure may be partly or entirely due to differences in ETS exposure that are also related to social class and to types of occupation.

A critical examination of OSHA's assessment of risk associated with workplace exposure to environmental tobacco smoke.

In response to a request for information on indoor air quality problems, the U.S. Occupational Health and Safety Administration (OSHA) has proposed a rule addressing indoor air quality in general, and especially environmental tobacco smoke (ETS), in indoor work environments.

Correcting standardized rate ratios for imprecise classification of a polychotomous exposure variable with limited data.

The analysis of exposure misclassification has received considerable attention in the epidemiologic literature, with the result that methods for correcting many summary risk estimates for such misclassification are well known. However, the application of such methods typically requires more data than are usually published (for example, the complete set of exposure- and age-specific mortality rates). The authors show, under the assumption that exposure misclassification occurs independently of disease status and confounder level, that it is possible to obtain estimates of standardized rate ratios corrected for a given pattern of misclassification from only the published standardized risk ratios and the misclassification matrix.

Comments on the Health Effects Institute-Asbestos Research (HEI-AR) report: "Asbestos in public and commercial buildings," with emphasis on risk assessment methods used.

A Health Effects Institute--Asbestos Research Report calculates the risk of exposure to environmental asbestos fibers (EAF) by downward extrapolation from the mortality of workers exposed for 20 years. This extrapolation is improper because 1) relative risks of asbestos exposure very likely are not linearly progressive; 2) the composition of EAF may not be equivalent to that in mining or fabricating; 3) the same environmental asbestos concentration probably represents different exposure doses for different populations; and 4) health effects of asbestos exposure on children, seniors, patients, the institutionalized, the handicapped, and the chronically ill may not be the same as those of healthy workers. Evidence of asbestos-related disease among family members of exposed workers demonstrates that the risk observed for EAF is substantially larger than that estimated from downward extrapolation and suggests a basis for an alternative approach to estimating asbestos-related health risks.

Income, race, and mortality.

This study was undertaken to clarify the complex relationship between poverty and race with disease-specific mortality. Data from the 1987 National Health Interview Survey and the 1986 National Mortality Followback Survey were used to estimate standardized mortality ratios (SMRs) for various categories (all causes, all cancers, noncancerous medical causes, lung and breast cancers, ischemic heart disease, and cerebrovascular disease) associated with income below the poverty line and were compared with those with adequate or better than adequate income. All SMRs were substantially elevated.

The unquiet future of intergenerational politics.

Empirical studies of political opinion and behavior about national issues affecting the aging have not revealed the intergenerational conflicts often predicted in recent decades. Using public opinion studies of attitudes about the aging at the community level in Florida, this study does identify significant cleavages in attitude and belief between generations, suggesting intergenerational political conflict may be likely in the future. The research implies the most important source of this conflict may be the community level and the "image" of the aging that is developing among younger community residents.

Risk attribution and tobacco-related deaths.

The number of deaths that would not have occurred had an exposure or trait been absent is generally estimated by observing mortality rates in sample populations of exposed and nonexposed persons and applying them to the population of interest. Three methods used to estimate deaths due to tobacco use are evaluated. Each method requires estimates of certain absolute and relative risks, and the published estimates based on them assume that the absolute and relative risks observed in the two large American Cancer Society prospective studies can be applied to the US population or to populations in developed countries.

Computation of relative risk based on simultaneous surveys: an alternative to cohort and case-control studies.

If the same information on the distribution of risk factors is available for both the general population and a subset distinguished by some disease outcome, it becomes possible to derive relative risk estimates applicable to the entire population with the assurance that the data upon which the estimates are based is representative of that population. To illustrate this approach, data from the 1986 National Mortality Follow-back Survey and the 1987 National Health Interview Survey were used to compute rate ratios for several causes of death for work in dirtyier as compared with cleaner occupations by three methods commonly employed in cohort and case-control studies: the usual standardized rate ratio, the Mantel-Haenszel estimate of the rate ratio, and a multiplicative model fit to an appropriate cross-classification. Properly placed questions in appropriate surveys might very well serve as a substitute for cohort studies and could be performed at less cost and with less overall effort, and completed in a shorter time.

[Non-typhic Salmonella bacteremias in HIV infections. Clinical and therapeutic data, and course in 68 patients].

Between 1982 and 1989, a retrospective study on non typhi Salmonella bacteremias was performed among patients infected with human immunodeficiency virus hospitalized in 4 departments of Infectious and Tropical Diseases in Paris. The population included 59 men and 9 women; 26.4 percent had been contamined with HIV by heterosexual contact; 17.

Analysis of the relationship between smokeless tobacco and cancer based on data from the National Mortality Followback Survey.

This study investigates the potential link between the use of smokeless tobacco and oral cancer and cancer of digestive organs. The combined data of the National Mortality Followback Survey (NMFS), a probability sample of the U.S.

[Accuracy of risk indicators of the Infant Life Defense Program in a region of the São Paulo State, Brazil].

The Infant Life Defense Program of Health Department of Bauru City SP, Brazil, has diagnostic criteria for the inclusion of newborns. The diagnostic criteria combine eleven social and clinical indices of infant mortality risk, defined by in the light of a review of the literature and previous case studies. The indices are easily collected at the hospitals during delivery.

Bone manifestations associated with acquired immunodeficiency syndrome (AIDS).

To date, descriptions of bone manifestations associated with the acquired immunodeficiency syndrome (AIDS) have mostly been limited to case reports. Six such cases observed in our Departments of Rheumatology and Infectious Diseases, are reported. Three types of manifestations were observed: malignant lymphoma, infectious osteomyelitis, and reflex sympathetic dystrophy syndrome (algoneurodystrophy) secondary to central nervous system involvement.

Bias in the attribution of lung cancer as cause of death and its possible consequences for calculating smoking-related risks.

Most published calculations of mortality risk, especially those for lung cancer associated with smoking, are based almost exclusively on the underlying cause as recorded on death certificates. Such risk calculations implicitly assume that the conditional probability of recording lung cancer as the underlying cause of death, given that it really is the underlying cause, is the same for all exposure groups. If these probabilities are not equal for all exposure groups, we call the resulting bias a cause of death attribution bias.