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Biomedical subjects

M D McElvaine

Publications and source records attributed to M D McElvaine.

10 recordsLinked to original sources
PubMed1997

Long-term sequelae to foodborne disease.

Most of the concern about foodborne disease has been focused on the immediate effects of acute infection. Recent information has shown that many of these foodborne infections also have long-term sequelae with serious health effects and a significant economic impact. To increase the awareness of animal health professionals to these sequelae, the authors discuss two groups of sequelae which are strongly associated with preceding infection (reactive arthritides, including Reiter's syndrome, and the Guillain-Barré syndrome) as well as the possible association between Crohn's disease and Mycobacterium paratuberculosis. The discussion includes a description of the disease syndromes along with epidemiological and economic information. More reliable epidemiologial and economic data on chronic sequelae to foodborne disease will be needed for future evaluation of the cost-effectiveness of mitigation strategies to reduce the occurrence of foodborne pathogens.

Animals↗
PubMed1995

Risk analysis systems for veterinary biologicals: a regulator's tool box.

Recent advances in biology and technology have significantly improved our ability to produce veterinary biologicals of high purity, efficacy and safety, virtually anywhere in the world. At the same time, increasing trade and comprehensive trade agreements, such as the Uruguay Round of the General Agreement on Tariffs and Trade (GATT: now the World Trade Organisation [WTO]), have put pressure on governments to use scientific principles in the regulation of trade for a wide range of products, including veterinary biologicals. In many cases, however, nations have been reluctant to allow the movement of veterinary biologicals, due to the perceived threat of importing an exotic disease. This paper discusses the history of risk analysis as a decision support tool and provides examples of how this tool may be used in a science-based regulatory system for veterinary biologicals. A wide variety of tools are described, including qualitative, semi-quantitative and quantitative methods, most with a long history of use in engineering and the health and environmental sciences.

Animals↗
PubMed1995

Risk of introducing exotic disease through importation of animals and animal products.

Between 1870 and 1929, nine separate outbreaks of foot and mouth disease (FMD) occurred in the United States of America (USA); additional outbreaks in North America include one in Mexico (1947) and two in Canada (1870 and 1952). In 1930, the United States Congress enacted a law prohibiting importation of live ruminants or swine or fresh meat from these species into the USA from countries affected with FMD or rinderpest. Although the effect of this prohibition may be debated, the USA has remained free of FMD since its enactment. A hidden benefit of this prohibition was probably the limitation on importing other disease agents from countries of the world where FMD was present. As many regions of the world make progress towards the control and eradication of FMD, North America must take greater cognizance of other disease agents with which it has not been concerned to date, as these existed only in regions of the world affected with FMD and/or rinderpest. One of the methods of dealing with these other diseases is by using risk assessment and risk management methodologies. For risk assessment to work, however, the available management technologies must be examined, and levels of risk assigned to match the available technology. The authors explore risk analysis options for the importation of animals and animal products in a manner which will continue to protect the livestock industry in the USA. They also examine the role of veterinary biologicals as a management tool to mitigate the attendant risks.

Animal Diseases↗
PubMed1994

Long-term trends in blood lead levels among children in Chicago: relationship to air lead levels.

OBJECTIVES: To evaluate trends in blood lead levels among children in Chicago from 1968 through 1988, and to determine the impact of the changes in the Centers for Disease Control and Prevention (CDC) blood lead level of concern. METHODS: We reviewed a systematic sample of blood lead screening records of the Chicago Department of Health Laboratory for high-risk children aged 6 months to 5 years. Median blood lead levels for each quarter of the years 1974 through 1988 were determined and regressed against mean air lead levels recorded at air-monitoring stations in Chicago during the same period. RESULTS: Median blood lead levels declined from 30 micrograms/dL in 1968 to 12 micrograms/dL in 1988, and were strongly associated with declining average air lead levels (r = .8, P < .001) from 1974 through 1988. A regression model using log-transformed data predicted a decline of 0.56 microgram/dL in the median blood lead level with each 0.1 microgram/m3 decline in the mean air lead level when the air lead level was near 1.0 microgram/m3; the predicted slope was steeper at lower air lead levels. Despite the nearly 20-fold reduction in air lead levels, the median blood lead level of 12 micrograms/dL in 1988 indicates substantial continuing lead exposure. The CDC blood lead level of concern was lowered twice from 1968 to 1988, but due to the decline in blood lead levels, fewer than 30% of the children were above the level of concern throughout most of the study. CONCLUSION: Although substantial lead exposure persists in Chicago, reductions in airborne lead emissions seem to have contributed to a long-term decline in the median blood lead level of high-risk Chicago children.

Age Factors↗
PubMed1993

An assessment of the risk of foreign animal disease introduction into the United States of America through garbage from Alaskan cruise ships.

The United States Department of Agriculture, Animal and Plant Health Inspection Service (USDA-APHIS) has been exploring methods of quantitative risk assessment to support decision-making, provide risk management options and identify research needs. With current changes in world trade, regulatory decisions must have a scientific basis which is transparent, consistent, documentable and defensible. These quantitative risk assessment methods are described in an accompanying paper in this issue. In the present article, the authors provide an illustration by presenting an application of these methods. Prior to proposing changes in regulations, USDA officials requested an assessment of the risk of introduction of foreign animal disease to the United States of America through garbage from Alaskan cruise ships. The risk assessment team used a combination of quantitative and qualitative methods to evaluate this question. Quantitative risk assessment methods were used to estimate the amount of materials of foreign origin being sent to Alaskan landfills. This application of quantitative risk assessment illustrates the flexibility of the methods in addressing specific questions. By applying these methods, specific areas were identified where more scientific information and research were needed. Even with limited information, the risk assessment provided APHIS management with a scientific basis for a regulatory decision.

Alaska↗
PubMed1993

Developing a quantitative risk assessment process.

The international animal health community is advocating a more widespread use of quantitative risk assessment in making international trade decisions. In this article, the authors explain why quantitative risk assessment is a valuable tool, outline a process with key steps for developing a quantitative risk assessment, and describe a method for quantifying the uncertainty associated with the results of a risk assessment.

Animal Diseases↗
PubMed1993

Standardization of nomenclature for animal health risk analysis.

The authors propose standard definitions for terms and concepts commonly used in agricultural risk analysis. The differences between risk analysis and risk assessment are explained, and the relationship of these two terms with the more familiar terms "epidemiology" and "biostatistics" is discussed. The authors stress the importance of differentiating words and phrases which share similar sounds but are subtly different, and the necessity of developing a common nomenclature in agricultural risk analysis. An opportunity is provided for readers to comment on the definitions presented.

Agriculture↗
PubMed1992

Prevalence of radiographic evidence of paint chip ingestion among children with moderate to severe lead poisoning, St Louis, Missouri, 1989 through 1990.

Although experts once believed that ingesting chips of lead-based paint was the major cause of lead poisoning among children, conventional wisdom now holds that lead-contaminated dust and soil are the major routes of exposure. Data from a childhood lead-poisoning treatment clinic were examined to assess the frequency with which children ingest paint chips. For this study, the reports on abdominal radiographs of 90 children with moderate to severe lead poisoning who had received their first chelation treatment during 1989 or 1990 were reviewed. According to a radiologist's evaluation, 13 of 90 abdominal radiographs (14%; 95% confidence interval [CI] 7% to 22%) showed evidence of paint chip ingestion. Of 46 children with blood lead levels greater than or equal to 55 micrograms/dL, 12 (26%) had radiographs that showed paint chips, whereas only 1 (2%) of 44 children with blood lead levels less than 55 micrograms/dL had such radiographs (prevalence ratio = 11.5; 95% CI 1.6 to 84.6). The actual proportion of children with moderate to severe lead poisoning who have consumed leaded-paint chips is likely to be higher than this estimate based on radiographic evidence. While lead-contaminated dust is a major source of lead exposure, ingestion of leaded-paint chips clearly remains an important source of exposure among children with moderate to severe lead poisoning.

Acute Disease↗
PubMed1991

Evaluation of the erythrocyte protoporphyrin test as a screen for elevated blood lead levels.

To study the effect of lowering the definition of an elevated blood lead level on the performance of the erythrocyte protoporphyrin screening test and the number of children who would require follow-up, we collected laboratory data from a screening program. The estimated sensitivity of an erythrocyte protoporphyrin level greater than or equal to 35 micrograms/dl for identifying children with elevated blood lead levels was 73% when we used 1985 Centers for Disease Control guidelines (elevated blood lead level greater than or equal to 25 micrograms/dl). Eight percent of the tests showed positive results. When we redefined an elevated blood lead level as greater than or equal to 15 micrograms/dl, the sensitivity estimate was reduced to 37% and the number of positive test results increased fourfold.

Child, Preschool↗