Comparing listeriosis risks in at-risk populations using a user-friendly quantitative microbial risk assessment tool and epidemiological data.

Although infection by the pathogenic bacterium Listeria monocytogenes is relatively rare, consequences can be severe, with a high case-fatality rate in vulnerable populations. A quantitative, probabilistic risk assessment tool was developed to compare estimates of the number of invasive listeriosis cases in vulnerable Canadian subpopulations given consumption of contaminated ready-to-eat delicatessen meats and hot dogs, under various user-defined scenarios. The model incorporates variability and uncertainty through Monte Carlo simulation.

Evidence for horizontal and vertical transmission in Campylobacter passage from hen to her progeny.

Campylobacter is an important human pathogen, and consumption of undercooked poultry has been linked to significant human illnesses. To reduce human illness, intervention strategies targeting Campylobacter reduction in poultry are in development. For more than a decade, there has been an ongoing national and international controversy about whether Campylobacter can pass from one generation of poultry to the next via the fertile egg.

Scientific and technical factors affecting the setting of Salmonella criteria for raw poultry: a global perspective.

Concerns about foodborne salmonellosis have led many countries to introduce microbiological criteria for certain food products. If such criteria are not well-grounded in science, they could be an unjustified obstacle to trade. Raw poultry products are an important part of the global food market.

Probabilistic risk model for staphylococcal intoxication from pork-based food dishes prepared in food service establishments in Korea.

Foodborne illness contracted at food service operations is an important public health issue in Korea. In this study, the probabilities for growth of, and enterotoxin production by, Staphylococcus aureus in pork meat-based foods prepared in food service operations were estimated by the Monte Carlo simulation. Data on the prevalence and concentration of S.

Modeling and risk assessment for Salmonella in meat and poultry.

Microbial risk assessment is rapidly becoming a well-recognized concept in the management of food- and waterborne microbial hazards. The process of conducting a risk assessment is a structured, systematic approach to integrate and evaluate information from diverse sources concerning the origin and fate of pathogens along the food chain and to determine the magnitude of public health risks. Quantitative modeling of the sources, prevalence, numbers, and behavior of food chain pathogens, such as Salmonella, and of the host/pathogen interaction and consequences are providing scientific information and insights useful for decision makers in managing the safety of the food supply.

Campylobacter spp. in Icelandic poultry operations and human disease.

We describe the observed relationship of campylobacter in poultry operations to human cases in a closed environment. During 1999 in Iceland, domestic cases of campylobacteriosis reached peak levels at 116/100,000 and in 2000 dropped to 33/100,000. Approximately 62% of broiler carcass rinses were contaminated with Campylobacter spp.

A risk analysis framework for the long-term management of antibiotic resistance in food-producing animals.

In recent years, there has been increasing concern that the use of antibiotics in food-producing animals, particularly their long-term use for growth promotion, contributes to the emergence of antibiotic-resistant bacteria in animals. These resistant bacteria may spread from animals to humans via the food chain. They may also transfer their antibiotic-resistance genes into human pathogenic bacteria, leading to failure of antibiotic treatment for some, possibly life-threatening, human conditions.

A probabilistic analysis of Clostridium perfringens growth during food service operations.

The purpose of this study was threefold: first, the study was designed to illustrate the use of data and information collected in food safety surveys in a quantitative risk assessment. In this case, the focus was on the food service industry; however, similar data from other parts of the food chain could be similarly incorporated. The second objective was to quantitatively describe and better understand the role that the food service industry plays in the safety of food.

Crohn's disease and Mycobacterium avium subsp. paratuberculosis: current issues.

Crohn's disease is a chronic debilitating inflammatory bowel disease of unknown etiology. Proposed causes include bacterial or viral infection, diet or exposure to tobacco smoke, genetic abnormality, and immune dysfunction. The bacterium Mycobacterium avium subsp.

A descriptive analysis of giardiasis cases reported in Ontario, 1990-1998.

Cases of giardiasis in Ontario were described using notifiable disease data from the Ontario Ministry of Health for the years 1990-1998 inclusive. The mean annual age- and sex-adjusted incidence rate was 25.77 cases per 100,000 population for the 25,289 cases reported.

[Project for supporting visually handicapped aged persons: developing a guide for the community of Münster].

In this paper we wish to outline both the function and the role of projects as part of a course in "Nursing Education" (Pflegepädagogik) at the Fachhochschule Münster, as well as to present a specific project which has enabled the students to gain experience in project management and qualitative research. The project target group were visually handicapped old people for whom a guide was produced as a health promotion strategy within the framework of governmental health objectives in the state of Northrhine-Westfalia.

Hazard identification and exposure assessment for microbial food safety risk assessment.

The four cornerstones of microbial food safety risk assessment are hazard identification, exposure assessment, hazard characterization, and risk characterization. These steps represent a systematic process for identifying adverse consequences and their associated probabilities arising from consumption of foods that may be contaminated with microbial pathogens and/or microbial toxins. This paper presents a discussion of the first two steps: hazard identification and exposure assessment, and considerations for different approaches that can be used to analyze the relevant information.

Survival of listeria innocua in salmon following cold-smoke application.

The ability of Listeria innocua to survive on salmon fillets during cold smoking in a commercial processing plant was investigated using a central composite rotatable response surface design to examine smoking temperatures in the range of 18 to 30 degrees C and a smoke time from 2 to 14 h. Smoke temperature did not significantly (P < 0.05) reduce counts of L.

Pre-slaughter control of Escherichia coli O157 in beef cattle: a simulation study.

A stochastic simulation model was used to assess the benefit of measures implemented in the pre-slaughter period that are aimed at reducing the contamination of beef carcasses with Shiga-like-toxin-producing Escherichia coli O157. The scenario studied was based on an abattoir processing approximately 1000 head of lot-fed cattle per day. Input assumptions were described using probability distributions to reflect uncertainty in their true values.

A simulation model for studying the role of pre-slaughter factors on the exposure of beef carcasses to human microbial hazards.

A Monte Carlo simulation model was constructed for assessing the quantity of microbial hazards deposited on cattle carcasses under different pre-slaughter management regimens. The model permits comparison of industry-wide and abattoir-based mitigation strategies and is suitable for studying pathogens such as Escherichia coli O157:H7 and Salmonella spp. Simulations are based on a hierarchical model structure that mimics important aspects of the cattle population prior to slaughter.

Reliability of an ordinal rating system for assessing the amount of mud and feces (tag) on cattle hides at slaughter.

A study was conducted to provide a quantitative description of the amount of tag (mud, soil, and bedding) adhered to the hides of feedlot beef cattle and to appraise the statistical reliability of a subjective rating system for assessing this trait. Initially, a single rater obtained baseline data by assessing 2,417 cattle for 1 month at an Ontario beef processing plant. Analysis revealed that there was a strong tendency for animals within sale-lots to have a similar total tag score (intralot correlation = 0.

Simulation modeling for microbial risk assessment.

Quantitative microbial risk assessment implies an estimation of the probability and impact of adverse health outcomes due to microbial hazards. In the case of food safety, the probability of human illness is a complex function of the variability of many parameters that influence the microbial environment, from the production to the consumption of a food. The analytical integration required to estimate the probability of foodborne illness is intractable in all but the simplest of models.

Quantitative risk assessment for Escherichia coli O157:H7 in ground beef hamburgers.

Quantitative Risk Assessment (QRA) is a methodology used to organize and analyze scientific information to estimate the probability and severity of an adverse event. Applied to microbial food safety, the methodology can also help to identify those stages in the manufacture, distribution, handling, and consumption of foods that contribute to an increased risk of foodborne illness, and help focus resources and efforts to most effectively reduce the risk of foodborne pathogens. The term Process Risk Model (PRM) is introduced in this paper to describe the integration and application of QRA methodology with scenario analysis and predictive microbiology to provide an objective assessment of the hygienic characteristics of a manufacturing process.

Quantitative risk assessment: an emerging tool for emerging foodborne pathogens.

New challenges to the safety of the food supply require new strategies for evaluating and managing food safety risks. Changes in pathogens, food preparation, distribution, and consumption, and population immunity have the potential to adversely affect human health. Risk assessment offers a framework for predicting the impact of changes and trends on the provision of safe food.

An Overview of Microbial Food Safety Risk Assessment .

This is an overview of the application of risk assessment for evaluating and managing foodborne microbiological health risks. Risk assessment comprises four steps: hazard identification, hazard characterization, exposure assessment, and risk characterization. The process provides a framework for systemic and objective evaluation of all available information pertaining to the foodborne hazard.

Analysis of whole-cell fatty acid profiles of verotoxigenic Escherichia coli and Salmonella enteritidis with the microbial identification system.

Differentiation of strains within bacterial species, based on gas chromatographic analysis of whole-cell fatty acid profiles, was assessed with 115 strains of verotoxigenic Escherichia coli and 315 strains of Salmonella enteritidis. Fatty acid-based subgroups within each of the two species were generated. Variability of fatty acid profiles observed in repeat preparations from the same strain approached that observed between subgroups, limiting the usefulness of using fatty acid profiles to subgroup verotoxigenic E.

Determination of virulence of different strains of Listeria monocytogenes and Listeria innocua by oral inoculation of pregnant mice.

A pregnant mouse model was developed to follow the course of infection after peroral inoculation with six different strains of Listeria monocytogenes and one strain of Listeria innocua. Tissues were sampled and analyzed by microbiologic and histologic methods for 5 days postinoculation. In gnotobiotic pregnant BALB/c mice, L.

Evaluation of enrichment procedures for recovering Listeria monocytogenes from dairy products.

Six different enrichment media and five selective plating media were compared for their suitability for the recovery of Listeria monocytogenes from dairy products. These included media used to test milk products by the U.S.

Occurrence and significance of streptococci in fermented Italian type dry sausage.

Commercial cultures used in Canada for the manufacture of Italian dry sausage were examined to determine their microbial composition and suitability for low temperature (less than or equal to 20 degrees C) meat fermentations. Temperature optima in both laboratory media and commercial meat mixtures were generally too high to allow these cultures to be of substantial advantage in this application. In addition, media used currently for the enumeration of streptococci and related organisms from fermented meat products were found to be inadequately specific and often required confirmatory inspection of colonies by conventional phase contrast microscopy.