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Food Safety Risk Assessment

Khaitsa, Margaret; Logue, Catherine
North Dakota State University
Start date
End date
The study will investigate how deliberate contamination of a production line may result in the transfer of a pathogen along a production line and how current processing practices reduce or fail to reduce the risk of contamination. The study will assess cost-effective intervention strategies that could be implemented to further improve the safety of the finished product and develop methods to effectively communicate this risk to key individuals associated with poultry processing i.e. processors, producers etc. In addition, psychological factors such as tiredness and lack of interest will be evaluated to determine how these factors ultimately contribute to risk. The data generated from this study will add to the knowledge currently being generated in risk assessment and will have a significant impact for food safety and the processing industry not only in the US, but worldwide.

Objectives are outlined as follows:

  1. Design a pathway diagram to highlight potential areas of adulteration where impact would be greatest.
  2. Determine the population numbers and types of Salmonella spp. found at points of uncertainty (decision nodes) and how they could be used as indicators of process control or loss.
  3. Evaluate strategies for communication accuracy and efficiency related to risk in food processing.
  4. Evaluate psychological factors that prevent intentional contamination in a production facility.
  5. Estimate the economic impact and cost-effective management strategy of unintentional versus intentional contamination on the poultry industry and the US.
  6. Use the information obtained from objectives 1 to 5 together to:
    Evaluate the likelihood of a deliberate adulteration event at each decision node and the economic consequences of each adulteration point identified.
    Assess cost-effective risk mitigation strategies by determining points along the production line where the implementation of intervention strategies will have the greatest impact on risk reduction.
    Build a producer-friendly simulation model that producer groups can use to incorporate preventative food safety measures which will be useful in evaluating the economic potential of up-streaming and securing production control in the food chain, to ensure security of the food supply to avoid risk associated with deliberate contamination, thus monopolizing value-added processing opportunities.
    Use the data obtained to continue building our database and model which will be made available to other researchers working in risk analysis and assessment. The information from the study will be used to address avoidance in relation to deliberate contamination.
    Aim to strengthen the nation's agricultural work force and partner with our fellow researchers, educators, and stakeholders in addressing the FS risk assessment expertise gap. Specifically, we intend to develop a course and a conference in food safety risk assessment, and then, to share this course and conference with our students and researchers at various locations using HQIV over I2.
More information
NON-TECHNICAL SUMMARY: There is little information on the risk of human illness in the food supply should a deliberate act of terrorism occur. This study will test a previously developed risk assessment model for robustness and how the system could be enhanced to ensure the security and safety of the food supply.

APPROACH: Approaches to the objectives are outlined as described below
1) This objective will be used to design the decision tree and evaluate critical areas on the production line where deliberate contamination of poultry meat with Salmonella spp. would be of greatest risk. This objective will involve complete design of a decision tree (event tree) for the production line in order to evaluate critical points where deliberate contamination could occur.
2) This portion of the study will examine the microbiological levels and incidence of Salmonella spp. occurring at the critical points determined from Obj 1. In addition, evaluation of the best sampling techniques will be examined to evaluate alternative methods which will allow greater sensitivity in the recovery of contaminants. This study will also evaluate current control procedures used in the plant and model them on a laboratory scale to determine how reduction in pathogens occurs and what alternative strategies could be implemented to further reduce pathogens of concern using methods such heat, chlorine etc in an effort to identify indicator sites on the line which could be used to indicate loss of control.
3) This objective will cover the following areas in relation to risk communication. Studies will be carried out to effectively create a communication model for the production plant that is designed to assist poultry and other processing companies in acquiring appropriate information related to safeguarding against bioterrorism.
4) An investigation of psychological factors that can prevent intentional (deliberate) contamination of food based upon the premise that food production workers can have a large impact on the prevention of food contamination. Two models of the workers' actions on the production line will be developed to explain how workers can prevent contamination as well as promote food safety in general.
5) A stochastic production function will be estimated with dummy variables for alternative prevalence level (low prevalence, average or normal prevalence, high prevalence and extremely high prevalence -intentional contamination of Salmonella in turkey processing. The estimated production function will be used to derive elasticities of alternative prevalence levels, cost and profit implications at the industry /state levels. Derived elasticities will facilitate estimation of potential unintentional impacts.
6) Use the information obtained from objectives 1-5 together to determine
a) Microbial Quantitative Risk Assessment
b) Determine Optimum Cost-effective Intervention Strategies c) HQIV for Risk Assessment and Education

PROGRESS: 2003/06 TO 2006/06
Microbiological studies evaluated sampling methods for the detection of pathogens on large birds and recommended whole carcass swabbing procedures. We examined the prevalence and molecular profiles of Salmonella in poultry processing to understand the effect of processing on selection and reduction in Salmonella and have highlighted points where control is greatest. We have investigated the use of real time PCR and multiplex PCR for rapid detection and characterization of Salmonella in naturally contaminated meats. Mutli locus sequence typing (MLST) and Pulsed Field Gel Electrophoresis (PFGE) were used for typing of Salmonella typhimurium and it was found that MLST alone failed to provide adequate discrimination of Salmonella. Epidemiological studies have evaluated foodborne outbreaks in the US (1990-2003) noted seasonal occurrence of illness and turkey as a vehicle ranked last, with outbreaks associated with restaurants and private homes. Causal serotypes identified indicated that S. enteritidis was the most common. In similar studies for ND, turkey also ranked as the least common food associated with salmonellosis. Evaluation of syndromic surveillance was useful as an early detection tool for disease outbreak. The psychologists examined risk in relation to intention and motivated behavior models of food safety and security; how the intention model could be reformulated to consider intentional contamination; expansion of the motivated behavior model considering work habits and routines facilitating actions contributing to food safety; examination of how feedback about normative beliefs could change workers perceptions about pursuing food safety; examine how prevention and promotion strategies influence food safety. Surveys of plant personnel demonstrated that the intention model had application for protecting against intentional contamination. Our economists have evaluated the consequential financial loses/gains and cost effective strategies for reducing risk. These included evaluation of human factors and their impact; implementation of economic optimality for reducing risk in poultry processing; methods for predicting losses in processing and the incentives associated with HACCP implementation. These models have focused on strategies to optimize processing conditions without adversely impacting viability of the organization. Our risk communications group has focused on issues related to communications and its influence on strategies for enhancing the safety of the food supply, including perceptions of risk, communication of risk messages in processing facilities, and strategies for bioterrorism events at various levels including production, consumer and organizational. This group has also developed associations with the National Center for Food Protection and Defense to investigate reliability and messaging for food safety and biosecurity. We have disseminated the data from this project, including the organization of the first ever integrated risk conference held in 2006. Papers from the conference are to be published in Foodborne Pathogens and Disease. We have graduated 8 MS and PhD students.

IMPACT: 2003/06 TO 2006/06
Data obtained from the various studies has enhanced our current knowledge of risk and our studies of risk in relation to deliberate adulteration; we have investigated effective control methods and communication strategies and understanding of means to mitigate risk. We have developed the first ever integrated risk meeting to diseminate our research and have graduated research students.

Funding Source
Nat'l. Inst. of Food and Agriculture
Project source
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Project number
Accession number
Bacterial Pathogens
Risk Assessment, Management, and Communication
Meat, Poultry, Game