Food Safety Microbiology - February, of 27 Quantitative Risk Assessment Don Schaffner, Ph.D. Rutgers, The State University of NJ

Food Safety Microbiology - February, of 27 Overview -How does risk analysis relate to risk assessment? -How is risk assessment applied to food microbiology? -A very simple example of a quantitative risk assessment -Web links and more information

Food Safety Microbiology - February, of 27 Risk Analysis Components -(Quantitative) Risk Assessment How big is the risk, what factors control the risk? Scientific process -Risk Communication How can we talk about the risk with affected individuals? Social and psychological process -Risk Management What can we do about the risk? Political process

Food Safety Microbiology - February, of 27 Cartoon

Food Safety Microbiology - February, of 27 Step in Risk Assessment -Hazard Identification What microbe, food(s) and people are involved? -Exposure Analysis What is the chance of exposure? How many cells? -Dose-Response Analysis What is the human health effect of the exposure? -Risk Characterization Complete picture of the assessed risk

Food Safety Microbiology - February, of 27 Hazard Identification -Epidemiological data linking Foods Pathogens Human illness -Special considerations Disease complications Acute vs. chronic disease Specific sensitive consumer populations Characteristics of the organism Organisms mode of action

Food Safety Microbiology - February, of 27 Exposure Analysis -Estimate likelihood of consumption likely number (dose) of the pathogen -If “quantitative” assessment Modeling Simulation

Food Safety Microbiology - February, of 27 Exposure - Simple Example -Initial number of organisms follows a Poisson distribution -Growth rate is normally distributed -Product composition and storage temperature are fixed -The product becomes unsafe when it contains 100,000 organisms/gram

Food Safety Microbiology - February, of 27 Initial number - Poisson

Food Safety Microbiology - February, of 27 Growth rate is normal

Food Safety Microbiology - February, of 27 Simulation Results

Food Safety Microbiology - February, of 27 Dose-Response Analysis Translates exposure analysis output in to a measure of human health If “quantitative” Use dose-response curve Estimate probability of infection and illness from dose

Food Safety Microbiology - February, of 27 Dose response curve Cassin et al. Quantitative risk assessment for Escherichia coli O157:H7 in ground beef hamburgers. Int.J.Food Micro. 41 (1):21-44, 1998.

Food Safety Microbiology - February, of 27 Dose-Response factors -Statistical model(s) to analyze or quantify dose- response relationships Threshold vs. non-threshold models -Dose response data Human Animal Outbreak or intervention data

Food Safety Microbiology - February, of 27 Dose-Response factors -Source and preparation of challenge material or inoculum -Organism type and strain Virulence factors or other measures of pathogenicity -Characteristics of the exposed population Age, immune status, etc.

Food Safety Microbiology - February, of 27 Risk Characterization -Final task in risk assessment -Combines the information from Hazard identification Exposure analysis Dose-response analysis -Produces a complete picture of the assessed risk

Food Safety Microbiology - February, of 27 A good risk assessment… -Is… Transparent Iterative -Includes… Variability and uncertainty Management input into problem formulation

Food Safety Microbiology - February, of 27 A hot-air balloon floats overhead… RM: I’m lost, can you tell me where I am? RA: Sure, you are 30 feet off the ground RM: Aha, you must be a risk assessor RA: Why yes, how did you know? RM: Because what you told me was technically correct, but of absolutely no use.

Food Safety Microbiology - February, of 27 A hot-air balloon floats overhead… RA: Aha, you must be a risk manager? RM: Why yes, how do you know? RA: That’s easy, you don’t know where you are, what you want or where you are going… and you are in the same position now as you were before you asked for my help, but now it’s my fault!

Food Safety Microbiology - February, of 27 Importance of risk assessment -Teaching Students can see “what if...” -Research Pinpointing uncertainties or knowledge gaps -Industry Optimizing safety while retaining quality -Government Designing regulations for the greatest benefit

Food Safety Microbiology - February, of 27 For more information -Annotated bibliography on Food Safety Risk Assessment, Management and Communication mhttp:// m -Food Safety Risk Analysis Clearinghouse come.htmhttp:// come.htm

Food Safety Microbiology - February, of 27 For more information -Revised Framework for Microbial Risk Assessment – ILSI -WHO/FAO microbial risk analysis page dex.htmhttp:// dex.htm

Food Safety Microbiology - February, of 27 Software -USDA Pathogen Modeling -Crystal ball -Analytica

Food Safety Microbiology - February, of 27 Books -T. A. McMeekin, et al. Predictive microbiology: Theory and application, Somerset, England:Research Studies Press Ltd., C.H. Haas, et al. Quantitative microbial risk assessment, Ny, NY: John Wiley & Sons, D. Vose. Risk Analysis: A Quantitative Guide, Chichester:John Wiley & Sons, 2000.

Food Safety Microbiology - February, of 27 Published risk assessments -S. enteritidis in eggs -Listeria in RTE foods -Fluoroquinolone Resistant Campylobacter in Chicken es.htmhttp:// es.htm

Food Safety Microbiology - February, of 27 Published risk assessments -Vibrio in shellfish -E.coli O157:H7 in ground beef htmhttp:// htm -Campylobacter in chicken rse/annac/index.htmlhttp:// rse/annac/index.html

Food Safety Microbiology - February, of 27 Cartoon