How risk assessors and risk managers have utilized available data to support decision making Listeria and Vibrio Risk Assessment Examples Risk Assessment Consortium Data Collection and Utilization in Risk Assessment and Management Decisions Richard Whiting CFSAN
A risk assessment is what you do when the data are less than ideal
Finding data for a risk assessment is a lot like a scavenger hunt
Ideal solution for data quality and utility Conduct preliminary quantitative risk assessment Identify critical data gaps (quality, utility) Collect data Complete risk assessment
Relevancy ~ Data Utility Uncertainty
Relevancy How pertinent is this data to this particular risk assessment? Survey studies Place Time
Geographic and temporal factors for V. parahaemolyticus LocationSeasonHarvest pathogenic V.p/g oyster Percentage pathogenic V.p. Gulf Coast-- Louisiana Winter (n=5) Summer4.5 Mid-AtlanticWinter0.0061N.D. (TDH+ like GC, n=1) Summer1.5 NE-AtlanticWinter0.006N.D. (TDH+ like GC, n=1) Summer0.42 Pacific NWWinter (n=2) Summer0.022
CDC FoodNet and NFPA Contamination Data NFPA 2003 (% positive retail) FoodNet 2002 (cases per 100,000 people per year) Seafood Salad Soft Cheese StateL. m.Campy.E.c. O157:H CA MD GA OR MN
Treatment of Lm Contamination Data Weight by number of samples Weight by year (≤1993, 94-98, ≥ 99: 0.4, 0.7, 1.0) Weight by country US, developed countries, importing countries vs others (1.0, 0.3) No recent data Adjust by total food supply data Food Category % positive pre-1999/ % all years High fat dairy 0.9 Soft ripened cheese 1.8 Deli meats3.4
Relevancy of microbial data Always a question Strains used, selectivity/specificity of methods Lab/pilot plant ~ commercial Composition of product 17 growth in deli meat data sets included Corned beef Cooked ham Vacuum packed ham Bologna Sliced chicken/turkey Turkey loaf Cooked chicken Roast beef Growth in franks with lactate-diacetate not included
Uncertainty Should be added to data Home storage time (d) FoodMinimumMost likelyMaximum Smoked Seafood Soft ripened cheese Dry, ferm. sausages
Home storage times for refrigerated frankfurters and deli meats —AMI survey, 2001 Average timeFraction 1 to 3 days to to to to to to > Storage time
Three dose-response models for V. p. fitted to data Mean Ingested Dose (cfu) Probability of Gastroenteritis Human Feeding Trials Data Probit Gompertz Beta-Poisson
Uncertainty for V.p. Dose-response Beta Poisson Model Probability of Illness Mean Dose (log cfu per Exposure)
Uncertainty and Data Quality 2-way Risk assessment
Low variation, low uncertainty
High variation, low uncertainty
Low variation, high uncertainty
High variation, high uncertainty
Data Quality and Utility Are data good enough for the RM to use the RA to reach a conclusion or are the uncertainties too great? Total Cases Listeriosis per Annum (log scale) DM PM HFDFNR SUC P CRUM SS F FR V DFS FSC SSC SRC DS RS PF IC PCCDHC Listeriosis cases per year