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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
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A risk assessment is what you do when the data are less than ideal
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Finding data for a risk assessment is a lot like a scavenger hunt
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Ideal solution for data quality and utility Conduct preliminary quantitative risk assessment Identify critical data gaps (quality, utility) Collect data Complete risk assessment
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Relevancy ~ Data Utility Uncertainty
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Relevancy How pertinent is this data to this particular risk assessment? Survey studies Place Time
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Geographic and temporal factors for V. parahaemolyticus LocationSeasonHarvest pathogenic V.p/g oyster Percentage pathogenic V.p. Gulf Coast-- Louisiana Winter0.0920.36 (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 NWWinter0.00082.6 (n=2) Summer0.022
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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:H7 2.22.0 CA 0.3731.71.0 7.20.5 MD 0.436.70.5 GA 0.187.60.7 OR 0.2616.05.1 MN 0.1019.03.6
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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
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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
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Uncertainty Should be added to data Home storage time (d) FoodMinimumMost likelyMaximum Smoked Seafood 0.53 - 515 - 30 Soft ripened cheese 0.56 - 1015 - 45 Dry, ferm. sausages 0.56 - 1045 - 90
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Home storage times for refrigerated frankfurters and deli meats —AMI survey, 2001 Average timeFraction 1 to 3 days0.32 4 to 7 0.37 8 to 10 0.06 11 to 14 0.04 15 to 210.01 22 to 300.01 31 to 600.01 > 600.00 1020 30 0 Storage time
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Three dose-response models for V. p. fitted to data 0.000001 0.0001 0.00001 0.001 0.01 0.1 1 Mean Ingested Dose (cfu) Probability of Gastroenteritis Human Feeding Trials Data Probit Gompertz Beta-Poisson
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Uncertainty for V.p. Dose-response Beta Poisson Model Probability of Illness Mean Dose (log cfu per Exposure) 6810124 0.8 0.6 0.4 0.2 0.0 1.0
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Uncertainty and Data Quality 2-way Risk assessment 6 - 10 15 - 45
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Low variation, low uncertainty
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High variation, low uncertainty
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Low variation, high uncertainty
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High variation, high uncertainty
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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? -5 -4 -3 -2 0 1 2 3 4 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
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