1、Introduction of Hazards: Preparation, Consumption, and the Chain of TransmissionPathogen Reduction Dialogue Panel 1 May 6, 2002 Georgetown University Conference Center,Robert V Tauxe, M.D., M.P.H. Foodborne and Diarrheal Diseases Branch,DBMD, NCID Centers for Disease Control and Prevention,Atlanta,
2、GA,Each year an estimated 76 million cases 1 in four Americans gets a foodborne illness each year 1 in 1000 Americans is hospitalized each year $6.5 billion in medical and other costsPrevention depends on efforts from farm to table to reduce contamination of food,Public health burden of foodborne di
3、sease,Infection with a variety of different pathogensIllness may occur in large focal outbreaks Most illness is “sporadic”: either individual cases or part of unrecognized dispersed outbreaksReservoir: locus of sustained transmission and persistence Some have a human reservoir: Shigella, hepatitis A
4、, Norwalk virusSome have an animal reservoir: Salmonella, Campylobacter,E. coli O157:H7, Listeria, Vibrio, Yersinia, ToxoplasmaOften transmitted by several different pathways Specific foods, water, direct contact with animals, direct contact with humans,Foodborne diseases,Major identified foodborne
5、pathogens, United States circa 2002,Bacterial: Bacillus cereus Brucella Campylobacter* Clostridium botulinum Clostridium perfringens E. coli O157:H7* E. coli, non-O157 STEC* E. coli, other diarrheagenic* Listeria monocytogenes* Salmonella Typhi Salmonella non-typhoidal Shigella Staphylococcus Strept
6、ococcus Vibrio cholerae, toxigenic*,Bacterial, continued: Vibrio vulnificus* Vibrio, other* Yersinia enterocolitica*Parasitic: Cryptosporidium* Cyclospora* Giardia* Toxoplasma* TrichinellaViral: Norwalk-like viruses* Rotavirus* Astrovirus* Hepatitis A,* Recognized as foodborne in last 30 years,Prion
7、s*,Major identified foodborne pathogens, United States circa 2002,Bacterial: Bacillus cereus Brucella Campylobacter* Clostridium botulinum Clostridium perfringens E. coli O157:H7* E. coli, non-O157 STEC* E. coli, other diarrheagenic* Listeria monocytogenes* Salmonella Typhi Salmonella non-typhoidal
8、Shigella Staphylococcus Streptococcus Vibrio cholerae, toxigenic*,Bacterial, continued: Vibrio vulnificus* Vibrio, other* Yersinia enterocolitica*Parasitic: Cryptosporidium* Cyclospora* Giardia* Toxoplasma* TrichinellaViral: Norwalk-like viruses* Rotavirus* Astrovirus* Hepatitis A,* Recognized as fo
9、odborne in last 30 years (Zoonotic reservoir),Prions*,The new foodborne zoonoses,The infected food animal looks healthy Sustained or repeated infections in animals Contaminated food looks normal Pathogen survives standard processingand preparation Missed by current inspection strategies Spreads sile
10、ntly around the globe Requires new control strategiesMore to be discovered,The chain of production from farm to table:A generic scenario,Production,Processing,Final preparation and cooking,Farm, Feedlot, Fishing site,Slaughter Plant, Cannery, Packer, Food Factory,Final Kitchen: commercial, instituti
11、onal or domestic,The chain of production from farm to table:A generic scenario,Production,Processing,Final preparation and cooking,Farm, Feedlot, Fishing site,Slaughter Plant, Cannery, Packer, Food Factory,Final Kitchen: commercial, institutional or domestic,What happens in kitchens?,1993-1997: Amon
12、g 2,751 foodborne outbreaks reported to CDC, 43% in restaurants/delis/etc Contributing kitchen factors noted 73% - poor holding temperatures38% - poor personal hygiene21% - inadequate cooking1980-1995: New York State: 1806 outbreaks: 32% - contaminated ingredients 24% - consumption of raw/lightly he
13、ated 23% - food from unapproved source 23% - ill food handler,Outbreaks are multi-factorial events,Problems in food handling are often reported in foodborne outbreak investigationsProbably frequent in kitchens where an outbreak has not occurredTraining focused on better food handling important, so i
14、s handwashingReducing the arrival of the pathogens into kitchen is also important,Introduction of pathogens into food during final preparation: what are the sources?,Foods arrive contaminated(particularly raw foods of animal origin)Food handler infected with the pathogenOther environmental sources,W
15、hen contaminated raw foods of animal origin arrive in the kitchen,Handling may further amplify riskEasily cross-contaminate other foodsvia hands, utensils, surfacesA direct risk if undercooked (FoodNet 2000 survey) Raw oysters - 2.5% in preceding month Pink ground beef - 26% Runny egg dish - 27% 3%
16、use a thermometer for burgers,When an ill food handler arrives in the kitchen,They work, because they have no paid sick leaveThey may be shedding the organism in feces or vomitLapses in personal hygiene can contaminate foodParticularly for pathogens with human reservoir: Norwalk-like viruses, Shigel
17、la, hepatitis AOccasionally for pathogens with animal reservoirs: Salmonella, E. coli O157, Campylobacter,Food may be contaminated by other environmental sources,Food prepared or consumed around animals Petting zoos, county fairs, “barn dances” Large E. coli O157 outbreak, U Wisconsin, 2001 34 cases
18、 after a breakfast in the stock pavilionFood prepared with contaminated waterRodents, insects, and other vermin may cross-contaminate food,Prevention strategies for the general public to reduce contamination in the kitchen,Basic food safety education Avoid risky food practices Separate handling raw
19、meat and infant care Purchase foods processed for safety: Pasteurized milk, juice Pasteurized shell eggs Irradiated ground beefAsk restaurants about their sick leave policies,Prevention strategies for food establishments to reduce contamination in the kitchen,Basic food safety training and certifica
20、tion Paid sick leave policies Make handwashing easy and frequent Reduce contact with ready to eat foodInclude pathogen reduction standards in purchase contracts,For institutional kitchens serving high risk populations, foods processed for safety are available now,Pasteurized shell eggs and liquid eg
21、gs to avoid Salmonella Enteritidis infectionsIrradiated ground beef to avoid E. coli O157:H7 and Salmonella infectionsFrozen chicken and turkey, to reduce risk of Campylobacter infections,Food safety education is important but not sufficient to protect public health,Raw foods of animal origin are of
22、ten contaminated Serious infections, grave complications Traditional recipes call for limited cooking Raw oysters, rare ground beef, soft boiled eggs, hollandaise sauce Hard to tell when food is thoroughly cooked Boiled eggs, baked lasagna, “browned” burgers Raw meat, poultry, eggs in the kitchen is
23、 handled by someone also handling other foods Fresh produce, rinsed and eaten without cooking,The chain of production from farm to table:Where contamination can occur,Production,Processing,Final preparation and cooking,Feed, water, manure, wildlife, new stock,Lairage, water baths, Manure, sanitation
24、, cross contamination,Time, temperature, Cross-contamination, Worker health, hygiene,Pathogens:Campylobacter E. coli O157:H7 Salmonella YersiniaListeria monocytogenesNorwalk-like viruses Hepatitis A,Sources:Poultry, production level Cattle, production level, Poultry, cattle, pig, produce, production
25、 level Pigs, production levelReady to eat meats, processing levelHumans, production and preparation level Humans, production and preparation level,Principle sources of pathogens,The chain of production from farm to table:Where contamination can occur,Production,Processing,Final preparation and cooki
26、ng,Land Animals,Plants,Fish and shellfish,Meat, poultry, dairy, eggs,Fruits, nuts, vegetables,Seafoods,The chain of production from farm to table:Where contamination can occur with Vibrio parahaemolyticus,Production,Processing,Final preparation and cooking,Land Animals,Plants,Fish and shellfish,Meat
27、, poultry, dairy, eggs,Fruits, nuts, vegetables,Seafoods,Shellfish in their beds,The chain of production from farm to table:Where contamination can occur withNorwalk like viruses,Production,Processing,Final preparation and cooking,Land Animals,Plants,Fish and shellfish,Meat, poultry, dairy, eggs,Fru
28、its, nuts, vegetables,Seafoods,Ill humans,The chain of production from farm to table:Where contamination can occur withzoonotic Salmonella,Production,Processing,Final preparation and cooking,Land Animals,Plants,Fish and shellfish,Meat, poultry, dairy, eggs,Fruits, nuts, vegetables,Seafoods,Carrier f
29、ood animals,The chain of production from farm to table:Prevention possible at many points,Production,Processing,Final preparationand cooking,Pathogen Killing Step,On-farm sanitation, safety of animals food and water biosecurity, and other “Good Agricultural Practices“,Factory sanitation, quality con
30、trol HACCP, microbial verification, inspection and other “Good Manufacturing Processes“,Food handler training, handwashing, sick leave, Restaurant inspection, Consumer education,Pasteurization, retort canning, irradiation,Schematic map of food industry,Production,Processing,Preparation,Land animals,
31、Plants,Seafood,Fish &shellfish,Meat, poultry,dairy,eggs,Fruit, nuts & vegetables,Distribution,Transport/lairage,Consumption (and foodborne illness),HACCP,HACCP,HACCP monitoring samples (FSIS data). Percent of ground beef samples yielding Salmonella, by size of processing plant, and year,Baseline,HAC
32、CP monitoring samples. Percent of broiler, ground turkey and hog samples yielding Salmonella, by year, large processing plants (FSIS data),Human illness data (CDC-FoodNet). Change in incidence of foodborne infections relative to 1996,15% 25% 31%49%,Decrease of,Some future prevention points for foodb
33、orne disease (with microbial validation),Production,Processing,Preparation,Land animals,Plants,Seafood,Fish &shellfish,Meat, poultry,dairy,eggs,Fruit, nuts & vegetables,Distribution,Transport/lairage,Consumption (and foodborne illness),HACCP,HACCP,QAP,Some future prevention points for foodborne dise
34、ase (with microbial validation),Production,Processing,Preparation,Land animals,Plants,Seafood,Fish &shellfish,Meat, poultry,dairy,eggs,Fruit, nuts & vegetables,Distribution,Transport/lairage,Consumption (and foodborne illness),HACCP,HACCP,HACCP,QAP,Foodborne pathogens enter food chain at multiple po
35、ints Pathogen reduction approaches can reduce risk at each step Microbial monitoring can verify control measures In the kitchen: Educating the food preparers is important, so is Handwashing Keeping ill workers out of the kitchen, and Decreasing contamination of food coming into the kitchen Microbial standards in purchase contracts may help For high risk populations, using safer food products,Summary,
