Food: It Shouldn’t Be a Mystery

1. Food: It Shouldn’t Be a Mystery Alan M. Tart Regional Retail Food Specialist U.S. Food and Drug Administration Atlanta, GA

2. Objectives • Name several examples of chemical, physical, and biological hazards found in food • Review principles of microbiological growth & survival • Identify at least one nutritional risk in food • Discuss how to prevent, eliminate, or reduce hazards/risks of concern

3. Foodborne Illness in the U.S.

4. The Problem – Foodborne Illness • Estimated 76 million illnesses • 325,000 hospitalizations annually; hospital stays estimated at more than $3 billion • and 5,000 deaths! Mead et al., Emerg. Infect. Dis. 5:607-625

5. Factors Affecting Foodborne Illness in the U.S. • Globalization of the food supply • Food consumption patterns • Methods/Surveillance/ Awareness • Changing production and processing practices • Evolution of new strains • Increased longevity

6. Controlling Food Safety Hazards

7. Hazard A physical, chemical, or biologicalproperty that may cause an unacceptable consumer health risk.

8. Physical Hazards • Poor handling procedures in the food flow • Examples: plastic, bones, wood, glass, metal fragments,

9. Naturally Occurring Chemical Hazards • Scombrotoxin • Ciguatera Toxin • Shellfish Toxins • Tetrodotoxin • Toxic Mushrooms • Allergens

10. Biological Hazards • Includes bacterial, viral, and parasitic organisms Dennis Kunkel

11. Percentage of Foodborne Illness Attributable to Known Pathogens Mead et al., 1999

12. Bacteria, Viruses, and Parasites – What’s the Difference? • Bacteria grow in food and in the body • Bacterial Infection vs. Intoxication • Viruses and parasites cannot grow in food, only in the body.

13. Factors Needed for Bacterial Growth • Food • Acidity • Time • Temperature • Oxygen • Moisture – Available Water

14. Oxygen Requirements of Bacteria Aerobic Facultative Anaerobic Oxygen Dependent Oxygen Intolerant

15. Vegetative Bacteria • Found on many raw animal foods (meat, fish, eggs, milk), as well as processed foods • Examples • Salmonella • E. coli O157:H7 • Listeria monocytogenes • Vibrio spp. • Control Measures • Cooking • No bare hand contact with RTE food • Handwashing • Not working when ill • Temperature control

16. Staphylococcus aureus • High numbers of cells produce heat stable toxin in ready-to-eat food • Caused by bare hand contact with ready-to-eat food and temperature abuse • Poor competitor on raw foods • Normal reheating will not destroy toxin

17. Bacterial Spore Formation • Spore – survival mechanism for certain bacteria • Heat resistance exceeds normal cooking temperatures • Spore-forming organisms • C. perfringens • C. botulinum • B. cereus • Control Measures • Proper cooling • Hot and cold holding

18. Clostridium botulinum • Proteolytic strains of Type A and B will not grow below 10°C (50°F) • Non-proteolytic strains of type B and E will not grow below 3.3°C (38°F) • C. botulinum will not grow at a water activity of 0.94 or less

19. Recent Botulism Outbreaks • Most cases of botulism are due to home-prepared foods • Nearly all of the recent botulism outbreaks due to commercial foods are the result of extreme temperature abuse of refrigerated foods (2 or more days at room temperature) • Outbreaks due to commercially processed low acid canned foods are rare

20. Recent Botulism Outbreaks • Refrigerated pasta sauce in a plastic pouch in a cardboard carton • Refrigerated bean dip in a 16 oz plastic tub with a snap fit lid • Garlic in oil • Sautéed onions left in a warm skillet overnight • Frozen shredded potato patty • Refrigerated carrot juice in a plastic bottle • Baked potato wrapped in foil

21. Foodborne Viruses • Hepatitis A • 83,000 cases (5% foodborne) • Noroviruses • Formally known as Norwalk-like viruses • 23M cases (40% foodborne) • Noroviruses are the #1 cause of foodborne illness in the U.S. (67%) • Example outbreaks • Other viruses F.P. Williams, U.S. EPA Mead et al., 1999

22. Viruses and Cooking • Viruses display variable resistance to heat • Important controls • No bare hand contact with ready-to-eat food • Proper handwashing • Not preparing food when ill

23. Why Viruses are Such a Problem • 10,000,000 - # of viral particles you start with in 1 ml of feces • 1,000,000 - # of virus particles left after properly washing your hands (2 log reduction) (Ayliffe et al., 1978) • 100,000 - # of virus particles transferred from an ungloved hand to food (10%) (Montville, 2001) • In contrast, it takes ~10 virus particles to make you sick

24. Behavioral Causes of Foodborne Illness

25. Foodborne Illness Risk Factors • Food from Unsafe Sources • Inadequate Cooking • Improper Holding Temperatures • Contaminated Equipment/Cross Contamination • Poor Personal Hygiene

26. Food from Unapproved Source

27. Food from Unapproved Source

28. Food from Unapproved Source

29. Unapproved Cheese Product

30. CDC’s EHS NET OUTBREAK/ NONOUTBREAK STUDY - Contributing Factors Identified in Outbreaks,EHS-NET, 2002-2003 C- Contamination Factors P- Proliferation Factors S- Survival Factors Infected Person Handling Food Bare Hand Contact Holding Food at Room Temperature Cross Contamination from Raw Animal Food Insufficient Time/Temp. During Initial Cooking Raw Food Contaminated at Source

31. Nutritional Risks in Food

32. Nutritional Risk in Food • Obesity epidemic • Genetic causes • Environmental causes • Health risks associated with obesity

33. Questions? Alan M. Tart Regional Retail Food Specialist U.S. Food and Drug Administration 60 8th Street, N.E. Atlanta, GA 30309 Alan.Tart@fda.hhs.gov (404) 253-1267