Foodborne Illness Outbreaks and Sprouts

1. Foodborne Illness Outbreaks and Sprouts FDA Public Meeting: 2005 Sprout Safety May 17, 2005 Amy Dechet, M.D. Foodborne and Diarrheal Diseases Branch Centers for Disease Control and Prevention, Atlanta, GA

2. Annual Burden of Foodborne Illness in the United States 76 million illnesses 325,000 hospitalizations 5,000 deaths Mead et.al., 1999, EID

3. What Does This Really Mean? • 76 million cases annually means: • 1 in 4 Americans ill • 1 in 1000 Americans hospitalized • ≥ $6.5 billion in medical and other costs

4. Foodborne Outbreak Surveillance • Local and state health departments • Detect, investigate, and control outbreak • CDC • Collect reports: # of cases, implicated food, etiology • Define an outbreak: • 2 or more cases of a similar illness resulting from the ingestion of a common food • Reporting • Voluntary and incomplete

5. Foodborne Outbreaks Reported to CDC, 1990 - 20031 Enhanced surveillance 1 By states to the Foodborne Disease Outbreak Surveillance System

6. Produce Associated Outbreaks Reported to CDC 1998-2002* • 249 outbreaks • 6% of outbreaks with reported food source • 13% of outbreak-associated cases • Implicated produce • Generic or multiple: 144 outbreaks • Lettuce: 22 • Sprouts: 14 • Juice: 10 • Melon: 9 • Tomato: 8 • Berries: 6 • Other produce: 36 67% of outbreaks with single vehicle (*Preliminary information)

7. Produce Item, Outbreaks, Consumption Produce# outbreaks% population eating item (1998-2002) (FoodNet Survey 2002) • Lettuce 22 73% • Sprouts 14 8% (“stealth” vehicle) • Juice 10 26-65% • Melon 9 21-28% • Tomato 8 68% • Berries 6 21-33%

8. Sprouts: Where Does Contamination Occur? • Multiple opportunities for contamination from farm to table • Field: grazing animals • Mixing: same harvest machinery and processing facilities • Scarification: bacteria enters seed • Transport: many steps along the way

9. Sprouts: Bacterial Growth, Detection, and Elimination • Sprouting: warm, moist environment perfect for bacterial growth • 2-4 log increase in CFU/gram • Difficult to detect pathogens • Non-homogenous distribution • Low-level contamination • Rarely washed or cooked by consumer

10. Sprouts: Why They Are Unique • Multiple pathogens implicated in outbreaks • Salmonella: Typhimurium, Mbandaka, Saintpaul, Muenchen, Enteritidis, Kottbus, Chester, Cubana, Bovismorbificans • E. coli: O157:H7, O157:non-motile • Multiple kinds of sprouts • alfalfa, mung bean, clover, broccoli, etc. • International partners

11. Sprout Outbreaks by Year

12. Alfalfa Sprout Outbreaks by Year(N=26)

13. Alfalfa Sprout Outbreaks by Year FDA advises chlorination of seeds

14. Alfalfa Sprout Outbreaks and Compliance with FDA Guidelines by Year FDA advises chlorination of seeds

15. Average Size Outbreak by Year

16. Produce Item, Outbreaks, Consumption Produce# outbreaks% population eating item (1998-2002) (FoodNet Survey 2002) • Lettuce 22 73% • Sprouts 14 8% (“stealth” vehicle) • Juice 10 26-65% • Melon 9 21-28% • Tomato 8 68% • Berries 6 21-33%

17. Apple juice or cider Orange juice Lemonade Other juice Using Outbreaks to Observe the Effect of Interventions: Juice-Associated Outbreaks, 1994-2004* Juice Labeling reg Juice HACCP reg *National foodborne outbreak reporting system, 2004 data preliminary

18. Conclusions • Sprout-associated outbreaks represent a small proportion of foodborne outbreaks • Sprouts are one of the most common vehicles identified in produce-associated outbreaks • Current practices are not adequate to prevent disease from sprouts • Outbreak surveillance offers opportunities for tracking effectiveness of interventions

19. Thank you!

20. Alfalfa Sprout Outbreaks and Consumption by Month