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APPENDIX B. Guidelines for Confirmation of Foodborne-Disease Outbreaks

A foodborne disease outbreak (FBDO) is defined as an incident in which two or more persons experience a similar illness resulting from the ingestion of a common food.* The following table provides information about incubation periods, clinical syndromes, and criteria for confirming the etiology once an FBDO has been identified. The information on incubation periods and clinical syndromes is provided as a guideline and should not be included in the confirmation criteria. These guidelines might not include all etiologic agents and diagnostic tests.

FBDOs should be reported to the Foodborne and Diarrheal Diseases Branch at CDC through the Electronic Foodborne Outbreak Reporting System (eFORS) using the web-based Form 52.13, Investigation of a Foodborne Outbreak, which was updated in October 1999. Provision of other documents describing the outbreak investigation also is encouraged. For information about collecting laboratory specimens and for additional information on viral agents, refer to other CDC publications (i.e., Recommendations for collection of laboratory specimens associated with outbreaks of gastroenteritis. MMWR 1990;39[No. RR-14] and Viral agents of gastroenteritis: public health importance and outbreak management. MMWR 1990;39[No. RR-5]).



* Before 1992, three exceptions existed to this definition; only one case of botulism, marine-toxin intoxication, or chemical intoxication was required to constitute an FBDO if the etiology was confirmed. The definition was changed in 1992 to require two or more cases to constitute an outbreak.

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