Purpose: Describe the frequency and characteristics of multistate foodborne outbreaks attributed to raw tomatoes.
Methods: We reviewed outbreaks, defined as ≥2 persons with a similar illness, reported to CDC’s Foodborne Disease Outbreak Surveillance System from 1973-2010. Tomato-associated multistate outbreaks were defined as those resulting from raw tomato consumption in more than one U.S. state or territory. We analyzed demographics, pathogens, geographic distribution, seasonality, tomato type, and contamination source.
Results: From 1973-2010, 15 multistate outbreaks were attributed to raw tomatoes, resulting in a reported 1,952 laboratory-confirmed illnesses (median 86 per outbreak, range 8-429), 384 hospitalizations, and 3 deaths. Most outbreaks (80%) were reported from 2000-2010, and 73% occurred May-September. Thirty-seven states (median 9 per outbreak, range 2-24), predominantly in the eastern U.S., were affected. Outbreaks commonly affected adult (median age 34 years, range <1-97 years) women (58%). All outbreaks were caused by Salmonella [serotypes Newport (6 outbreaks), Braenderup (2), Baildon, Enteritidis, Javiana, Montevideo, Thompson, Typhimurium (1 each); one outbreak included multiple serotypes]. Red round (69%), Roma (23%), and Grape (8%) were the tomato types reported. Although 87% of outbreaks were associated with tomatoes served predominantly at restaurants, all reports suggested that contamination likely occurred during production in growing fields, at packinghouses, or at fresh processing (e.g., slicing) facilities located mainly in the southeastern U.S. Only one outbreak resulted in a recall of raw tomatoes.
Significance: Multistate outbreaks attributed to raw tomatoes were large, widespread, and increasingly recognized and reported. Public health interventions should focus on reducing Salmonella contamination early in tomato production — on the farm, in packinghouses, and during repacking and fresh processing.