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Outbreaks attributed to fresh leafy vegetables, United States, 1973–2012

  • K. M. HERMAN (a1), A. J. HALL (a1) and L. H. GOULD (a1)

Leafy vegetables are an essential component of a healthy diet; however, they have been associated with high-profile outbreaks causing severe illnesses. We reviewed leafy vegetable-associated outbreaks reported to the Centers for Disease Control and Prevention between 1973 and 2012. During the study period, 606 leafy vegetable-associated outbreaks, with 20 003 associated illnesses, 1030 hospitalizations, and 19 deaths were reported. On average, leafy vegetable-associated outbreaks were larger than those attributed to other food types. The pathogens that most often caused leafy vegetable-associated outbreaks were norovirus (55% of outbreaks with confirmed aetiology), Shiga toxin-producing Escherichia coli (STEC) (18%), and Salmonella (11%). Most outbreaks were attributed to food prepared in a restaurant or catering facility (85%). An ill food worker was implicated as the source of contamination in 31% of outbreaks. Efforts by local, state, and federal agencies to control leafy vegetable contamination and outbreaks should span from the point of harvest to the point of preparation.

Corresponding author
* Author for correspondence: Dr L. H. Gould, 1600 Clifton Rd, NE MS-C09, Atlanta, GA 30333, USA. (Email:
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Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
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