General outbreaks of infectious intestinal disease linked with salad vegetables and fruit, England and Wales, 1992-2000.

Between 1992 and 2000, 1,518 foodborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC), of which 83 (5.5%) were associated with the consumption of salad vegetables or fruit (SVF). The pathogens most frequently reported were salmonellas (41.0%) and Norwalk-like virus (NLV) (15.7%). In total 3,438 people were affected; 69 were admitted to hospital and one person died. Most outbreaks were linked to commercial catering premises (67.5%). Three community outbreaks, of Salmonella enterica serovar Typhimurium Definitive Phage Type (DT) 104, S. Typhimurium DT 204b and Shigella sonnei infection, were found to be associated with lettuce contaminated at source, and these accounted for 501 (14.6%) cases. The latter two outbreaks were international, involving several European countries. This demonstrates how contamination of SVF during production/processing can result in major, geographically widespread, outbreaks of infection with serious public health consequences.