Research article2008Peer reviewed
A large Escherichia coli O157 outbreak in Sweden associated with locally produced lettuce
Soderstrom, A.; Osterberg, P.; Lindqvist, A.; Jonsson, B.; Lindberg, A.; Ulander, S. Blide; Welinder-Olsson, C.; Lofdahl, S.; Kaijser, B.; De Jong, B.; Kuhlmann-Berenzon, S.; Boqvist, S.; Eriksson, E.; Szanto, E.; Andersson, S.; Allestam, G.; Hedenstrom, I.; Muller, L. Ledet; Andersson, Y.
Abstract
In 2005 a large outbreak of verotoxin-producing Escherichia coli (VTEC) occurred in Sweden. Cases were interviewed and cohort and case-control studies were conducted. Microbiological investigations were performed using polymerase chain reaction (PCR) to detect the Shiga-like toxin (Stx) genes followed by cultivation and pulsed-field gel electrophoresis. A total of 135 cases were recorded, including 11 cases of hemolytic uremic syndrome. The epidemiological investigations implicated lettuce as the most likely source of the outbreak, with an OR of 13.0 (CI 2.94-57.5) in the case-control study. The lettuce was irrigated by water from a small stream, and water samples were positive for Stx 2 by PCR. The identical VTEC O157 Stx 2 positive strain was isolated from the cases and in cattle at a farm upstream from the irrigation point. An active surveillance and reporting system was crucial and cooperation between all involved parties was essential for quickly identifying the cause of this outbreak. Handling of fresh greens from farm to table must be improved to minimize the risk of contamination.
Published in
Foodborne Pathogens and Disease
2008, Volume: 5, number: 3, pages: 339-349
Publisher: MARY ANN LIEBERT INC
UKÄ Subject classification
Food Science
Publication identifier
DOI: https://doi.org/10.1089/fpd.2007.0065
Permanent link to this page (URI)
https://res.slu.se/id/publ/21123