A widespread outbreak of Yersinia pseudotuberculosis O:3 infection from iceberg lettuce

Show full item record

Permalink

http://hdl.handle.net/1975/833

Citation

Journal of Infectious Diseases. 2004. 189: 766-774

Title: A widespread outbreak of Yersinia pseudotuberculosis O:3 infection from iceberg lettuce
Author: Nuorti, J.P.; Niskanen, T.; Hallanvuo, S.; Mikkola, J.; Kela, E.; Hatakka, M.; Fredriksson-Ahomaa, M.; Lyytikäinen, O.; Siitonen, A.; Korkeala, H.; Ruutu, P.
ISSN: 0022-1899
Abstract: Background. The vehicles and sources of Yersinia pseudotuberculosis infection are unknown. In Finland, clinical microbiology laboratories routinely report Y. pseudotuberculosis isolations and submit isolates for serotype analysis. In October 1998, the number of serotype O:3 infections increased markedly. Methods. Case patients with culture-confirmed Y. pseudotuberculosis O:3 infection were identified by use of laboratory-based surveillance. We conducted a population-based case-control study. Healthy community control subjects were matched by age, sex, and postal code. Isolates were subtyped by pulsed-field gel electrophoresis (PFGE). Results. Nationwide, 47 case patients were identified (age range, 277 years; median, 19 years). One patient with bacteremia died; 5 underwent appendectomies. We enrolled 38 case patients and 76 control subjects in the case-control study. Seventy-one percent of case patients and 42% of control subjects reported having eaten iceberg lettuce (matched odds ratio, 3.8; 95% confidence interval, 1.39.4); a dose-response relationship was found for increasing frequency of consumption. Of the 27 isolates obtained from case patients and tested in the analysis, all had indistinguishable PFGE patterns. Four lunch cafeterias that had served iceberg lettuce were associated with clusters of case patients. The lettuce was traced back to originating farms. Conclusions. Iceberg lettuce was implicated as the vehicle of a widespread foodborne Y. pseudotuberculosis outbreak. Ongoing laboratory-based surveillance and serotype analysis were essential in the rapid detection of infection. Cases of yersiniosis, which appear to be sporadic, may be part of unrecognized outbreaks caused by contaminated fresh produce.
URI: http://hdl.handle.net/1975/833
Date: 2004


Files in this item

Total number of downloads: Loading...

Files Size Format View
UCP2004.pdf 302.2Kb PDF View/Open

This item appears in the following Collection(s)

Show full item record