PT - JOURNAL ARTICLE AU - Williams, Robin C. AU - Isaacs, Sandy AU - Decou, Mary Lou AU - Richardson, Elizabeth A. AU - Buffett, M. Catherine AU - Slinger, Robert W. AU - Brodsky, Michael H. AU - Ciebin, Bruce W. AU - Ellis, Andrea AU - Hockin, James AU - , TI - Illness outbreak associated with <em>Escherichia coli</em> O157:H7 in Genoa salami DP - 2000 May 16 TA - Canadian Medical Association Journal PG - 1409--1413 VI - 162 IP - 10 4099 - http://www.cmaj.ca/content/162/10/1409.short 4100 - http://www.cmaj.ca/content/162/10/1409.full SO - CMAJ2000 May 16; 162 AB - Background: An outbreak of Escherichia coli O157:H7 infection was identified in the spring of 1998, with a 7-fold increase in the number of laboratory-confirmed E. coli O157:H7 cases in southern Ontario. This prompted an intensive investigation by local, provincial and federal public health officials. Methods: Case interviews of 25 people from southern Ontario were conducted using a broad food history and environmental exposure survey. Laboratory investigations involved both case and food sampling. Specimens of foods sold locally and reportedly consumed by those affected were tested. Common suppliers of suspected foods were identified by cross-referencing suppliers' lists with stores frequented by those who fell ill. A case-control study involving 25 cases and 49 age-matched controls was conducted. This was followed by a comprehensive environmental investigation of the meat processing plant identified as the source of the E. coli. Results: Thirty-nine outbreak-related cases occurred between April 3 and June 2, 1998. Of the 36 case specimens tested all were positive for E. coli O157:H7. The case-control study identified Genoa salami as the most probable (odds ratio 8 [confidence interval 2-35]) source of the outbreak. Samples of Genoa salami produced by the most commonly identified supplier later tested positive for E. coli O157:H7, and the pathogen matched the same pulsed-field gel electrophoresis pattern and phage type of the case specimens. Interpretation: Our investigation, which led to a national recall of the brand of dry fermented Genoa salami identified as the source of the outbreak, supports an adherence to stringent manufacturing requirements for fermented meat products. A review of the Canadian standards for fermented meat processing and the effectiveness of their implementation is warranted.