Pork Implicated in a Shiga Toxin-producingEscherichia coliO157:H7 Outbreak in Ontario, Canada

Objectives:To describe an outbreak of Shiga toxin-producingEscherichia coli(STEC) O157:H7 infection following a four-day family gathering in Ontario. This is the first published account of a STEC O157 outbreak in Canada linked to consumption of pork. Methods:The outbreak investigation included interviews with food handlers and other key associated persons, inspection of food preparation premises, traceback investigations, case finding, analysis of data from an outbreak questionnaire, and laboratory analysis of samples collected from various sources associated with the outbreak. Results:Several meals, including pork from a pig roast, were served to the 59 attendees, 29 of whom developed gastrointestinal illness following the event. Six cases developed bloody diarrhoea and seven were hospitalized. Leftover pork served the day after the pig roast was the item most significantly associated with an increased risk of illness (p