A descriptive study of verocytotoxigenic Escherichia coli (VTEC) cases reported in Ontario, 1990-1994

Characteristics of VTEC cases identified through routine surveillance in Ontario between 1990 and 1994 are described. Information was extracted from the Reportable Disease Information System (RDIS) of Ontario and was evaluated for its completeness and internal validity. A total of 2,441 VTEC cases were identified for the five-year study period corresponding to an average annual rate of 4.8 cases per 100,000. Sixteen deaths were recorded. Bloody diarrhea was reported for 546 patients (40%) and was the most frequently reported symptom. For most cases, the home was recorded as the likely risk setting (36%). Food was incriminated as the source of infection for more than 36% of cases. Nine (69%) of the thirteen data fields compulsory for transmission to the Ontario Ministry of Health had less than 10% of combined missing and unspecified values. Fields describing risk factors had greater than 56% of entries missing or unspecified.