Enteric disease: A major health concern in Canada

Despite efforts to reduce the presence of dangerous pathogens in Canadian food and water, Salmonella, E. coli, Campylobacter, Yersinia, Listeria, Shigella, Vibrio, Cryptosporidium, Cyclospora, Giardia, Norovirus, Rotavirus, and others continue to cause gastrointestinal, or enteric, disease in Canada.

Traditional passive surveillance systems, which rely on a patient to report their illness to their doctor and submit a stool sample, have resulted in the under-reporting of enteric disease in Canada (and internationally).

• According to the Public Health Agency of Canada’s National Studies of Acute Gastrointestinal Illness (NSAGI), estimates of under-reporting were developed based on a survey done in Hamilton, Ontario.  It was found that about 1 in 313 cases of enteric disease are reported to the province through passive disease notification surveillance.¹
• For each case of verotoxigenic E. coli reported to Canada's national surveillance system it is estimated that there are approximately 10 to 47 cases in the community, based on findings from the NSAGI studies. 
• Likewise, it is estimated that there are between 13 and 37 cases of Salmonella and 23 to 49 cases of Campylobacter in the community for each reported case.²
• On average, symptoms for most enteric illnesses last approximately 4 days. ^{1, 3, 4}
• Approximately 12 to 24 percent of people with enteric illness in Canada seek medical care.^{3, 4, 5}

 

Most cases of enteric disease are mild and require only a day or two of reduced activities. However, these cases pose a significant burden due to lost productivity and other related costs. Other cases are severe and can result in hospitalization, serious chronic conditions or death.

How do we capture the true burden of enteric disease in our communities and help inform efforts to improve food and water safety in Canada?

In 2005, C-EnterNet was launched in one sentinel site to help answer this question. C-EnterNet is designed based on the U.S. Centers for Disease Control and Prevention’s FoodNet, which has been operating in the United States since 1995 to deliver active surveillance of enteric diseases across the country and to help to inform source attribution (determining what proportion of human cases can be linked back to specific sources, such as a particular food product or contaminated water or contact with animals, for example). Currently, C-EnterNet is running in two sentinel sites.

C-EnterNet’s comprehensive and integrated surveillance system focuses on active surveillance of human cases of illness, coupled with monitoring possible sources of illness in food, animals, and water. The information gathered helps us better understand long-term trends of enteric disease and develop Canadian-specific source attribution estimates. C-EnterNet will help to answer important questions about source attribution; for example, how much salmonellosis in Canada is caused by certain food types versus others. These objectives are being addressed not only in Canada and the United States, but at the international level as governments strive to improve the safety of our food and water supplies.

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