Revised Estimates of the Burden of Foodborne Illness in Canada

Introduction: Foodborne illness estimates help set food safety priorities and create public health policies. In 2008, the Public Health Agency of Canada estimated that 11 million episodes of foodborne illness occur each year in Canada. Although the best estimate at the time, it was determined using older methods and data. The Public Health Agency of Canada recently completed revised estimates of foodborne illness for Canada.

Purpose: There were two overall objectives: (1) calculate a more accurate estimate of domestically, acquired foodborne illness in Canada using current data and more robust methods and (2) identify knowledge gaps for further research.

Methods: Estimates for 30 known pathogens and unspecified agents using data from Canadian surveillance systems (for years 2000-2010), relevant international literature and the 2006 Canadian census population were calculated. The analysis accounted for under-ascertainment as public health surveillance systems are subject to under-reporting and under-diagnosis. Estimates on the proportion foodborne and the proportion travel-related were incorporated for each pathogen. Monte Carlo simulations were performed to account for uncertainty using @Risk software generating mean estimates and 90% credible intervals.

 Results: There are an estimated 4.0 million episodes of domestically acquired, foodborne illness each year in Canada (1.6 million episodes from 30 known pathogens and 2.4 million episodes from unspecified agents). The top four pathogens are (1) norovirus, (2) Clostridium perfringens, (3) Campylobacter spp. and (4) non-typhoidal Salmonella spp.

Significance: The revised estimates cannot be compared for trends with the 2008 estimate because different methods were used. Although lower, the revised estimates are more accurate than the 2008 estimate because they use current data and more rigorous methods.

Policy makers, industry, academia and other organizations can use the revised estimates to better inform policy, research, food safety risk assessments, education campaigns and other prevention and control activities – ultimately improving the health of Canadians.