Following the lead of the U.S., Canada has significantly reduced its estimate of annual foodborne illness rates – the number of people barfing each year from food – from 11 million to 4 million, or 1-in-8 people each year.
The current U.S. estimate is 48 million annual cases or 1-in-6 people, down from 76 million or 1-in-4 people.
The Public Health Agency of Canada estimates that each year roughly one in eight Canadians (or four million people) get sick due to domestically acquired food-borne diseases. This estimate provides the most accurate picture yet of which food-borne bacteria, viruses, and parasites (“pathogens” – why the dick fingers?) are causing the most illnesses in Canada, as well as estimating the number of foodborne illnesses without a known cause.
In general, Canada has a very safe food supply; however, this estimate shows that there is still work to be done to prevent and control foodborne illness in Canada, to focus efforts on pathogens which cause the greatest burden and to better understand foodborne illness without a known cause.
The Agency has estimates for two major groups of foodborne illnesses:
Known foodborne pathogens: There are 30 pathogens known to cause foodborne illness. Many of these pathogens are tracked by public health systems that monitor cases of illness.
To estimate the total number of food-borne illnesses, the Agency estimated the number of illnesses caused by both known foodborne pathogens and unspecified agents.
In general, to be captured in a Canadian surveillance system a sick individual must: seek care; have a sample (stool, urine or blood) requested; and submit a sample for testing. In addition, the sample must be tested with a test capable of identifying the causative agent; and finally the positive test result must be reported to the surveillance system. Surveillance systems only capture a small portion of total illnesses given all these necessary steps (i.e. there is under-diagnosis and under-reporting taking place).
The Agency’s 2013 estimates of illnesses from food-borne diseases in Canada are more accurate than the estimates published in 2008 of 11 million episodes of foodborne illness each year based on better data and methodologies. The 2008 estimates used values from earlier United States Centers for Disease Control and Prevention estimates applied to a Canadian estimate of the average number of episodes of acute gastrointestinal illness per person occurring each year. In addition, the methodology used for the 2013 estimates is different from that used in 2008. As a result of these differences, no strict side-by-side comparison can be made between the two sets of estimates. The 2013 estimates do not mean that there is less foodborne illness occurring, but rather, that more accurate estimates are now possible.
Estimates of the burden of foodborne illness in Canada for 30 specified pathogens and unspecified agents, circa 2006
Foodborne Pathogens and Disease
M. Kate Thomas, Regan Murray, Logan Flockhart, Katarina Pintar, Frank Pollari, Aamir Fazil, Andrea Nesbitt, and Barbara Marshall
Estimates of foodborne illness are important for setting food safety priorities and making public health policies. The objective of this analysis is to estimate domestically acquired, foodborne illness in Canada, while identifying data gaps and areas for further research. Estimates of illness due to 30 pathogens and unspecified agents were based on data from the 2000–2010 time period from Canadian surveillance systems, relevant international literature, and the Canadian census population for 2006. The modeling approach required accounting for under-reporting and underdiagnosis and to estimate the proportion of illness domestically acquired and through foodborne transmission. To account for uncertainty, Monte Carlo simulations were performed to generate a mean estimate and 90% credible interval. It is estimated that each year there are 1.6 million (1.2–2.0 million) and 2.4 million (1.8–3.0 million) episodes of domestically acquired foodborne illness related to 30 known pathogens and unspecified agents, respectively, for a total estimate of 4.0 million (3.1–5.0 million) episodes of domestically acquired foodborne illness in Canada. Norovirus, Clostridium perfringens, Campylobacter spp., and nontyphoidal Salmonella spp. are the leading pathogens and account for approximately 90% of the pathogen-specific total. Approximately one in eight Canadians experience an episode of domestically acquired foodborne illness each year in Canada. These estimates cannot be compared with prior crude estimates