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What is in your bag of frozen berries? The science sleuths at CFIA take a closer look

It's easy to ignore the details behind the food we eat: where it was made, by whom and how safe it is. As long as it looks good on Instagram, we assume it's safe to chow down. It's only when food recalls happen that the safety of our food is propelled into the spotlight, making those with even the most adventurous palette second guess the foods they love. A common reason for a food-related illness is as simple as not following cooking instructions or not cleaning food before it is consumed. Other times, even the best personal food handling practices can't prevent an illness. When people start getting sick, the scientific sleuths at the Canadian Food Inspection Agency's (CFIA) laboratories jump into action.

You may be aware of CFIA announcing outbreaks and recalls to the public. Among them was a norovirus outbreak in 2017 that was linked to frozen berries. It was the team of scientific detectives at the CFIA's Saint-Hyacinthe laboratory, or St-Hy, as it is known, that got to the bottom of the bag.

The food mystery started in March 2017, when small clusters of a norovirus outbreak were found in seniors residences in Quebec. With suspicions that the outbreak was food related, Quebec's food safety department, the Ministère de l'agriculture, des pêcheries et de l'alimentation du Québec (MAPAQ), contacted the CFIA, home to St-Hy, one of the  few laboratories in Canada able to effectively test for foodborne viruses . Since viruses do not easily multiply outside of a host, without food or a human for a virus to live off of, a virus will simply fail to multiply, making molecular techniques for detection of viral parts the only option. For illnesses like these, provincial and territorial partners will sometimes request the CFIA's support to test large quantities of food during illness investigations. This huge quantity makes the analysis much more complicated than a detective show would imply. Nevertheless, the science sleuths at St-Hy got down to business and took action to investigate the source of the food poisoning with MAPAQ.


Several bags of frozen berries arrived at the CFIA's laboratory in Saint-Hyacinthe in early June. Scientists immediately began testing them, using methods developed at CFIA's Food Virology National Reference Centre (FVNRC) located at the St-Hy's laboratory. These methods included looking for tell-tale viral molecules. Within a few days of arriving at the Reference Centre, scientists confirmed that the berries carried norovirus, a common stomach bug. This led CFIA to issue a total of 14 recalls between June 20 and August 21, 2017, for the berries, as well as other products, such as yogurt, mousse, cakes and other pastries.

From March to August that year, 724 cases of norovirus were reported to health authorities in Quebec. The actual number of people who became sick is likely much higher, since not all cases of food poisoning are reported. But teamwork and collaboration helps to contain the spread of illness.

What happened next?

Learning from this outbreak and others is an important step for CFIA to uphold food safety standards. After the successful provincial-federal collaboration, an agreement was signed giving four MAPAQ analysts the opportunity to visit St-Hy for a three-day training session on CFIA foodborne virus investigations, equipment, laboratory layout and best practices. The CFIA's St-Hy continues to support foodborne virus-related illness investigations to strengthen response readiness in Canada.

Is it safe to eat?

Taking the plunge (or the bite) requires trust that the food on our shelves is safe to eat. While sometimes looks can be deceiving, especially on social media, scientists at CFIA use more than just pretty pictures to ensure the safety of Canadian food. The experts use the latest tools, and often develop new ones, based on molecular and genetic detection methods to track down disease-causing agents. The work done by scientists helps keep all of us safe. The public also has a key role to play in being safe; through safe food handling and preparation as well as staying connected with the CFIA for up-to-date information and recalls so they can ensure that the food on their plate is both Instagram-worthy AND stomach-worthy.

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