Scientists: Canada's disease-detection system performed well

Canada’s system that flags outbreaks of food-borne illnesses like listeriosis is the “gold-standard” and does not need any improvements, federal health officials said Thursday. Public Health Agency of Canada officials held a press briefing at Winnipeg’s National Microbiology Lab Thursday afternoon to reassure the public the country’s disease surveillance system detected the listeria outbreak early and responded as quickly as possible.

Dr. Frank Plummer, scientific director general of the Winnipeg-based lab, said the recent outbreak is larger than scientists typically handle, but that lab staff worked around the clock to speed up the amount of time it takes to confirm whether a listeriosis case is linked to tainted meat from Toronto’s Maple Leaf Foods. Most provincial labs, with the exception of Quebec, forward human cases of listeriosis to the National Microbiology Lab to do complex DNA testing to “fingerprint” the bacteria. The fingerprint is then entered in a federal database which flags any cases of food-borne illness with the same DNA, which confirms they are linked. It typically takes federal scientists between ten and fifteen days to extract DNA from bacteria like listeria, but Plummer said scientists have recently sped that up to between four and five days.

Plummer said it would be nearly impossible to process lab results any faster, and that “information is shared immediately” with Health Canada and Canadian Food Inspection Agency officials. “This system that we have in place, this virtual laboratory, shortens the time it takes to detect the problem that has slipped through the system,” Plummer said. “We get food recalls happening much quicker and many cases of illness are prevented.”

The briefing comes on the heels of questions surrounding Canada’s food inspection policy and the government’s response to the listeriosis outbreak.

At least thirteen Canadians have died from listeria bacteria linked to contaminated deli meats, and other deaths are still under investigation. A 67-year-old man from Sioux Valley Dakota Nation was taken to Brandon Hospital last week after he fell ill from listeriosis, but officials have yet to confirm whether his case is connected with the Maple Leaf Foods outbreak.

The bacteria can incubate for up to seventy days in the body, and an infected person may not experience immediate symptoms. Dr. Celine Nadon, head of PulseNet Canada, the electronic database that links all provincial public health laboratories, said scientists flagged a cluster of listeriosis cases in mid-August and have tested 200 listeria samples since June. She said test results on more listeriosis cases are still pending, but would not say how many. “It performed very well,” Nadon said of the testing system.