Contaminated herbs found on Canadian grocery shelves, report concludes
Friday, May 16, 2014
moreguefile photo
by JIM ALGIE
Leafy herbs contaminated with pathogenic microorganisms can be found occasionally in Canadian retail stores and may cause food-borne illness, recently-published, Canadian Food Inspection Agency (CFIA) sampling shows.
Analysis of more than 1,200 samples of Canadian and imported fresh herbs conducted in 2009-2010 yielded salmonella contamination in one case and relatively high levels of generic E. coli in eight others, says the food agency’s May 13 statement.
None of the findings was associated with reported illness. Only one of the problem samples was grown in Canada.
The food agency’s May 13 news release announcing the sampling’s results argues “the vast majority” of leafy herbs sold in Canada “are handled under good agricultural and manufacturing practices.” The release highlights a finding that “more than 98 per cent of fresh leafy herbs sampled . . . were not contaminated with bacterial pathogens . . . and were safe for human consumption.
However, it also warns that “contamination of herbs with bacterial pathogens could sporadically occur.” The agency also advises consumers to follow safety tips published on the Government of Canada’s healthycanadians.gc.ca website which says consumers should wash all fruits and vegetables in running tap water as a precaution.
University of Manitoba microbiologist Rick Holley said problems with leafy herbs and other greens are relatively well known. He commended the agency for its targeted survey but said such research does raise questions about contaminated produce that reaches the market place.
“The real solution to this problem is not to put the bacteria on this type of food product at all,” Holley said in an interview, Thursday. “We have not been very good at that in any of the developed countries,” he said.
Bacterial contamination of leafy vegetables tends to originate with animal manure applied to fields or with non-potable water used as irrigation or post-harvest, wash water, Holley explained.
“CFIA and the associations that are responsible for providing technical advice . . . put a great deal of emphasis on attempting to explain to operating farms and farmers what the real issues are and what needs to be done,” Holley said. “The reality is that there are so many other pressures that the good advice often gets swept under the rug."
Holley is so wary of these hazards that he recommends people avoid pre-cut bagged salads altogether. He recommends buying lettuce as heads or full plants, removing and discarding the outer leaves before cleaning and using interior leaves for salads.
"Washing is not 100 per cent effective; that's the problem," he said.
"There is no fail safe way other than good agricultural practices to address the concern of pathogenic contamination coming from agricultural fields," he added.
"The other thing is to make sure at the farm level that wherever composted manure is being used as a fertilizer make sure it does not contain pathogenic bacteria," Holley said. "We're not doing enough in that area."
The agency’s May 13 release cites a 26-page, Food Safety Action Plan report targeting leafy herbs. That report concludes contaminated, leafy herbs sold in Canada “could be a potential source of food-borne illness.”
Indeed, as recently as May 9, the agency issued a recall of Selection brand rosemary leaves because of possible salmonella contamination although no illness was reported, a check, Thursday, of the agency’s website shows. The rosemary recall was triggered by CFIA test results that were part of a food safety investigation the agency says “may lead to the recall of other products.”
The action plan report is the first to be published in a four-year, microbiology surveillance plan targeting herbs following outbreaks of illness in Canada and Europe. Further results from the surveillance plan are to be released as lab results become available, the statement says.
Researchers tested for generic E. coli, a harmless bacteria that may indicate inadequate sanitation in the processing and handling of produce. They tested also for bacteria implicated directly in human illness: E. coli O 157, salmonella and shigella.
The survey identifies leafy herbs as a priority for surveillance based on past outbreaks of food borne illness and the apparent risks involved. Such produce is often consumed raw and has been implicated in “numerous” incidents of food borne illness in recent years. The United Nations’ Food and Agriculture Organization and the World Health Organization have ranked herbs and other leafy vegetables as “the highest priority . . . in terms of microbiological hazards,” the report says.
The survey included samples collected from retail outlets across the country based on population. Of 1,224 samples collected and analysed, 816 were imported from the United States, Mexico and four other countries, while 408 were produced domestically.
The eight imported samples which tested “unsatisfactory” originated in Mexico, the United States and the Dominican Republic, and included basil, dill, marjoram, oregano and tarragon.
The single example of unsatisfactory, domestic produce occurred in a sample of oregano, the report says.
Investigators followed up on all unsatisfactory samples and initiated one product recall as a result. Survey follow-up work led to the testing of 44 further samples and discovery of salmonella in two additional samples of Mexican mint.
No illness was reported as a result of the contaminated samples, investigators found. However, the results did lead to a review of importation procedures and heightened sampling, the report says.
The survey found elevated E. coli in 10 other samples but at levels below the agency’s standard for “unsatisfactory” produce. None of the 1,224 samples showed E. coli 0157:H7, E. coli 0157:HN or Shigella. BF