Fact Check: What you might not know about E. coli
Published Sunday, October 7, 2012 6:30AM EDT
Canada’s biggest-ever beef recall has been a wake-up call for many Canadians, who may not have given a lot of thought to where their beef comes from. Many have been surprised to learn just two companies– XL Foods and Cargill -- process over 90 per cent of the cattle in this country.
That’s prompted some consumers to consider buying from a local butcher or farmer. But is it safer? How about organic beef? Some answers from a food sciences expert.
Is beef from a local farm safer than from a big grocery chain?
Buying beef from a farmer in your area is a great idea if you want to support the local economy. But if you think it’s eliminating your risk of an E. coli infection, you’re mistaken.
Keith Warriner, an associate professor in the Department of Food Science at University of Guelph notes that E. coli can be found in the lower digestive tract of cows who live anywhere in the country. While it’s true an E. coli outbreak at a small slaughterhouse will likely affect fewer customers than from a larger plant, the overall risk is still about the same, he says.
“I know when we have these outbreaks there are people who say local farm or organic farms are better. But it’s not really true,” he tells CTVNews.ca. “There’s an equal chance of meat getting contaminated in a small abattoir as in a big abattoir. There’s no data that suggests otherwise.”
E. coli typically enters a slaughterhouse from manure that can get stuck on the cow’s hide. It can also contaminate slaughterhouse equipment and enter the meat when the intestines are nicked during removal of the organs from the carcass. Those methods of transmission don’t change whether it’s a small, local slaughterhouse or one of the large processing plants.
Is beef from cows that feed on grass safer than corn feed?
There have been a few studies that suggested that grain-fed animals were more likely to carry E. coli than grass-fed. But Warriner says there have been other, more recent studies that have contradicted those findings, suggesting there really isn’t any difference.
“And when you think about it, there is no reason why there should be any difference. E. coli resides in the rectum of cattle, not in their stomachs. Once their feed gets to the lower GI tract, there is no reason for the bacteria to be any different.”
I have some of the recalled meat. If I cook it really well, will I be fine?
Are you sure you really want to take that chance – especially with the recalled ground beef?
First of all, Warriner says, a lot of home chefs get it wrong when they try to judge whether their meat is fully cooked based on its colour. Ground beef has to be cooked to an internal temperature of 160 degrees F or 71 Celsius and the only way to be sure is to use a food thermometer – a step that many Canadians fail to take.
Even cooking potentioally contaminated whole meats, like steaks, might not be safe. While it’s true that only the outside surface needs to be cooked well to kill off the bacteria, there is still a chance you will cross-contaminate your kitchen with E. coli along the way, just by touching your cutting board, your sink faucet, the knob on your stove or your dish towels. E. coli is remarkably resilient and can live on these surfaces for a long time, just waiting to get passed around.
Warriner says you’d be surprised how little E. coli is needed to make you sick: just 10 cells if you’re a child, a senior, pregnant or someone with a chronic illness. For healthy adults, it might take 1,000 cells.
“To put that in perspective, a pinhead could contain about 1 million E. coli cells. So it’s very, very virulent,” says Warriner.
I know someone who had E. coli and they ended up being fine. Why the fuss?
Escherichia coli are a large group of bacteria. Some strains are harmless, others can make you sick, others can you make you very, very sick.
Yes, most adults will fully recover from an E. coli O157:H7 infection. But during the five to 10 days of a typical illness, they could have everything from severe stomach cramps to violent vomiting to bloody diarrhea. It’s no picnic.
For children and the immuno-compromised, the danger is of course much more severe. Ten per cent or so of all those infected with E. coli can develop complications that will shut down their kidneys -- a condition called hemolytic uremic syndrome. Some don’t survive and even those who do often live with permanent kidney damage or require a kidney transplant.