High levels of Escherichia coli, better known as E. coli, showed up on recent tests of three West Vancouver beaches, so swimmers have been advised to find other bodies of water in which to cool off. The bacterium is a common source of food poisoning, and it’s just one of several organisms that can wreak havoc on people’s digestive systems.
According to the B.C. Centre for Disease Control, 1,400 people in the province get sick from food-borne illness every day.
Summertime can be especially bad for food poisoning because bacteria can multiply quickly in hot weather.
Summer activities like camping and barbecuing can also put people at greater risk. Campylobacter jejuni, one of the leading causes of bacterial foodborne diarrheal disease worldwide, for instance, can be found in rivers, streams, and lakes near where animals graze.
“People who do a lot of backcountry hiking or camping and drink out of a stream may think, ‘Oh, it’s pristine mountain water,’ when, in fact, it’s contaminated by feces of an animal,” says Claudia Kurzac, Vancouver Coastal Health’s manager of environmental health, in a phone interview. “It [C. jejuni] is also associated with undercooked poultry.”
In fact, the consumption of chicken and chicken products has been implicated in recent years in a large number of outbreaks of acute campylobacteriosis worldwide, in both industrialized and developing countries, and especially in children, the elderly, and immunosuppressed patients, according to a study published in Frontiers of Microbiology in 2011.
Shellfish harvested from campylobacter-contaminated water can sicken people too.
Symptoms of campylobacteriosis include diarrhea that’s often bloody or watery, abdominal pain, fever, nausea, and sometimes vomiting. Most people develop symptoms within two to five days of exposure, though symptoms can appear upwards of 10 days or, occasionally, a month after infection.
“It can be very challenging to figure out where you might have been exposed to contaminated water and food,” Kurzac says. “After 10 days, you don’t have any idea what you ate.”
Although long-term consequences are rare, people with campylobacteriosis are at risk of complications such as septicemia (an infection of the bloodstream), sudden gall bladder inflammation (which involves sharp abdominal pain), meningitis, and Guillain Barré syndrome, an autoimmune disorder that affects the nervous system.
Campylobacter is far more common than the strain called E. coli O157:H7, but the latter gets the headlines because of the potential for severe side effects, especially in children.
Most symptoms of E. coli infection like diarrhea, vomiting, headache, and severe cramps, clear up on their own within five to 10 days. But some people who are infected go on to develop life-threatening symptoms, including kidney damage or failure, seizures, and stroke.
E. coli can be present in contaminated raw fruits and vegetables (including sprouts and chia seeds); unpasteurized milk, cheese, and apple cider; untreated water; and raw or undercooked meat, especially ground beef.
“There’s a reason we pasteurize milk,” Kurzac says. “There’s a reason hamburgers need to be cooked through, because there’s bacteria in the centre of that burger. With unpasteurized apple cider, the apples may have dropped on ground and fallen in animal feces.
“There seems to be a trend right now of undercooked burgers,” she adds. “Foodies say it’s a better way to eat it, because it will be juicy. When I hear that, I just cringe. Is it really worth it? E. coli is no joke. You don’t want to get it.”
Another illness that’s making the rounds this summer that’s not necessarily associated with food poisoning is the norovirus.
“I hear all the time people say, ‘I have a stomach bug,’ ” Kurzac says. “Norovirus is really prevalent in our community right now. You can get that from other people but also through food. It’s nasty.”
Noroviruses are a group of viruses that cause gastroenteritis, which is characterized by vomiting and diarrhea and which can come on suddenly. Most food-borne outbreaks of norovirus illness happen when food is contaminated by food handlers who have the virus, especially if they don’t practise proper hand-washing after using the bathroom. (Shellfish like oysters can be contaminated by sewage in water before they’re harvested.) Waterborne outbreaks can be caused by sewage contamination of drinking water or recreational water.
According to the Government of Canada, noroviruses can survive relatively high levels of chlorine and can persist on practically any surface, including door handles, sinks, railings, and glassware. On hard surfaces, they have been found to survive for weeks. On carpet and fabrics, noroviruses can survive for up to 12 days; in still water, they can live for months.
They’re highly contagious, and it only takes a minuscule amount to cause illness. Symptoms typically resolve quickly, within a day or two, without lasting complications.
However, as with any form of food poisoning, dehydration is a possible side effect. People need to ensure they’re drinking lots of water and replacing electrolytes, especially if they’re very young or old, immunocompromised, or pregnant.
Antibiotics are not advised to treat most bacterial forms of food poisoning, especially E. coli. And antibiotic resistance in general has become a health threat of its own. The unregulated use of antimicrobial agents in food-animal production has led to the emergence and spread of antibiotic resistance in Campylobacter, for instance, according to the Frontiers in Microbiology study.
The most effective way to avoid food poisoning is proper hand-washing, with emphasis on the word proper. Good hand-washing isn’t a swipe of the hands underneath the tap. Rather, it involves the kind of scrubbing that you see surgeons doing on TV.
“With good hand-washing, you vigorously rub your hands together for at least 20 seconds,” Kurzac says. “A lot of people don’t get the importance of that basic task to prevent a lot of these illnesses.”