By: Pooja Sharma
The Public Health Agency of Canada are working alongside provincial public health partners, the Canadian Food Inspection Agency and Health Canada to investigate an Escherichia coli O157 outbreak that is commonly known as E. coli. The outbreak is ongoing and has been linked to romaine lettuce even though the cause of the contamination has not been confirmed yet. Based on investigations done by public health agencies in Canada, the outbreak has affected a total of five eastern provinces in Canada.
Canadian Health officials first announced the outbreak on December 11, 2017. The Public Health Agency reported the illnesses range from November and end by early December. However, there was 1 more case detected on 28th of December, which means that the outbreak has not ended yet. This additional case brings the total case count to 41 illnesses. Of these, 16 patients have been hospitalized, and 1 person has died as a result of this outbreak. Here is a total case count by province:
- Ontario (8)
- Quebec (13)
- New Brunswick (5)
- Nova Scotia (1)
- Newfoundland and Labrador (13)
Most of these patients reported eating romaine lettuce before they noticed first signs of illnesses. They had romaine lettuce at home or in prepared salads in restaurants, fast food chains, and grocery stores. People who got sick are between the ages of 4 and 85 years old. Most of the patients linked to the outbreak (73%) are female.
As the illnesses are ongoing, the contaminated lettuce is still on the market and in close proximity of people. The Canadian health officials have not found the source of contamination or any one particular brand of lettuce to name as the culprit. This means that the lettuce is likely being served in restaurants, grocery stores, buffets, and any other establishments that serve food. The product has a total shelf life of up to 5 weeks. There is still a risk of E. coli infections due to consumption of romaine lettuce. People who are more at risk of complications such as children, pregnant women, elderly, and those with impaired immune system should avoid (or limit) the consumption of romaine lettuce until all the sources of the outbreaks have been taken out of public reach.
There have been no recalls yet, but Sobey has temporarily halted sales of more than 300 of its Romaine Lettuce products that it sells under various brand names. The recall that took place across various locations around the country was issued as a precaution during the investigation. Sobeys Inc. has a total of 1500 stores in the 10 provinces and the products are sold under retail banners such as Safeway, IGA, Price Chopper, Thrifty foods, FreshCo, Foodland, etc.
What should you do to protect yourself?
To help prevent illnesses, if you do decide to eat romaine lettuce at this point of time, then there are steps you can take to prevent infection:
- Discard all the outer leaves of the lettuce. Wash the unpackaged lettuce under cold running water properly. Rinse the lettuce properly until all the dirt is removed.
- Do not soak the lettuce in a sink full of water. Your sink might be full of bacteria and the lettuce can get contaminated too.
- Store the lettuce in the fridge away from raw meat for up to 7 days.
- Ready-to-eat lettuce products that are sold in salads etc. and come in sealed packages and are labeled as washed, do not need to be washed once again.
- Properly wash all the utensils, countertops and cutting boards where you have put the lettuce to avoid any cross contamination.
People who reside in the most affected areas – Ontario, Quebec, Nova Scotia, New Brunswick, and Newfoundland and Labrador are advised to consume other kinds of lettuce to avoid any risk of infection.
What is E. coli O157?
Of the E. coli serotypes, E. coli O157 is the worst type of E. coli serotype that exists when it comes to infecting humans. It is a Shiga-toxin producing types of E. coli (STEC) and is known to cause bloody diarrhea and can lead to various complications such as HUS, kidney failure, and even death. It was discovered about 40 years ago and around 4% of the cattle are infected by it. The optimum temperature at which STEC can grow is 37℃, although STEC can grow in the temperatures ranging from 7℃-50℃. STEC can be destroyed by cooking at temperatures up to 70℃ or higher.
STEC produces Shiga toxin, which is one of the most potent toxins known to mankind. It inhibits protein synthesis in endothelial and other cells. The endothelial cells line the surface of blood vessels and this strain of E. coli is cytotoxigenic to the cells. Symptoms of STEC include: vomiting, diarrhea, and abdominal cramps. The incubation period is around 1-10 days. Around 10% of patients with STEC develop HUS, which directly affects kidneys and is predominant among children.
Fluid replacement and supportive care might be required to prevent death from dehydration. Most victims are able to recover from the infection without any treatment within 5-10 days. Antibiotics do not prove out to be that effective in case of E. coli O157:H7.
How does E. coli get into lettuce?
E. coli naturally live inside cattle, poultry, and other animals. Raw meats, raw fruits and vegetables are some of the most common sources of E. coli infection. The bacteria can infect the raw produce when the infected feces from animals comes in contact with the produce. The contamination can happen both during or after the harvest when the produce is in the process of storage, processing, and handling.
There has been a growing demand for block chain technology to be practiced in grocery chains, so as to let the distributors to share data digitally. It will help in tracking the source of the produce in a matter of few seconds. In a traditional supply system, it can take up to a week or two to trace the origins as the product can exchange hands multiple times during the supply process. Let’s hope that this technology soon becomes more prevalent in grocery chains in the coming days to help trace deadly outbreaks (like this one) sooner.