Public Health Notice - Outbreak of Listeria infections under investigation

Why you should take note?
The Public Health Agency of Canada is collaborating with federal and provincial public health partners to investigate an outbreak of Listeria monocytogenes infections in five provinces. To date, the source of this outbreak has not been confirmed. However prepackaged leafy greens, salad blends, and salad kits are food items being investigated. This notice will be updated as new information becomes available. 

At this time, the risk to Canadians is low, but given that Listeria can cause severe illness to some high-risk groups, Canadians are being asked to review and follow proper safe food handling practices in an effort to prevent illnesses.

Listeria is a type of bacteria that can be found in food, soil, plants, sewage and other places in nature. Eating food with Listeria on it can cause a serious disease, called listeriosis, in high-risk groups. People can get listeriosis by eating meat, fish, dairy products, plants or vegetables contaminated with Listeria.

Also read, Public Health Notice Update - Outbreak of Salmonella infections under investigation.

Ongoing Investigation
Currently, there are seven (7) cases of Listeria monocytogenes in five provinces related to this outbreak: Ontario (3), Quebec (1), New Brunswick (1), Prince Edward Island (1), and Newfoundland and Labrador (1). Individuals became sick between September 2015 and early January 2016.
The majority of cases (71%) are female, with an average age of 81 years. All cases have been hospitalized, and one person has died, however it has not been determined if Listeria contributed to the cause of death.

Who is most at risk?
Some people face a higher risk of becoming sick with Listeria than others. Those who are at highest risk of serious illness include pregnant women and their unborn/newborn children, adults 65 and over, and people with weakened immune systems. High-risk individuals should follow safe food handling practices and avoid high risk food items such as:

• uncooked meat and vegetables including pre-packaged leafy greens;
• unpasteurized (raw) milk and cheeses and other food made from unpasteurized milk;
• ready-to-eat meats such as hot dogs, pâté and deli meats; and
• refrigerated smoked seafood and fish.

What you should do to protect your health?
Following safe food handling practices is the key to preventing Listeria and the spread of foodborne illnesses. Foods that are contaminated with Listeria may look, smell and taste normal. Unlike most bacteria, Listeria can survive and sometimes grow on foods being stored in the refrigerator. Listeria can be killed by cooking food properly, and illnesses can be avoided by following these food safety tips:

• Thoroughly clean fruits and vegetables before you eat them. Wash your leafy greens under fresh, cool running water.
• Don't soak leafy greens in a sink full of water. They can become contaminated by bacteria in the sink.
• Thoroughly clean and sanitize all surfaces used for food preparation after handling foods in the kitchen, especially raw foods such as meat and fish.
• Read and follow all package labels and instructions on food preparation and storage.
• Cook foods thoroughly, using a clean thermometer to measure the temperature.
• To avoid cross-contamination, clean all knives, cutting boards and utensils used with for raw food before using them again.
• Refrigerate or freeze prepared food and leftovers within two hours.
• Defrost food in the refrigerator, in cold water or in the microwave, but never at room temperature.
• Keep leftovers for a maximum of four days, but preferably for only two to three days. Reheat leftovers to an internal temperature of 74ºC (165ºF) before eating them.
• Check the temperature in your refrigerator using a thermometer to make sure it is at 4ºC (40ºF) or below. The higher the temperature in your refrigerator, the greater the risk that Listeria may grow in foods. The risk of getting sick increases as the number of bacteria in food rises.
• Wash and disinfect your refrigerator frequently. The more often it is cleaned, the less chance there will be for Listeria to be transferred from contaminated food and surfaces to non-contaminated foods.

Symptoms
Many people are exposed to Listeria, but only a few will actually develop listeriosis. Mild symptoms may include:

• fever
• muscle aches
• nausea
• diarrhea

Severe symptoms may include:

• headache
• poor coordination
• seizures
• neck stiffness

In the milder form of the disease, symptoms can start the following day after consuming a product with Listeria. For the more serious form of the disease, the incubation period is generally much longer; on average about 21 days, but can be up to 70 days after exposure.

Listeriosis can be treated with antibiotics, but early diagnosis is key, especially for people at high-risk, such as pregnant women, older adults and people with weakened immune systems.

What the Public Health Agency of Canada is doing
The Government of Canada is committed to food safety. The Public Health Agency of Canada is leading the human health investigation of this outbreak and is in regular contact with its federal and provincial partners to monitor and take collaborative steps to address the outbreak.
Health Canada provides food-related health risk assessments to determine if the presence of a certain substance or microorganism poses a health risk to consumers.
The Canadian Food Inspection Agency (CFIA) conducts food safety investigations into the possible food source of an outbreak.

The Government of Canada will continue to update Canadians if new information related to this investigation becomes available.

Additional information

• Listeriosis and Listeria Fact Sheet
• Leafy Greens Fact Sheet

SOURCE Public Health Agency of Canada