The federal government is investigating 21 cases of E. coli in three provinces that are believed to be linked to the consumption of romaine lettuce.

The Public Health Agency of Canada says 13 individuals in Newfoundland and Labrador, five in New Brunswick and three in Quebec became sick with E. coli in November — 10 of whomhad to be hospitalized. No deaths have been reported.

Those who became ill are between five and 72 years old, and 71 per cent are female.

In Newfoundland and Labrador, the Department of Health and Community Services confirmed that all 13 cases happened in the Eastern Health region, and that all were diagnosed between Nov. 18 and 26.

The department said four of the 13 who were diagnosed were hospitalized.

No product recalls

Many of those diagnosed reported eating romaine lettuce before their illness started, and The Canadian Food Inspection Agency is working with public health officials to determine the source of the lettuce the individuals were exposed to.

At this time, there are no product recalls associated with the outbreak.

E. coli are bacteria that live naturally in the intestines of cattle, poultry and other animals. Most E. coli strains are harmless to humans, but some varieties cause illness.

E. coli are bacteria that live naturally in the intestines of cattle, poultry and other animals. Most E. coli strains are harmless to humans, but some varieties cause illness. (Flicker CC/National Institute of Allergy and Infectious Diseases (NIAID), NIH)

The risk to Canadians is low, according to the Public Health Agency of Canada, and Canadians are reminded to follow safe food handling practices for lettuce.

Most people with an E. coli infection will become ill for a few days and then recover fully. Some E. coli infections can be life threatening, though this is rare, the agency says.

The following is information from the Public Health Agency of Canada on how to protect against E. coli infection and how to identify symptoms.

What you should do to protect your health?

The following food safety tips for lettuce will help you reduce your risk of getting an E. coli infection.

Wash your hands thoroughly with warm water and soap for at least 20 seconds, before and after handling lettuce.

Discard outer leaves of fresh lettuce.

Wash your unpackaged lettuce under fresh, cool running water. There is no need to use anything other than water to wash lettuce. Washing it gently with water is as effective as using produce cleansers.

Keep rinsing your lettuce until all of the dirt has been washed away.

Don't soak lettuce in a sink full of water. It can become contaminated by bacteria in the sink.

Ready-to-eat lettuce products sold in sealed packages and labelled as washed, pre-washed or triple washed do not need to be washed again.

Use warm water and soap to thoroughly wash all utensils, countertops and cutting boards before and after handling lettuce to avoid cross-contamination.

Store lettuce in the refrigerator for up to seven days. Discard when leaves become wilted or brown.

Bagged, ready-to-eat, pre-washed lettuce products should also be refrigerated and used before the expiration date.

What are the symptoms?

People infected with E. coli can have a wide range of symptoms. Some do not get sick at all, though they can still spread the infection to others. Others may feel as though they have a bad case of upset stomach. In some cases, individuals become seriously ill and must be hospitalized.

The following symptoms can appear within one to 10 days after contact with the bacteria:

Nausea

Vomiting

Headache

Mild fever

Severe stomach cramps

Watery or bloody diarrhea

Most symptoms end within five to ten days. While most people recover completely on their own, some people may have a more serious illness that requires hospital care, or may lead to long-lasting health effects. In rare cases, some individuals may develop life-threatening symptoms, including stroke, kidney failure and seizures, which could result in death.

There is no real treatment for E. coli infections, other than monitoring the illness, providing comfort, and preventing dehydration through proper hydration and nutrition. People who develop complications may need further treatment, like dialysis for kidney failure. You should contact your health care provider if symptoms persist.