People living in Canada and the U.S. are being cautioned to stay away from romaine lettuce amid a new E. coli outbreak linked to the popular leafy vegetable.

Since the start of October, 18 people in Ontario and Quebec have gotten sick, with six being hospitalized. 32 people in 11 American states have also been affected, with 13 of those requiring a hospital stay.

Those affected are between 5 and 93 years of age with the majority of cases (56%) being female.

The Public Health Agency of Canada is working together with with provincial public health partners, the Canadian Food Inspection Agency, Health Canada, as well as the United States Centers for Disease Control and Prevention (U.S. CDC) and the United States Food and Drug Administration (U.S. FDA), to investigate the outbreak.

The E. coli strain identified appears similar to one linked to leafy greens last year.

Until they find the source to Canadians and Americans are being asked to avoid eating any romaine lettuce including in salad mixes .

Supermarkets and restaurants are also being encouraged to get rid of their romaine supplies as well.

People infected with E. coli can experience a wide range of symptoms, with some people never feeling sick at all. Others will feel like they have a really upset stomach.

Some of the symptoms that can appear within one to ten days after contact with the bacteria include: nausea, vomiting, headache, mild fever, severe stomach cramps and watery or bloody diarrhea.

There is no real treatment for E. coli infections. Most people recover within a week.