The Public Health Agency of Canada says a deadly E. coli outbreak linked to romaine lettuce appears to be over.
The agency says as of Wednesday there have been 42 cases of E. coli illness reported in five provinces -- eight in Ontario, 15 in Quebec, five in New Brunswick, one in Nova Scotia and 13 in Newfoundland and Labrador. Seventeen people were hospitalized and one person died.
It says there have been no reports on the onset of illness since Dec. 12.
Based on the investigation findings to date, the agency says exposure to romaine lettuce has been identified as the source of the outbreak, but the cause of contamination has not been determined.
The Canadian Food Inspection Agency says it has completed its food safety investigation and all samples tested were negative for E. coli.
The Public Health Agency is still advising Canadians to always follow safe food handling tips for preparing lettuce, but says it's no longer advising consumers in the affected provinces to consider types of lettuce other than romaine.
In the United States, the Centers for Disease Control, several states, and the U.S. Food and Drug Administration continue to investigate the source of the outbreak, which caused illnesses 15 states.
Some Canadian restaurant chains stopped serving dishes with romaine lettuce during the outbreak.
Cara Operations Ltd. instructed its various chains with locations in those five provinces and P.E.I. to stop serving dishes with romaine lettuce on Dec. 27, spokeswoman Carmen Bain said last week.
The company operates Swiss Chalet, Milestones Grill + Bar, Montana's Cookhouse, Kelsey's, East Side Mario's and other chains.
Boston Pizza International Inc. also temporarily suspended the sale of all types of romaine lettuce at the pizza joint's locations in Ontario, Quebec and Atlantic Canada as of Dec. 26.
E. coli are bacteria that live naturally in the intestines of cattle, poultry and other animals.
A common source of E. coli illness is raw fruits and vegetables that have come in contact with feces from infected animals. Leafy greens, such as lettuce, can become contaminated in the field by soil, contaminated water, animals or improperly composted manure.
People infected with E. coli can have a wide range of symptoms, including nausea, vomiting, headache, mild fever and severe stomach cramps, which can appear within one to 10 days after contact with the bacteria.
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, people can become seriously ill and must be hospitalized.