Public health officials in North Bay say there are 146 suspected E. coli cases in the city, 24 of which have been confirmed by laboratories.

Included in that total are cases being investigated by six other Ontario health units, including Toronto.

"At this time we believe the outbreak is localized to Harvey's Restaurant on Algonquin Avenue in North Bay," the North Bay Parry Sound Health Unit said Saturday in a news release.

That restaurant is currently closed.

As of Friday, 131 cases had been reported.

"In the emergency department they noticed it was slowing down, and even slower today," said medical officer of health Dr. Catherine Whiting on Saturday. "I think we're on the other side of the epidemic curve."

The specific bacteria involved in this outbreak is E. coli O157:H7.

People get sick from it by eating food contaminated with the bacterium. They don't start to show symptoms for 24 hours to 10 days after becoming exposed.

"Once the person has symptoms, E. coli O157:H7 can be passed from person to person, for example, by hand-to-mouth contact through improper handwashing after using the toilet," the news release said.

"After symptoms have resolved, an adult can still spread the bacteria for one week or less and children for up to three weeks.  Good hand washing is the best way to protect yourself, your family and others."

Whiting said up to 10 per cent of the cases may be secondary, meaning someone became ill after coming in contact with a person who had been sickened by the initial source.

E. coli symptoms include:

  • Diarrhea, which may be bloody
  • Stomach cramps
  • Possibly vomiting
  • A fever

No deaths have been reported in the North Bay outbreak, but in general, the elderly and the very young are most at risk. The age range of those affected in North Bay ranges from one to 90. Nineteen people have been hospitalized, with three still recovering.

The North Bay outbreak is considered to be the second-largest since Walkerton.

In May 2000, an E. coli outbreak in Walkerton, Ont. linked to tainted water left seven people dead and another 2,500 sickened -- making it one of the worst public health disasters in Canadian history.

"Walkerton was a municipal water source, a drinking water source, to which many more people were exposed, and over time," Whiting said. "We have learned a lot from that outbreak."

A recent study of Walkerton survivors found that people sickened by E. coli are at significantly higher risk of permanent kidney disease.

With files from The Canadian Press