06/22/2011 06:49 EDT | Updated 08/22/2011 05:12 EDT

Canada E. Coli Outbreak Caused, Apparently, By Walnuts Is Over: Health Agency

THE CANADIAN PRESS -- OTTAWA - The Public Health Agency of Canada says an E. coli outbreak that caused 14 people to become sick appears to be over.

It says the last of the reported patients became ill on April 20, but the agency continues to monitor and investigate any new cases of E. coli that could be related to the outbreak.

And it says Canadians should still refrain from eating any of the walnuts distributed by Montreal-based Amira Enterprises that were listed in health hazard alerts in the spring.

But the agency says there's no indication that other raw, shelled walnuts pose a health risk and therefore it is no longer recommending that Canadians roast raw, shelled walnuts before eating them.

One patient in Quebec with an underlying medical condition died during the outbreak, which also affected people in Ontario and New Brunswick.

The agency says that based on the information available, raw, shelled walnuts are still the suspected source of the outbreak, although it was never confirmed by laboratory testing of walnuts.

"There are several possible explanations for this such as the difficulty in detecting low levels of contamination of E. coli 0157:H7 in dried foods," the agency said Wednesday in an email response to a query about whether the source had ever been determined.

"Although positive laboratory findings would confirm, negative findings do not disprove walnuts as the suspected source of the outbreak."