OTTAWA, Aug. 21 (Xinhua) -- More cases of listeriosis are expected in Canada amid a nationwide outbreak of the potentially dangerous bacterial infection, a senior health official said on Thursday.

    At a press conference in Toronto, David Williams, Ontario's Chief Medical Officer of Health, said he expects more cases to be reported in the coming weeks because listeriosis has an average incubation period of three weeks.

    He said that eight cases have been ruled out, with 17 cases confirmed, including 13 in Ontario, two in British Columbia and one each in Saskatchewan and Quebec. The person who died from the disease was an elderly woman from Hamilton, Ontario.

    Williams said the government first became aware of a problem with the bacteria on July 25 thanks to the province's post-SARS tracking system.

    But he said he could not confirm a direct link with the recent recall at the Maple Leaf Foods plant in Toronto.

    The closed processing plant has been identified as the "probable source" and Williams said they are waiting for confirmation by the Canadian Food Inspection Agency.

    The bacteria has been discovered at the Toronto plant but it has not been confirmed whether it is the same one that caused the outbreak. Maple Leaf has recalled about 500,000 kg of meat.

    Symptoms of listeriosis include nausea, vomiting, cramps and fever.