TORONTO – Nearly three dozen wild ducks have tested positive for the H5 bird flu virus in Canada, officials reported Monday, but they said it was unlikely to be the strain blamed for more than 60 human deaths in Southeast Asia.

Dr. Jim Clark of the Canadian Food Inspection Agency said it would take at least a week to determine whether the flu found in 33 ducks from the provinces of Quebec and Manitoba was the deadly H5N1 strain that has ravaged Asian poultry farms.

But it was unlikely to be the same strain because none of the wild ducks tested was ill, he said at a news conference.

“That strain in Asia has caused high mortality in those birds; the birds that tested positive in Quebec and Manitoba are all healthy,” Clark said.

Clark said 4,800 samples had been collected from wild birds in seven Canadian provinces in a study begun before the recent spread of H5N1 from Asia to parts of Europe and Turkey.

He said it was not surprising to find a variant of the H5 virus in Canada. He said it can be present in at least 7 percent of wild birds in North America at any given time, but in less virulent forms than the H5N1 strain.

The spread of H5N1 across the Eurasian land mass has world health experts worried about the possibility of a human flu pandemic developing that could kill millions and cripple economies.