Canada's health minister says that a human swine influenza outbreak which may have killed up to 63 people in Mexico poses "no immediate threats to Canadians at this time."

However, Leona Aglukkaq says that federal officials, along with provincial health authorities, are closely monitoring the situation and are studying the virus and its effects.

"No cases of human swine influenza have been confirmed in Canada," she said at a press conference Friday afternoon in Ottawa.

At least 943 Mexicans have fallen ill with the illness, and Mexico City has shut down schools, libraries and other state-run facilities to contain the outbreak.

The same strain of swine flu has also sickened eight people in the southern U.S., officials confirmed Friday.

Meanwhile, the National Microbiology Laboratory in Winnipeg and the U.S. Centre for Disease Control confirmed that the illness is a new flu strain never seen before.

Canada's chief public health officer said Friday that authorities are probing a small number of flu-like cases in Canada to see if they match the Mexican illness.

"There's a handful that are being looked at across the country," he said, adding that the exact number of possible cases fluctuates daily. "So there isn't a specific number."

The news is worrisome as it could indicate the start of a flu pandemic. Epidemiologists have warned for decades that the next pandemic would likely be caused by an animal or bird flu that mutated so that it could be transmitted person-to-person.

On Friday afternoon, the CDC's acting director warned that officials must be vigilant in tracking the illness.

"Our concern has grown since yesterday, in light of what we've learned since then," said Dr. Richard Besser from Atlanta.

He added that U.S. officials confirmed an eighth case of swine influenza on Friday, this time it was in a child living in San Diego, Calif.

Though all of those with the illness in the U.S. have recovered, Besser said that the CDC is still learning about the illness.

While Besser stopped short of issuing a travel warning for California, Texas and Mexico, he said travellers should cover their mouth when coughing or sneezing, wash their hands regularly and notify a doctor if the following symptoms become apparent:

  • fever
  • cough
  • sore throat
  • eye pain
  • shortness of breath
  • muscle and joint pain
  • extreme fatigue

Officials are also asking people showing the symptoms to stay home from school or work.

Global response

The WHO says it is convening a committee of experts who will consider whether to raise the global pandemic alert level or launch efforts to try to contain the virus's spread.

"We can't say for sure that either a phase change or a rapid containment operation will happen. But both have been considered and are being considered," spokesman Gregory Hartl said from Geneva.

Hartl says the WHO is sending staff to Mexico to help in the investigations.

The world is currently at Phase 3 of the WHO's pandemic alert ladder, because of ongoing sporadic cases of human infection with the H5N1 avian flu virus. Phase 3 means there are occasional human cases with a novel flu virus. Phase 6 is a pandemic.

WHO would need the advice of an expert panel to move up to Phase 4 or beyond.

At Mexico's request, Canada's National Microbiology Laboratory in Winnipeg analyzed more than 50 samples from infected Mexican residents.

So far, the Canadian lab has identified 16 positive cases of swine flu. U.S. officials have identified seven cases from Mexican samples.

In Ontario, there are zero confirmed cases of swine flu, though officials are analyzing a "handful" of possible cases and awaiting the test results, said Dr. David Williams, the province's chief medical officer.

Williams added that "physicians are on a very high alert" but fortunately, Canadian travellers tend to visit coastal Mexican areas where the swine flu has yet to become a serious threat.

Mexico on alert

Schools and universities in Mexico City and the surrounding area closed on Friday. Mexican Health Minister Jose Angel Cordova is advising people with flu symptoms to stay home from work.

"We're dealing with a new flu virus that constitutes a respiratory epidemic that so far is controllable," Cordova said late Friday.

Across Mexico City, traffic was much lighter than usual and many people waiting to enter subway stations had their faces covered with surgical masks.

The virus is a never-before-seen mixture of viruses typical among pigs, birds and humans. The cases are unusual because it appears none of the patients had come in contact with pigs, suggesting that an animal virus is being transmitted from person to person.

The flu-like illness in Mexico has so far affected healthy young adults between the ages 25 and 44, mostly in south and central areas of the country, but not the tourist areas on the coast.

Canadian health officials have issued an advisory to health authorities to be on the lookout for travellers to Mexico who develop flu-like symptoms. Any Canadian who has returned from Mexico within the last two weeks and is suffering the symptoms should contact a physician.

As well, the CDC is advising doctors in the U.S. to consider the possibility of swine flu in patients who develop a fever and signs of respiratory illness and who have recently traveled to San Diego or Imperial County, Calif., or San Antonio.