TORONTO/VANCOUVER (Reuters) - Canada reported its first confirmed cases of swine flu on Sunday at opposite ends of the country, including two in the western province of British Columbia and four in the Atlantic province of Nova Scotia.
Health officials in both provinces said all the cases involved only mild illness, and the people either contracted the virus because they had recently traveled to Mexico or had contact with someone who had been there.
Even so, Canadian health officials urged people to take precautions such as frequent hand washing and said they would take whatever actions are necessary to protect the public.
"The swine flu symptoms seen in Canada have thankfully been relatively mild and the patients are recovering," Canadian Health Minister Leona Aglukkaq told a media briefing.
"As we continue to ramp up our surveillance efforts, these cases are likely not the last we'll see in Canada."
Ontario, Canada's most populous province, and Alberta both said they had no confirmed cases.
Millions of Mexicans stayed indoors to avoid a virus that has already killed up to 81 people there and new infections in the United States fanned fears of a global swine flu pandemic.
Mexico is a popular winter vacation spot for Canadians, but there were signs this was being hurt. Air Canada said it was waiving the fees charged to people who want to delay trips to Mexico before the end of April.
Canadian border staff were are trained to monitor travelers returning from Mexico and elsewhere for signs of illness.
Nova Scotia health officials said the four cases there were at a school where students had recently traveled to Mexico. The cases were confirmed with tests at a national lab in Winnipeg.
"These cases are mild. No one in Nova Scotia has been hospitalized because of the illness. All those who have been affected are recovering," Dr Robert Strang, chief public health officer for Nova Scotia, told a televised news conference.
"It was acquired in Mexico, brought home and spread."
The two cases in British Columbia were not related to each other, but both involved young men from the Vancouver area who had recently been traveling, according to the British Columbia Center for Disease Control.
Health officials said because both cases were both mild, the only reason they discovered it was swine flu was because the doctors had asked to get extra testing for patients with flu-like symptoms who had recently been to Mexico.
Strang said the Nova Scotia cases developed in a cluster at a private school near Windsor among a group of students aged 12 to 18. A group from the school had traveled to Mexico in early April.
Nova Scotia health authorities said they did not yet know how many cases there had been in total, as many students who have since recovered reported only mild symptoms. But they said it appeared there could have been 20 to 25 cases.
Canadian health officials say it is still unclear why the cases reported here and in the United States have not produced the severe respiratory illnesses reported in Mexico.
The swine flu cases have stirred up memories for many Canadians of the 2003 outbreak of severe acute respiratory syndrome, or SARS. That outbreak killed 44 people in Canada, the highest death toll outside of Asia.