WINNIPEG - A resurgence of swine flu anticipated this fall could test new provincial powers that include being able to place sick people under quarantine in their homes and shut down schools.

Many provinces have passed updated public health acts in recent years to give them the right to do whatever a medical health officer feels is necessary to curb the spread of a communicable disease.

None of the powers has been used so far in the new H1N1 outbreak, but that could change if the country is hit with another wave of the

flu, says Manitoba's top health official.

"We haven't had to quarantine or limit restrictions in the community based on our current situation," said Dr. Bunmi Fatoye, the province's acting chief public health officer.

"Would we have to do that in the future? We may. It all depends on how the disease evolves in the fall. That would determine what measures to take, if we think that method of quarantine would limit the spread of the disease."

Manitoba's revamped public health act came into effect in April, just as the H1N1 virus was emerging. When the bill to amend the act was first introduced in 2005, the chief public health officer said it was needed to stop disease from spreading "particularly in the early stages of a pandemic."

One way of curbing the spread of a deadly, uncontrollable disease is to prevent large numbers of people from gathering, Fatoye said.

"Schools might be closed down. That's one way of limiting it," she said. "If you don't have to go out, then don't go out. But those are usually very, very severe measures. I'm not sure if we're going to get there, but we can't say until we see how the disease will play out in the fall."

About five dozen people in Canada have died of swine flu and thousands more have fallen ill. Experts are concerned those numbers will rise when temperatures start to cool and the virus is transmitted more efficiently.

Arlene King, Ontario's chief medical health officer, said Canada could be grappling with four different types of flu come fall. Up until now, it hasn't been necessary to rely on the province's public health legislation which was strengthened in 2007.

But if King believes people's health is at risk, she has the power to "investigate the situation and take such action as he or she considers appropriate to prevent, eliminate or decrease the risk." That could include closing schools, isolating the ill and forcing others to undergo medical exams.

But just because she has new wide-ranging powers, that doesn't mean she would jump at the chance to use them, she said.

"We have to be very cautious in exercising these powers."

Maureen Baikie, deputy chief medical health officer for Nova Scotia, said the province updated its public health act after SARS hit Canada in 2003. The top health official can now quarantine the ill, interview anyone who has been in contact with a sick person and do anything else that could help prevent the spread of a virus.

"It's significant authority that we have that is there if we need it," she said. "But there is a difference between having the authority and actually using it."

Most people who are seriously ill want to do the right thing and follow the advice of public health officials, she said. People aren't ordered into quarantine without first being given the chance to isolate themselves, she pointed out.

"We always try and balance individual rights versus the public good," said Baikie, who added that someone who is ordered into quarantine and is unable to work may also be compensated for their loss of income.

"They're doing something for the public good. We need to help them to do that."

British Columbia brought in a new public health act last year which was described as giving health officials "stronger powers to protect the public against communicable diseases such as pandemic influenza."

Under the new act, the province can order vaccinations or examinations and quarantine people. Health officials can also enforce the act using peace officers, warrants and even court orders.

Brian Emerson, medical consultant with the British Columbia government, said officials now have more authority to respond to a health emergency. But he warned that not all the weapons in the public health act's arsenal are effective against swine flu.

"Because of the rapid spread and easy way it gets transmitted person to person, doing something like large-scale quarantine and isolation just isn't a measure that is generally used for influenza," he said.

"Because such large numbers of people get affected so quickly, chasing down individual cases of influenza and instituting quarantine and isolation measures ... it has no effect on the spread of disease."