As international health officials scramble to contain a deadly outbreak of Ebola in West Africa, Canadian border agents are now on alert for any signs of illness from travellers returning from abroad.

Prime Minister Stephen Harper on Wednesday said though the risk of infection is low, Canadian officials are monitoring the situation overseas.

“Obviously, this is a major epidemic in that part of the world and we are concerned about it,” Harper told reporters Wednesday.

The virus has now been reported in Guinea, Sierra Leone, Liberia and Nigeria, amid a massive outbreak that has claimed the lives of more than 700 people and infected thousands.

In response to the crisis, the Canadian government on Wednesday updated its travel warning to some of those countries, advising travellers to exercise extreme caution and seek medical at the first sign of illness.

There are no direct flights to Canada from the infected countries, but border agents are still on the lookout.

“What we’re looking for is fever -- anything when people look unwell is what our border agents are trained for,” said Dr. Gregory Taylor, deputy chief public health officer of Canada.

If someone is flagged, Taylor said, border agents call in a quarantine officer.

“The Quarantine Act allows us to detain a person and request a full medical assessment,” Taylor told CTV News.

In an effort to isolate those infected, Canada has sent two mobile testing units to West Africa.

“People who are very sick, they’re going to be so sick, that they won’t actually board a plane, they’re going to seek medical attention there,” said Dr. Neil Rau, an infectious disease expert.

Canada prepared for potential outbreak

One leading health expert says Canada is prepared to prevent the spread of the deadly disease in North America, should it pose a threat beyond Africa. There has never been a case of Ebola in Canada.

Dr. Keith Martin, executive director for the Consortium of Universities for Global Health, says while some 50 countries are now in the midst of developing networks aimed at responding to deadly bugs such as Ebola, Canada already has an “excellent” response system in place.

“But there’s a lot more to do, in a lot more countries,” Martin said in an interview on CTV’s News Channel Wednesday.

Martin said the response to the SARS crisis in 2003 prompted a more unified approach to global infectious disease control. SARS -- severe acute respiratory syndrome -- spread from China to various regions of the world, including Canada. Many health agencies were blindsided by the deadly disease, which killed dozens of people and prompted travel advisories from the World Health Organization.

“We lost a lot of money globally on SARS by not being prepared,” Martin said.

Prior to SARS, Martin said, public health agencies kept information private, and there was no proper mechanism for detecting “bad bugs” like Ebola. He said public health agencies, and organizations like the Centres for Disease Control, now take a more unified approach.

“They’re starting to collaborate to develop a surveillance mechanism where we can identify bad bugs when they happen, and develop the appropriate response and the international warning mechanism that’s necessary to prevent such a bug from actually expanding and killing a lot more people,” Martin said.

As a precautionary response to the Ebola threat in Africa, some airlines are cancelling flights to and from areas where there is a higher concentration of Ebola cases. But Martin said the deadly bug is actually fairly difficult to contract, since it requires contact with bodily fluids infected with the bug.

“Unless you’re coming in close contact with the body secretions of (infected) animals or somebody who has died or is infected with Ebola, you’re not going to get Ebola,” Martin said.

With files from CTV’s Richard Madan