A British Columbia woman has been diagnosed with the first case of H7N9 avian flu in North America, according to health authorities.

The Metro Vancouver resident, who has not been identified, recently returned from China, where nearly 500 human infections with this strain of bird flu have occurred since 2013.

Health officials said the woman was not travelling in a high-risk area in China and did not show symptoms until Jan. 14, two days after she returned to Canada.

“She just said that it felt different than her usual influenza,” said Dr. Reka Gustafson, a medical health officer for Vancouver Coastal Health. “She really wasn’t able to tell us much more than that, but it was different enough to seek care.”

Her husband, who was travelling with her, was also suspected of contracting the virus. He has since recovered.

“He actually became more clinically ill, and then his wife within a day or so started developing systems and sought care from her family physician,” said Gustafson. The woman’s doctor swabbed her, which helped identify the virus.

Others who have had contact with the patient are being monitored for signs of avian flu, but none have fallen ill. The woman was not hospitalized and is now in self-isolation, officials said.

How she contracted the virus has not been confirmed. The married couple was on a guided tour for part of their trip to China, but travelled on their own the rest of the time.

Officials said most known human infections of H7N9 are believed to come from direct or indirect contact with live poultry that has been infected, for example, by visiting farms or live poultry markets.

There are currently no travel bans or restrictions related to H7N9, and officials are simply warning travelers to take precautions in high-risk areas.

Health experts say H7N9 poses a low risk to the public and is not easily transmittable. But it can be hard to tell which birds are infected, because the virus does not cause severe disease in poultry. Still, doctors in B.C. aren’t worried.

“Given the time since illness, and the fact that all contacts are currently well, it is extremely unlikely that we will see additional cases here in B.C.,” provincial health officer Dr. Bonnie Henry said in a news conference Monday.

Public Health Canada said there is no evidence to show that the disease can be transmitted person-to-person, and that so far in the investigation, “It seems that people are getting sick from close contact with infected birds.”

The H7N9 strain of avian flu can lead to symptoms of “severe respiratory illness, with about one-third resulting in death,” according to the Centers for Disease Control and Prevention.

Other symptoms of H7N9 include fever, cough, shortness of breath. An infection can also lead to pneumonia.

There is currently no vaccine for the virus. As of Oct. 2014, there were 453 lab-confirmed cases of human infection around the world, including 175 deaths, according to the World Health Organization.

The news comes about a month after an outbreak of H5N2 avian influenza at several Fraser Valley farms that led to tens of thousands of birds being euthanized.

With a report from CTV Vancouver's Maria Weisgarber