B.C. investigating 1st presumptive human case of H5N1 avian flu acquired in Canada

British Columbia health officials are investigating what's believed to be the first human case of H5N1 avian influenza caught in Canada after a teenager tested presumptively positive for the disease, the Ministry of Health announced Saturday.

The teenager, who the ministry says is from the Fraser Health region, is currently receiving care at B.C. Children's Hospital while officials work to confirm the diagnosis and trace potential sources of exposure.

According to the statement, avian influenza — also known as bird flu — is a virus that primarily affects birds but can occasionally spread to humans through contact with infected animals or contaminated environments.

B.C.'s provincial health officer, Dr. Bonnie Henry, says the case marks the first time H5 avian influenza has been caught by a person in Canada, as far as they know, although there have been isolated cases reported in the U.S. and other countries. 

"Our thoughts are with this young person and their family during this difficult time," she said. 

 In 2004, two poultry farm workers in the Fraser Valley fell ill with the H7N3 strain of avian flu. According to Public Health Canada, H7N3 typically presents with mild symptoms while H5N1 typically presents as severe.

Henry said a thorough investigation is underway to understand how the virus may have been contracted.

The ministry noted that public health officials are tracking contacts of the patient to monitor for symptoms and to provide guidance on testing and prevention measures.

Currently, no other human cases have been identified in connection with this incident.

Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital, said the virus is of particular concern because it has the potential to cause "significant clinical harm " in humans.  

"This has been a virus that's been on the radar to cause epidemics or potential pandemics," he told CBC News.

WATCH | B.C. teen tests positive for avian flu — a first in Canada: 

Teen has Canada’s 1st presumptive human H5N1 avian flu case

2 months ago

Duration 2:42

A B.C. teen is being treated in hospital for a presumptive case of the H5N1 strain of avian flu, the first known case contracted in Canada. Officials are working to find the source of exposure and follow up with any contacts. Correction: A previous caption for this video incorrectly described the first domestically acquired case of Avian Influenza. It is in fact the first case of someone acquiring the H5N1 strain of the virus in Canada. There were cases of the H7N3 strain acquired in B.C.'s Fraser Valley in 2004.

While human infections with avian influenza are rare, Health Canada says symptoms can range from mild to severe, potentially leading to pneumonia, organ failure and even death.

Since 1997, over 900 human cases have been reported globally, primarily in Asia and Africa, with about half of them resulting in death, according to Health Canada. However, the government cautions this fatality rate may be overestimated, as mild infections can often go undetected and underreported.

Another part of what makes the virus concerning, Bogoch said, is its ability to "reassort" — or swap genes — to make it more readily transmissible. 

According to the Toronto-based physician, avian flu outbreaks in the U.S. have already led to at least 44 human cases, though he said this may be a "gross underestimate."

"We know that political borders don't stop the spread of infectious diseases and, of course, this can happen in Canada and elsewhere around the world," he added.

WATCH | Human infection linked to U.S. dairy cow H5N1 outbreak: 

Human bird flu case linked to U.S. dairy cattle outbreaks

9 months ago

Duration 2:32

A person in Texas who had close contact with infected dairy cattle has been diagnosed with bird flu. It's the country's second known human case after the virus was discovered circulating among dairy cows across at least four U.S. states for the first time.

According to the federal government, there has only been one human case of A(H5N1) ever reported in Canada. A Canadian resident died of avian influenza A(H5N1) in early 2014 after returning from a trip to China, where they were likely infected.

Since early October, the H5N1 virus has been detected in animals at numerous sites in B.C., including 22 poultry farms and in a variety of wild birds and small mammals such as foxes and skunks.

Earlier this week, Vancouver Island's health authority warned residents about a possible exposure to avian flu at a petting farm in Campbell River.

The Canadian Food Inspection Agency says that, as of Nov. 10, there were 23 sites — most of which are commercial poultry operations — actively dealing with avian flu infections in B.C.

Over 6.4 million birds in the province are estimated to have been impacted.

Avian flu outbreaks are more likely to occur during fall, when migrating wild birds can pass it on to poultry farms or backyard flocks, according to Shawn Hall, a spokesperson for the B.C. Poultry Association.

Hall said farmers are urged to move their flocks indoors and adopt safety precautions during this high-risk period.

"Guests are only allowed on the farm when it's essential and with an appointment," he told CBC News. "[Farmers] wear [personal protective equipment] to help prevent the spread."

In light of the confirmed cases among animals in B.C., officials are recommending that residents avoid direct contact with sick or dead animals, keep pets away from affected wildlife and report any dead or ill birds or mammals to provincial authorities.