'Pandemic potential': Risk of mutation of avian flu, Canadian doctor warns

H5N1 or avian flu is decimating wildlife around the world and is now spreading among cattle in the United States, sparking concerns about "pandemic potential" for humans. Now a health expert is urging Canada to scale up surveillance north of the border.

"The risk grows the more mammals are infected," Dr. Isaac Bogoch, a Toronto-based infectious disease specialist, told CTV News Channel on Sunday. "The more mammals that get infected, the more opportunities there are for this virus to mutate."

• Top health headlines, all in one place

Bogoch is urging authorities to "actively search" for the virus and implement broad-based surveillance as the risk grows in Canada because of the scale of the outbreaks south of the border.

“You know, if you don't look you'll never find it," Bogoch told CTV News Channel host Renee Rodgers. " Cast a broad net."

Why should we be concerned?

Matthew Miller, from McMaster's Immunology Research Centre in Hamilton, agrees with the infectious disease specialist and says bird flu's transition to spreading readily in mammals has happened quite suddenly.

He told CTV News Toronto although it's not "inevitable" that the disease will become more transmissible among humans, "the risk, I would say, is profound."

• 5 Things to Know newsletter: Sign up to start your day with the biggest stories

Bogoch also agrees, saying the "key goal" for health officials is to quickly identify where the cases are and rapidly quell outbreaks to prevent mammalian transmission.

"Obviously we wouldn't want it to be more transmissible," Bogoch said.

Public Health Agency of Canada (PHAC) says the National Microbiology Laboratory in Winnipeg is ready to rapidly test and detect human cases of bird flu to monitor any transmission and spread of the virus to humans.

"PHAC has established a surveillance system for emerging respiratory diseases which, in collaboration with jurisdictions, allows for the detection and monitoring of individuals occupationally exposed," Anna Maddison, spokesperson for the PHAC wrote in an email to CTVNews.ca.

• Looking for information on what Canada's doing? Read more here

Although the risk of H5N1 infecting people in Canada is low, PHAC is warning Canadians to avoid contact with any live or dead wildlife.

Those who cannot, according to PHAC, like farm workers, veterinarians, hunters and wildlife workers, should wear proper personal protective equipment and practice good hand hygiene.

U.S. struggling to contain large outbreaks

However, as calls for Canada to proactively prepare grow, outbreaks are spreading across the U.S. – leading authorities scrambling to contain the spread in several states.

"They realized it was far more widespread than initially thought." Bogoch said, "Now they're scrambling to get this under control.

• The information you need to know, sent directly to you: Download the CTV News App

His advice? Cast a "wide net" and test as much as possible.

"So one of the things that we're seeing is, is checking the milk supply," Bogoch explained. "You want to find zero signal."

Samples of milk collected from sick cattle from Kansas to Texas have tested positive for avian flu, but the U.S. Department of Agriculture says the nation's milk supply remains safe.

"If you do see a signal that means that there obviously are some impacted herds," Bogoch said.

Another infection mitigation strategy, according to Bogoch is one that became popular during the COVID-19 pandemic -- wastewater surveillance.

"It's pretty low cost, very high yield and it's actionable," Bogoch said. "You can identify [spread] before an outbreak occurs."

Miller is also recommending "systematic surveillance" of cattle in Canada, saying it's "warranted at this time" given the risk in the U.S.

"We don't have all the answers"

The detection in milk and a dairy products show how wide the virus can reach – and experts warn that it can spread quickly after outbreaks hit migratory bird species.

"Then scavenging mammals come into contact with the dead birds," Bogoch explained. "They eat the dead birds… and they get infected."

Even though Canada has yet to have "active cases" in Canada, Bogoch warned that now is the time for us to prepare, which includes more testing of dairy products at the retail level.

"The pasteurization process is fantastic and, and inactivates, the virus." Bogoch said. "We don't sell raw milk here."

• Sign up for breaking news alerts from CTV News, right at your fingertips

He also said that the latest data from the United States also shows that their "pasteurization process" remains safe, however the fact "viral fragments and inactive virus" are being found in commercially available milk is "unsettling."

"It just shows that the scale of this outbreak, in this case, it's in dairy cows and of course other mammals."

The fact that the outbreaks are so much larger than initially anticipated, according to Bogoch, should show authorities that the virus monitored for more transmissible mutations because infection carries severe risks to humans and other mammals.

"We have to be humble and appreciate that we don't have all the answers," Bogoch warned, "We have to take this virus seriously."

With files from CTV News' Christl Dabu and CTV News Toronto's Pauline Chan