B.C. teen with avian flu remains in critical care, no other cases identified

The teenager who is infected with the first human case of H5N1 avian influenza acquired in Canada remains in critical care at BC Children’s Hospital, officials said Tuesday.

Speaking at a news conference in Victoria, provincial health officer Dr. Bonnie Henry said the young person is stable, but still very sick and on a respirator.

“Our thoughts remain with them and their family, and we remain hopeful, as they have made some progress in the last few days, that they will recover from this very severe infection,” she said.

Identifying details about the patient, including exact age and gender, are not being released, but the teenager is from the Fraser Health Region, which stretches from Burnaby to Hope, and has no underlying conditions.

Over the past two weeks, public health has tested and monitored 34 health-care workers and 16 family and friends who had contact with the teenager for signs of H5N1, and all have come back negative.

“There is no evidence of transmission from this young person, and no evidence of any other cases right now in British Columbia,” Henry said.

In addition, more than 25 animals were tested and around 10 environmental samples collected during the investigation into the source of the teen’s infection, which also all came back negative.

As there are no further leads, Henry said the public health investigation has been closed for the time being, and it may never be known for certain where the individual was exposed.

However, genome sequencing revealed the specific virus to be closely related to one found in two infected wild geese found dead in the Fraser Valley in October, and is a different genotype to the viruses infecting poultry farms, or dairy cattle in the U.S.

“That tells us a lot. It helps us understand where the potential exposures might be, and it wasn't a direct match. So that tells us as well that there may have been an intermediary,” Henry explained.

She said scientists around the world are looking into the genome to investigate whether the virus is adapting to human infection.

In the U.S., there have been 55 confirmed human cases of H5N1 this year, mostly in dairy farmers who had mild infections. The virus was also detected in unpasteurized milk this week, according to officials, who add H5N1 has not been found in any cows or milk in Canada to date.

Migratory birds are natural carriers of avian flu, and the H5N1 strain has caused several outbreaks at poultry farms since 2022, leading to nearly seven million birds in B.C. being killed as farmers are required to do when a flock gets infected. There are currently 54 impacted facilities in B.C., according to the federal government.

“We are very aware of the pandemic potential of avian H5N1,” Henry said. “The more humans that are exposed to this virus and the more other animals, particularly other mammals…there's an increased risk that the virus might change and become more easily transmitted from person to person.”

She said she’s reassured, however, by the fact that many poultry farmers in B.C. have been exposed to the illness but have not been infected thus far. 

“I am very confident that there are no additional cases out there right now, but we still need to be careful, and we need to watch and think about, how do we prevent this from happening to anybody else,” Henry said.

Most of the poultry farms infected with avian flu are in the Fraser Valley. The infections have resulted in the culling of more than 1.3 million birds in B.C. since last month.

“Currently we have about 150 to 180 people deployed to respond to high path avian influenza in B.C. This has been our sixth wave of high path AI (avian influenza) in Canada,” said Troy Bourque, a veterinary program specialist and current lead of the western highly pathogenic avian influenza response team.

“When the migratory birds come north from Alaska into the Fraser Valley and reside there, that’s when the biggest risk is,” he explained.

“It’s devastating for a farmer when you get an infection on the farm,” said Shawn Hall, who speaks for the BC Poultry Association.

“We’re taking robust measures to protect farmers and farm workers (including) wearing personal protective equipment, masks and gloves, overalls, boots. Making sure that vehicles coming into the farms are carefully cleaned, monitoring for sick wildlife in and around the farms. And importantly, making sure that any birds acting in an odd way, showing any symptoms, that gets reported promptly,” Hall said.

Biosecurity on poultry farms is currently at the highest level, but officials continue to look for further ways to reduce the risk.

“I think the challenge is there’s such a high viral load in the wildlife population that it’s overwhelming those biosecurity protocols and practises that are in place and I think we need to have a hard look at biosecurity and see if there’s any way we can beef them up,” Bourque said.

Hall said despite the high number of birds destroyed, it’s still a minority of B.C.’s overall poultry farms and no shortages are expected.

“It’s not a food supply issue,” he said, adding that there is not food safety issue.

“Animals that are sick don’t enter our food system…and science is showing that cooking poultry effectively kills the virus anyway,” he said.

People can be exposed to H5N1 through handling sick birds or their droppings, and humans are infected, rarely, by inhaling the virus or rubbing it into their eyes.

Henry advised people to wash their hands, stay away from sick or dead animals, keep pets away from ponds and marshes, and not to handle ducks or poultry at petting zoos during the “high risk” migratory period.