Geese occupying a pond/via Derrick A. Mayoleth
A note of caution for people in BC to avoid contact with ponds and other areas where wild geese and other migratory birds may gather.
“We also want to make sure we keep pets away from birds, but also from ponds and areas that they might want to go into right now, because we know that ponds that have ducks and geese in them right now can have virus in the water that lasts for some time,” said Dr. Bonnie Henry, BC’s Chief Medical Health Officer, during a Tuesday update on BC and Canada’s first-known human infection of H5N1.
Henry says testing done on the virus which infected the unidentified teenager early this month indicates it is closely tied to a strain of H5N1 which has been found specifically among infected wild geese, but with a more potentially frightening adaptation.
“Having scientists from around the world being able to look at this genome, there was identified some mutations in the virus that may indicate [the ability of] adapting to humans,” said Henry.
However, she says testing of people who had direct contact with the victim before and after their symptoms presented show no infections among them — including over 30 medical personnel who treated the teenager before bird flu was confirmed.
Henry says while bird flu doesn’t appear to be making a jump from human to human, she says officials are aware of the potential for that to change.
“It’s an influenza virus of birds that has been spreading very rapidly in birds,” noted Henry. “But more humans being exposed to this, the virus can change and adapt to be more able to infect people or pass from person to person.”
Chief Medical Health Officer of BC, Doctor Bonnie Henry, providing an update on a human bird flu infection, Nov. 26, 2024/via Government of BC
Source of infection remains unclear
While scientists have been able to get a better idea of what strain of the H5N1 virus infected the teenager, how they contracted it does — and could remain — a mystery.
Henry says an extensive investigation has been unable to back-trace the source.
“Multiple tests were done in many different species of animals, including one potential source of the exposure to this young person, which was a pet dog which was sick at the time of the onset of illness of this child,” noted Henry, who says the animal tested negative for the virus. “This dog was thoroughly investigated with every test possible. All of the additional testing that was done, including samples from many different parts of this dog, all of them have been negative for H5 influenza.”
However, Henry does concede their ability to detect a bird flu infection in a dog is somewhat limited.
“We consulted with colleagues across Canada and the US,” said Henry. “There have been only two known cases of canine H5 in the world, so there is a lot we don’t yet know about how this virus might present in a dog.”
Henry says the genetic testing done on the virus has determined its not related to an outbreak in dairy cows, which have led to over 50 human infections among farm workers in the United States.
Instead, she says the genome of the virus is closely related to that of an H5 infection confirmed in a pair of wild geese discovered in the Fraser Valley in October, which are believed to have contributed to the outbreak among at least 54 poultry farms in the Fraser Valley so far this migratory season.
However, Henry says this is as far as they’ve been able to get, noting the victim didn’t have any direct contact with the infected farms.
“That tells us as well that there may have been an intermediary, either another bird or an animal between the geese that were detected, and this young person.”
Henry says the public health portion of their investigation has concluded for the time being, and warns they may never be able to find the source.
“The young person who is infected is still in critical care,” noted Henry. “So we are not able to talk to them directly about where the exposure might have happened.”
The teen, who did not have any underlying medical conditions, was admitted to BC Children’s Hospital on November 8th after their symptoms became acute respiratory distress.
Bird flu was confirmed as the source of the illness the following day.
The victim originally underwent emergency room treatment for a fever and cough, as well as conjunctivitis — commonly known as pink-eye — on November 2nd.
