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B.C. teen diagnosed with avian flu remains in stable but critical condition

B.C.'s top doctor Bonnie Henry says probe into Canada's first recorded human case is closed for now
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B.C. public health officer

B.C. top doctor Bonnie Henry said the public health investigation into Canada's first human case of avian flu is closed for now, adding officials may never know how a B.C. teenager contracted the virus. 

During a media availability Tuesday, Nov. 26, Henry said the teen remains in "stable" but "critical" condition at B.C.'s Children Hospital, adding investigators have not been able to speak to the patient, only to family and friends. 

"Absolutely, if this person recovers, which we absolutely hope, and we have an opportunity to speak, we may be able to get more information," Henry said. "But that may not be possible," she said, noting that the teenager might not  remember details.

"So unless something changes, we won't be continuing. There's no further need, and we've been extensively looking for concentric circles of people who might have had contact with somebody, who might have had contact, or animals who have might had contact," Henry said.

She said earlier that the now-concluded investigation found no evidence of transmission from the teenager to other individuals and no evidence of other human cases.

Investigators tested 34 health care workers, 16 close family members and friends, and more than 25 animals who had exposure to the patient, including birds, rodents, reptiles, dogs and cats. Investigators also took 10 environmental samples from areas around the home and other places, including water sources, wastewater, and sediments, looking for signs of the virus. All of these tests came up negative. 

Henry added existing surveillance system will continue to look. 

The Public Health Agency of Canada confirmed Nov. 13 the teen was Canada's first human case of avian influenza (also known as bird flu) caused by influenza A(H5N1) virus. 

The teen — who did not have any underlying conditions — remains "very sick" and unable to breathe independently. The person's ability to recover and long-term consequences of the infection remain unknown.

"So there were some positive signs...over the last few days and we remain very hopeful," Henry said. "We are sending all of our thoughts to this young person and...family. Teenagers were very resilient and they can recover from these types of very severe infections, way more than older people. But there is a lot we don't know yet and the clinical care team doesn't know yet either." 

But more information is starting to emerge about the events that led to the teen's hospitalization and the possible origin of the virus. The teen first experienced a case of conjunctivitis in the eyes. The virus may have travelled from receptors there deeper into a lung said Henry, possibly through a mutation.

"Most of us with influenza don't get very severe, deep lung infections, but if the virus receptor binding area can change to recognize those receptors deeper in the lung. That increases the risk of having some more severe illness," she said.

While this theory is not "set in stone," scientists are looking at in detail, she said. 

Genomic testing has also revealed the virus affecting the teenager is not directly linked to the virus devastating the B.C. poultry industry. Rather it is associated with wild migratory birds, specifically cackling geese.

"So we don't know that it came directly from them, but it gives us the sense that it was closely related to wild birds, not the poultry farms."

Henry said the closest genetic match comes from a virus found in two cackling geese tested earlier in October.

"So that tell us as well that there might have been an intermediary, either another bird or an animal between the geese that were detected and this young person," Henry said. "But very importantly, it also tell us that this genotype was quite different from what is causing the devastating outbreaks in the poultry industry." 

She added that there is no evidence the teen had been near affected poultry farms. 

The teenager's virus is having a different effect than the virus found in human avian flu cases reported in Washington State, Henry added. Those cases are among 55 reported in the United States spread across seven states. Most were mild and mostly found among dairy workers. But California also recently reported a child case with exposure details unclear, Henry added. 

Overall, human cases of avian flu caused by the A(H5N1) virus are "rare" occurrences with 900 reported around the world. Nonetheless, she urged British Columbians to take precautions, as this year marks the sixth season of B.C. avian flu outbreaks. 

"Right now, our animal health colleagues tell us there is a lot of this virus in ponds and marsh areas," she said. "So what can we do? Critically, especially this time of the year, avoid sick animals and birds."

Henry also asked British Columbians to stay away from ducks, geese or poultry in petting zoos and keep dogs away from areas with bird droppings.

"If you are handling pets that have been outside, ensure that you wash your hands frequently," she said.

Henry also urged individuals to get their updated influenza vaccines, adding that protecting yourself against the human-influenza strain might offer some protection against the avian version, according to some research.

 

 

 



Wolf Depner

About the Author: Wolf Depner

I joined the national team with Black Press Media in 2023 from the Peninsula News Review, where I had reported on Vancouver Island's Saanich Peninsula since 2019.
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