A British Columbia doctor who treated a 13-year-old avian flu patient says the case has made him concerned about the potential for more human H5N1 infections.
While the patient was recently discharged from hospital with her case deemed rare, the two-month ordeal is being examined to better understand the path of avian flu from wild birds and poultry to humans, who get very sick.
Dr. David Goldfarb, a medical microbiologist and pediatric infectious disease physician at B.C. Children’s Hospital first saw the young patient on Nov. 8.
She was in respiratory distress, but there was no “clear flag” that suggested she was infected with H5N1. Goldfarb sent diagnostic tests to the hospital lab to determine the type of influenza that had sickened the teen. They all came back negative.
Occasionally, he said this happens if the sample is weak with a very small amount of the virus in it.
But it wasn’t a weak sample. It was actually reasonably strong, he said.
As Goldfarb took a closer look at the case, he started to notice symptoms associated with recent cases of avian flu, such as pink eye and wanted to test his theory as soon as possible.
“I called my colleague at the B.C. Centre for Disease Control and arranged for urgent testing for the H5N1 test, which is for the avian flu strain. That was done that same day, and we had that result by the evening of the admission to our hospital,” Goldfarb said.
The result was positive and was the first human case of H5N1 in Canada.
The teen’s medical team expanded to dozens of specialists while public health officials in Canada investigated how she got infected, the source of which remains undetermined. A lead expert on avian flu at the U.S. Centers for Disease Control and Prevention (CDC) was consulted on next steps.
She started an antiviral the day of her diagnosis. The team initiated a combination therapy that added two other antivirals, sourcing one from the U.S., to her treatment.
In respiratory distress, the teen patient was intubated and placed on life support on Nov. 9. Daily plasma exchanges started Nov. 14.
“This child needed a lot of support, basically the maximum amount of respiratory support that we’re able to provide in a modern ICU,” Goldfarb said.
This multidisciplinary approach went on for weeks until the patient’s respiratory condition began to improve. She was taken off of supplementary oxygen on Nov. 22 and extubated the following week.
A hospitalized 13-year-old B.C. girl believed to be the first person to acquire H5N1 avian flu in Canada is now out of intensive care and breathing on her own. The source of her infection remains unknown, but she is no longer infectious.
On Jan. 7, she was discharged from hospital. Her family released a statement asking for privacy as they healed from the traumatic experience.
Goldfarb said he couldn’t share more about the patient’s current condition or what her medical care would look like moving forward, but he said that the patient had recovered to the point that she was able to go home.
Genetic mutation
The B.C. Centre for Disease Control (BCCDC) is comparing the genetic features of her avian flu strain with that of a Louisiana patient who died last week. The U.S. patient, who was over the age of 65 and had underlying health conditions, shared one of the three genetic mutations identified in the Canadian teen’s strain, which infectious disease experts have said could make it easier for the virus to spread from person to person.
Goldfarb said the shared mutation is associated with binding to human cells better. A virus can’t live on its own, he explained, “It’s basically an inanimate object. But once it attaches to a host is when it becomes animated and then begins its life cycle … if a virus is able to bind better, then that means it can then potentially transmit to others.”
With the B.C. patient, there was no evidence of human-to-human transmission, which Goldfarb said means the mutation was a dead end in this case.
Still, he said, “It was worrisome, because theoretically, if this virus is able to do this and has more opportunities to adapt to humans, there may be a situation where it does become more adept at human-to-human transmission.”
CBC News reached out to the BCCDC for more details about what researchers are looking at but did not receive a response in time for publication.
In North America, he said we’ve been relatively sheltered from the spread of avian flu until this point. Historically the risk of infection was highest for those travelling to Asia and Africa, but since 2022, the virus has become widespread across Canada through the migration of wild birds.
In the U.S., the CDC has reported 66 cases of H5N1 in humans and one death associated with the infection. They have also detected almost 11,000 wild birds with the virus.
A Canadian Food Inspection Agency dashboard shows more than 3,400 positive samples of avian flu have been confirmed in wildlife in the country.
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