B.C. teen with Canada's first human case of avian flu no longer in ICU

Chickens are seen at a poultry farm in Abbotsford, B.C., on Thursday, November 10, 2022. (Darryl Dyck / The Canadian Press)

The B.C. teenager who became infected with Canada's first human case of H5N1 avian influenza was transferred out of intensive care and taken off supplemental oxygen last month.

While health officials have not provided any updates on the case since November, new details were published Tuesday in the New England Journal of Medicine, in a report signed by doctors from the Public Health Agency of Canada, the B.C. Centre for Disease Control, and B.C. Children's Hospital.

The patient – described as a 13-year-old girl with mild asthma – was initially taken to an undisclosed emergency department on Nov. 4 with a fever and conjunctivitis.

She was sent home without treatment, only to be brought back to hospital three days later in "respiratory distress," according to the case report. The teenager was then transferred to the ICU at B.C. Children's, suffering from pneumonia, acute kidney injury, thrombocytopenia, leukopenia and respiratory failure.

She remained in intensive care until Dec. 4, when she was transferred to the hospital's pediatric ward. By Dec. 18, she no longer required supplemental oxygen.

Provincial officials announced the child's infection on Nov. 9 – after the presence of the H5 influenza virus was confirmed through testing – and launched an investigation into how and where she acquired the disease.

The government did not share any personal details on the patient at that time, except that she is from B.C.'s Fraser Valley. The report published in the New England Journal of Medicine this week indicates both the patient and her family consented to releasing additional details on her case.

The Ministry of Health told CTV News it could not provide any further information on Wednesday, including whether the child remains in hospital.

Provincial health officer Dr. Bonnie Henry announced the findings of the government's investigation on Nov. 29, confirming they had found "no evidence of transmission" from the child, and "no evidence of other cases" in B.C. either.

The source of the teenager's infection was never established, however, despite the testing of dozens of animal and environmental samples, all of which came back negative. Henry said the investigation was closed, at least temporarily, for lack of additional leads.

Genome sequencing did indicate the virus was the same one "circulating among poultry and wild birds" in both B.C. and Washington state since October, and "recently detected in a severe human infection in Louisiana," according to an appendix posted with the case report on Tuesday.

The doctors also noted there was evidence of a "worrisome" genetic mutation that "may increase binding to human airway receptors."

There have been 66 human cases of H5N1 confirmed across the U.S. so far, including 11 in Washington state, according to the U.S. Centers for Disease Control, which considers the overall public health risk to be "low." There have been outbreaks of the virus among poultry in all 50 states.

B.C.'s Ministry of Health advises anyone who has been exposed to sick or dead animals, or who works on a farm where avian influenza has been detected, to watch for flu-like symptoms. If those symptoms develop within 10 days of exposure, officials recommend telling a health-care provider.

With files from CTV News Vancouver’s Kaija Jussinoja and Michele Brunoro