A British Columbia teenager has recovered enough to breathe without supplemental oxygen after her H5N1 avian flu infection. She is also no longer infectious, her doctors report. The case report appeared this week in the New England Journal of Medicine.
Specialists from the BC Centre for Disease Control signed the report. Colleagues at BC Children’s Hospital, the Public Health Agency of Canada and the province’s agriculture ministry joined them. Together they give the fullest timeline yet of the case. The patient is a 13-year-old girl from the Fraser Health region. She was previously healthy apart from mild asthma. Her illness then escalated within days from a fever and pink eye to respiratory failure. She spent weeks in intensive care as a result.
KEY POINTS
- She stopped being infectious on Nov. 29 and came off supplemental oxygen on Dec. 18, the case report says.
- She first went to an emergency room on Nov. 4, but doctors sent her home. She returned three days later in respiratory distress.
- Investigators still do not know how she caught the virus, and no one around her became ill.
A case of avian flu that escalated fast
According to the report, the girl first reached an emergency department on Nov. 4. She had fever and conjunctivitis in both eyes. Doctors discharged her without treatment. Her condition then worsened. A cough, vomiting and diarrhea developed. She returned on Nov. 7 in respiratory distress. The next day she moved to the pediatric intensive care unit at BC Children’s Hospital in Vancouver. There, doctors intubated her and treated pneumonia, kidney injury and respiratory failure. They used antiviral drugs and intensive supportive care, including plasma exchange therapy.
Her recovery, once it began, stayed steady. Doctors declared her no longer infectious on Nov. 29. She then moved from intensive care to a pediatric ward on Dec. 4. By Dec. 18 she no longer needed supplemental oxygen. She and her family also consented to releasing the clinical details, the report notes.
Background and context
The case landed in the middle of the worst avian flu season British Columbia’s poultry industry has ever faced. Since spring 2022, outbreaks of the H5N1 virus in its current form have culled more than 8.5 million farmed birds. The strain belongs to clade 2.3.4.4b. Most of the losses were in the Fraser Valley, where wild birds, commercial barns and backyard flocks sit close together.
Provincial health officer Dr. Bonnie Henry said in November that the virus belonged to genotype D1.1. That was the same strain then circulating in B.C.’s wild birds and poultry. It differed from the genotype found in American dairy cattle. The case report also flags the detail scientists are watching most closely. Genetic sequencing found changes of the kind associated with easier binding to human airway cells. However, no secondary infections appeared among her household or hospital contacts. Officials stress there is no evidence of human-to-human transmission. Still, the mutations explain why a single severe pediatric case drew attention from flu researchers worldwide.
South of the border, the United States recorded 66 confirmed human infections in 2024. Nearly all stayed mild and involved work with infected dairy cattle or poultry. The B.C. case stood out for its severity. It also stood out because investigators never found the exposure that caused it, despite searching her home, school and surroundings.
What happens next
Health officials say surveillance continues on both sides of the farm gate. They are testing poultry outbreaks in the Fraser Valley. Workers on farms also face regular screening. In addition, wastewater and clinical screening should catch any further human infections early. For the public, the advice is unchanged. People should not handle sick or dead wild birds. They should also keep pets away from them. They should report findings to provincial authorities as well.
The teenager’s own story continues out of the public eye. Still, what her avian flu case leaves behind is a clinical record. Hospitals internationally will study it the next time a severely ill child tests positive. It is a virus the world is watching.
Sources: Case correspondence published in the New England Journal of Medicine (Dec. 31, 2024) by BC Centre for Disease Control, BC Children’s Hospital, Public Health Agency of Canada and B.C. Ministry of Agriculture officials; B.C. provincial health officer statements.
