A teenager in British Columbia is in critical condition with a presumptive case of H5N1 avian influenza, marking Canada’s first human infection of this strain. The patient, reported to be otherwise healthy, developed symptoms shortly after exposure to pets but had no direct contact with infected birds or livestock. Health officials are investigating the transmission, emphasizing the low risk of human-to-human spread per the World Health Organization, despite international concerns regarding a rise in related infections. The patient is receiving antiviral treatment in a children's hospital.