H5N1 avian influenza, more commonly known as bird flu, has infected more than 100 million birds in the U.S. and almost 500 dairy cattle herds across 15 states. The virus has popped up in mammals including elephant seals,

Health officials on Wednesday confirmed bird flu in a British Columbia teen and said the virus was related to a poultry outbreak in the province. Initial testing had indicated the teenager’s infection was from bird flu and was confirmed in further testing,

A Canadian teenager is hospitalized in critical condition with bird flu, health officials reported Tuesday. The teen has been receiving care at BC Children’s Hospital in Vancouver since Friday, the same day an initial test came back positive for H5 influenza.