Wastewater in several Californian cities, including San Francisco and Los Angeles, recently tested positive for bird flu. But understanding disease risk and exposure to humans isn’t so straightforward

State health officials said Tuesday night that they have detected H5 avian influenza, commonly known as bird flu, in wastewater test samples on Oahu.

A Canadian teenager infected with bird flu — that country’s first case involving a locally acquired infection — is in critical condition and experiencing difficulty breathing, health officials said Tuesday.

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.