Bird flu virus likely mutated within Louisiana patient who became severely ill, CDC says PBS NewsHourBird Flu Samples From Very Ill Patient Had ‘Concerning’ Mutations The New York TimesBay Area counties ramp up outreach efforts after state-wide emergency over avian flu CBS San FranciscoGenetic Sequences of Highly Pathogenic Avian Influenza A(H5N1) Viruses Identified in a Person in Louisiana CDCCDC: H5N1 mutations in severely ill patient could boost spread, but risk remains low University of Minnesota Twin Cities