Scientists say a concerning genetic mutation has appeared in H5N1 bird flu infected cats living in a New Jersey suburb of New York City

Mutated H5N1 Bird Flu Found in Cats: Scientists have identified a genetic mutation in two infected cats that is linked to increased infectiousness and disease severity. Mutation Similar to One Found in Cows: The mutation, PB2 E627K, is similar to one found in San Bernardino dairy cows, though the cats were infected with a different strain.

Two cats in separate New York City households have tested positive for bird flu, the city health department says.