H5N9 is “not commonly seen in poultry in general,” says Eman Anis, assistant professor at the University of Pennsylvania School of Veterinary Medicine. (Anis is part of a lab that conducts national testing of poultry samples for avian influenza.)

A new strain of a highly pathogenic and rare strain of bird flu has been reported on a duck farm in central California.

US officials are investigating the appearance of a strain of bird flu identified in the US for the first time, a worrying sign that the virus is evolving in ways that could make it harder to

The finding at a California duck farm is raising alarms among public health experts that bird flu could further mutate into “unpredictable new viruses.”

Nearly 119,000 birds have been culled at a farm in California after a bird flu called H5N9 was detected among the poultry

State officials say the highly pathogenic avian influenza – more commonly known as bird flu – is widespread in much of the state.