H5N9 is a rare subtype of the influenza A virus that can cause highly pathogenic avian influenza (HPAI), also known as bird flu. It's a reassortment strain that originated from the H5N1, H7N9, and H9N2 subtypes.

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

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

The first positive HPAI case in Pennsylvania was found within a Lehigh County commercial layer chicken flock, according to the Shapiro Administration. Here's what you shoiuld know.

Commercial duck flock in California has tested positive for two strains of avian influenza. On November 23, 2024, two HPAI viruses were identified in samples from a farm rearing meat ducks in Merced County in California. Increased mortality was observed at the premises, leading the state veterinary authority to quarantine the farm.

Lithuania has reported an outbreak of highly pathogenic H5N1 avian influenza, commonly called bird flu, on a laying hen farm in the western part of the country, the World Organisation for Animal Health (WOAH) said on Wednesday.