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.

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

U.S. authorities also detected the more common H5N1 strain on the same farm in Merced County, California, they said in a report to Paris-based WOAH, adding that the almost 119,000 birds on the

Since early 2024, the U.S. has logged 66 human cases of H5N1. Scientists are keeping a watchful eye on the virus’s spread as we enter a new year.

The H5N1 virus has a ways to go before it can successfully jump to humans but that it doesn’t reduce the threat it poses.

The findings come at a time when outbreaks of bird flu -- a different subtype of the ... of the highly pathogenic avian influenza (HPAI) H5N1 influenza virus currently circulating

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

According to the Centers for Disease Control and Prevention, 67 people in the U.S. have been infected with H5N1 bird flu. One person has died.

H5N9 and H5N1 are two strains of bird flu that have recently sparked concern, especially after a significant outbreak at a California duck farm. Both strains are highly pathogenic, affecting poultry and wild birds,

The H5N9 strain of avian influenza is much more rare than the H5N1 which has been responsible for most of the reported human cases and the first human death.

A new strain of bird flu has been confirmed at a duck farm in California, the first time the variant has been discovered in poultry in the United States, an