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.

Rose Acre Farms, the nation's second largest egg producer, said yesterday that tests have confirmed avian flu at its facility in Seymour, Indiana, which could further stretch the supply of eggs as commercial farms in several states continue to battle the spread of the H5N1 virus.

The first U.S. H5N9 outbreak has raised concerns as scientists warn of evolving bird flu risks—here's what you need to know about the symptoms.

The United States has reported its first H5N9 bird flu outbreak in California, affecting almost 119,000 ducks. Both H5N9 and the more common H5N1 strains were found. The USDA is conducting investigations and enhanced surveillance,

Due to ongoing sporadic H5N1 avian flu infections and brisk levels of seasonal flu activity, the US Centers for Disease Control and Prevention (CDC) today urged healthcare providers to subtype all influenza A specimens in hospitalized patients, especially those in the intensive care unit (ICU), as soon as possible.

Samples taken from a backyard flock have confirmed the presence of H5N1 bird flu, also known as highly pathogenic avian influenza (HPAI), in Windsor County. This case was confirmed on January 21st by Vermont’s Agency of Agriculture,

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.

The first confirmed case of H5N9 bird flu in the United States has been identified in Merced County, California, and control measures are being undertaken to contain the virus.

This is the fifth instance of HPAI impacting a domestic flock in Vermont since spring of 2022 and emphasizes the ongoing need for vigilance as the disease continues to be an ongoing risk to domestic birds. This case comes on the heels of another HPAI confirmation in a flock of backyard birds in Franklin County this past December.

A deadly variant of the three-year outbreak of bird flu has found its way to Sampson County.

In patients with catheter-associated asymptomatic bacteriuria caused by multidrug-resistant Pseudomonas, antibiotic treatment was a significant risk factor for subsequent infection.

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