Fast Facts: What is Avian Influenza?

A human contracted avian influenza from a cow in March 2024. The transmission was the first of its kind, marking a new development in highly pathogenic avian influenza (HPAI). 

The HPAI virus was originally identified in domestic waterfowl in southern China in 1996. Subsequent poultry outbreaks of the virus in China and Hong Kong spilled over to humans, causing more than 860 human infections with more than a 50 percent death rate, according to the U.S. Centers for Disease Control and Prevention (CDC).

Since then, these viruses—known as H5N1—have spread across the globe to Africa, Europe, the Middle East, and North America in 2021.

“In February 2022, the virus begins causing outbreaks in U.S. commercial and backyard poultry,” the CDC explains. “Rare, sporadic human infections with this H5N1 virus are detected, as well as sporadic infections in mammals.”

But what exactly is avian influenza, and how does it spread? Watch the video below to find out.