What Is Avian Flu in the United States
Avian influenza, commonly called bird flu, is a viral infection that primarily affects wild birds and poultry. In the United States, highly pathogenic avian influenza (HPAI) strains such as H5N1 have caused outbreaks in commercial and backyard flocks. The U.S. Department of Agriculture tracks cases and responds with quarantine and depopulation measures to limit spread.
How Avian Flu Spreads and Is Monitored
The virus spreads through contact with infected birds, their droppings, or contaminated equipment. Migratory waterfowl can carry the virus across states. Federal and state agencies, including the Centers for Disease Control and Prevention, monitor wild birds, poultry flocks, and occasional mammalian infections. Surveillance programs test samples and report findings to national animal health authorities.
Human Risk and Public Health Response
Human infections with avian flu in the U.S. are rare but have occurred, usually after direct exposure to infected birds. Symptoms can range from mild respiratory illness to severe complications. The CDC provides guidance for poultry workers and the public, recommends personal protective equipment, and coordinates with state health departments. Early detection and reporting help reduce transmission risk.
For current case counts and guidance, visit the USDA Animal and Plant Health Inspection Service avian influenza page.
