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Avian Influenza

Scientific Name

Orthomyxoviridae, Influenza Type A (CABI)

Common Name

Highly pathogenic avian influenza (HPAI), fowl plague

Native To

First noted in Italy in 1878 (CABI)

Date of U.S. Introduction


Means of Introduction

Projected to arrive in the U.S. in migratory birds or through poultry imports (Global Invasive Species Database 2005)


Infects poultry, waterfowl, and occasionally mammals (including humans) (CABI)

Current U.S. Distribution

Not currently established in the U.S.

Avian influenza

Avian influenza, ARS scientists are working to improve vaccines and technology to help control bird flu


Photo by Stephen Ausmus; USDA, ARS Image Gallery

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  • USDA Confirms Highly Pathogenic Avian Influenza in a Wild Bird in South Carolina

    • Jan 14, 2022
    • USDA. Animal and Plant Health Inspection Service.

    • The United States Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed highly pathogenic Eurasian H5 avian influenza (HPAI) in a wild American wigeon in Colleton County, South Carolina. Eurasian H5 HPAI has not been detected in a wild bird in the United States since 2016. There was a case of HPAI (H7N3) in one commercial meat turkey flock in South Carolina in 2020 due to a North American lineage virus. The Centers for Disease Control and Prevention considers the risk to the general public from HPAI H5 infections to be low. No human infections with Eurasian H5 viruses have occurred in the United States. As a reminder, the proper handling and cooking of poultry and eggs to an internal temperature of 165˚F kills bacteria and viruses, including HPAI.

      Anyone involved with poultry production from the small backyard to the large commercial producer should review their biosecurity activities to assure the health of their birds. APHIS has materials about biosecurity, including videos, checklists, and a toolkit available at the Defend the Flock Resource Center.

  • USDA Increases Efforts to Protect U.S. Poultry and Expands Wild Bird Surveillance for Avian Influenza

    • Feb 11, 2022
    • USDA. Animal and Plant Health Inspection Service.

    • The United States Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) is announcing the expansion of wild bird surveillance for avian influenza to include the Mississippi and Central Flyways. This expansion also enlarged the existing surveillance program in the Atlantic and Pacific Flyways, which is in place to conduct surveillance of birds that may interact with wild birds from Europe and Asia. APHIS confirmed highly pathogenic avian influenza (HPAI) in wild birds in several states in the Atlantic Flyway in January as well as in a commercial turkey flock in Indiana on February 8, and this additional surveillance will increase our capability to track the disease throughout the United States.

      Anyone involved with poultry should review their biosecurity plan and enhance their biosecurity practices to ensure the health of their birds. APHIS has materials about biosecurity, including videos, checklists, and a toolkit available on the Defend the Flock Resource Center. In addition to practicing good biosecurity, all bird owners should prevent contact between their birds and wild birds and report sick birds or unusual bird deaths to state/federal officials, either through their state veterinarian or through USDA's toll-free number at 1-866-536-7593. Additional information on biosecurity for backyard flocks can be found at

      See also: 2022 Detections of Highly Pathogenic Avian Influenza for related news of the Eurasian H5 HPAI in the U.S.

  • Avian Influenza Research Sheds Light on Possible Routes of Introduction to North America

    • Apr 22, 2022
    • DOI. USGS. National Wildlife Health Center.

    • Understanding how wild birds facilitate the maintenance, reassortment, and dispersal of influenza A viruses (IAV) is key to forecasting global disease spread. The current highly pathogenic avian influenza outbreak in North America highlights the question of how viruses are transported between continents. Recent NWHC research sheds light on this question and the potential role Iceland may play.

  • Secretary Vilsack Approves Additional Funds to Support Highly Pathogenic Avian Influenza Response

    • May 27, 2022
    • USDA. Animal and Plant Health Inspection Service.

    • USDA’s Animal and Plant Health Inspection Service (APHIS) continues its efforts to respond to an outbreak of highly pathogenic avian influenza (HPAI) in the United States. To date, the virus has been confirmed in 35 states, affecting more than 37.9 million domestic birds. APHIS’ response efforts include working closely with animal health officials in affected states to quickly identify and address new cases of HPAI. To help ensure APHIS can continue to provide critical rapid response activities, Agriculture Secretary Tom Vilsack approved the transfer of $400 million from the Commodity Credit Corporation to APHIS to directly support the response efforts.

      While these response efforts are vital to ending the outbreak, there are also actions bird owners can take to help stop the spread of this virus. APHIS has a variety of biosecurity resources available along with more information for bird owners.

  • Protect Your Poultry From Avian Influenza [PDF | 977 KB]

    • Oct 2019
    • USDA. Animal and Plant Health Inspection Service.

    • Avian influenza, or "bird flu," is a respiratory disease of birds caused by influenza A viruses. These viruses can infect domestic poultry (such as chickens, turkeys, ducks, and geese) and are found naturally in wild birds (such as ducks, gulls, and shorebirds). Low pathogenic avian influenza (LPAI) occurs naturally in wild birds and can spread to domestic birds. In most cases, it causes few or no outward signs of infection. LPAI viruses are common in the United States and around the world. High pathogenic avian influenza (HPAI) is extremely infectious, often fatal to domestic poultry, and can spread rapidly from flock to flock. If HPAI is found in the United States, we must eradicate it to protect our country’s flocks and to keep trade flowing.

Distribution / Maps / Survey Status

Federally Regulated


Selected Resources

The section below contains highly relevant resources for this species, organized by source.

Federal Government
International Government
State and Local Government