Nation's Ongoing HPAI Epidemic

By Andi Anderson

The nation finds itself entrenched in the third year of its most extensive highly pathogenic avian influenza (HPAI) outbreak ever recorded. Despite this, the U.S. Department of Agriculture (USDA) remains committed to evaluating potential vaccines that have shown promise in safeguarding chickens against this lethal illness. Researchers are also investigating the unusually virulent nature of the current circulating strain. 

Since January 2022, HPAI has impacted millions of wild birds, commercial poultry flocks, and various mammal species across the globe, reaching Africa, Asia, the Americas, Australia, Europe, and even Antarctica. The primary culprits behind most infections have been identified as the Eurasian (EA) H5 and H5N1 subtypes of the HPAI A virus. 

The outbreak's extensive spread and the broad spectrum of affected wildlife outlined in a 2023 report by the Food and Agriculture Organization (FAO) highlight the urgent need to curb new strain proliferation and limit further infection waves. 

In the United States, the virus has been detected in wild birds across the nation, excluding Hawaii. To date, over 72 million birds across 47 states have been affected, including commercial and backyard poultry flocks, and even certain mammal species such as mountain lions and red foxes. 

The USDA's Agricultural Research Service (ARS) has made significant strides in testing five HPAI vaccine candidates, showing promising results in reducing viral shedding and ensuring high clinical protection in chickens. Despite these advancements, challenges persist concerning international trade restrictions and the differentiation of vaccinated flocks from those exposed to the virus. 

While vaccines offer hope, Dr. David Swayne, a former USDA official, emphasizes that proper biosecurity measures remain crucial in combating HPAI. He encourages bird owners to review and enhance their biosecurity protocols to minimize exposure to wild birds and mitigate the risk of infection. 

As efforts continue, the USDA remains cautious, stressing the importance of a multifaceted approach to combatting HPAI effectively. 

Photo Credit: gettyimages-branex