Avian metapneumovirus (AMPV), not highly pathogenic avian influenza (HPAI), is the likely cause of low U.S. inventories of turkey eggs in incubators, the National Turkey Federation (NTF) said.
“I think it’s important to know that avian metapneumovirus has been seen in every poultry producing state in the U.S. It is being detected in a large amount of turkey operations and it is widespread,” said Lindy Chiaia, Ph.D., vice president of scientific and regulatory affairs, NTF.
In addition, NTF estimates that the virus is present in 60-80% of U.S. turkey flocks, with over 1,500 detections since February 2024, Chaia added.
“In the U.S., we’ve seen a shortage of eggs to set in the hatcheries and mortality has resulted in a shortage of birds to send to the processing plants, so it has been kind of a double whammy on the turkey industry,”” David Rives, DVM, DACPV, senior technical services veterinarian, Zoetis, said.
The U.S. Department of Agriculture (USDA) does not officially track avian metapneumovirus cases, which complicates data collection.
More about AMPV
AMPV can induce highly contagious respiratory disease in all species of commercial poultry, as well as wild birds, and result in a drop off in egg production and quality in layers and broiler and turkey breeder hens. Respiratory symptoms include ocular and nasal discharge, frothy eyes, conjunctivitis, swollen sinuses, sneezing and coughing, depression and ruffled feathers.
Diagnosis of AMPV can be challenging because many of the symptoms mimic that of other upper respiratory diseases in poultry, added Rives.
While AMPV is grouped in subtypes A to D, strains A & B are the root of a nearly all cases present in the United States.
Lobbying for vaccine approval in the US
There is no current regulatory approval for a live AMPV vaccine in the U.S., however outside the U.S., both live and inactivated vaccines are commonly used to immunize chickens and turkeys against avian metapneumovirus.
“We have not had U.S. approved vaccines simply because we have not seen this virus circulating the U.S. in almost 20 years. I think it’s important to know that, while other parts of the world have been seeing this disease, they’ve had tools to protect them. Because it’s an emerging situation, that is the key reason why we don’t have a U.S. manufactured vaccine,” Chaia explained.
“We see a big need to allow the import of these modified live vaccines to address the immediate need and protect turkeys now with the long-term strategy of a domestic vaccine.”
Some U.S. lawmakers are attempting to change that. “As you continue to evaluate potential treatments, it is critical that a safe, effective vaccine is approved as soon as possible,” a bipartisan group of 11 U.S. senators wrote in an August 29, 2024 letter to U.S. Secretary of Agriculture Tom Vilsack.
The group, led by Amy Klobuchar (D-MN) and John Boozman (R-AR), also urged the emergency use approval to use an imported commercial modified-live AMPV vaccine. Outside the U.S., both live and inactivated vaccines are commonly used to immunize chickens and turkeys against avian metapneumovirus.
