How to control the avian flu outbreak

Since February 8, 15.6 million commercial and backyard birds across 17 states have been depopulated because of avian influenza infections. Once one bird has tested positive, the entire flock must be depopulated to reduce the spread of the disease.

Avian influenza, also referred to as bird flu, is a type A influenza that can affect all species of birds. There are two designations of avian influenza: highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza.

"The two are essentially the same virus, other than how they affect the birds and how contagious and deadly the strain is," says Dr. Yuko Sato, poultry extension veterinarian and diagnostician at Iowa State University. "The designation indicates how likely it is to kill the birds. It has nothing to do with how infectious the virus is for people or for other mammals."

HPAI can manifest in a variety of ways in commercial and backyard birds: dying without clinical signs; lack of energy; decreased egg production; soft-shelled or misshapen eggs; swelling or purple discoloration of the head, eyelids, comb, and hocks; nasal discharge; coughing; sneezing; incoordination; and diarrhea. The USDA has a resource with images to help identify discoloration and other clinical signs.

Usually, wild birds can carry HPAI without displaying symptoms and can introduce the virus to farms without raising concerns. However, Sato says this particular strain of HPAI, H5N1, appears to also be deadly to wild geese and ducks.

Since January 13, 482 wild birds have been reported to have HPAI. Wild bird detection is done through targeted sampling, Sato says. Hunters, landowners, and others call in when they suspect a bird has died from HPAI or is infected. The USDA has a list of specific geographic areas that have high mixing of wild bird populations in which they collect samples from.

"It's not really a matter of if another outbreak occurs, it's a matter of when," says Sato. "We've detected it. We've seen it in wild waterfowl, we've definitely seen it in commercial poultry. The only thing producers can do to prepare for this is to have good biosecurity."

Sato says the best way to think about biosecurity is keeping the outside out and the inside in. Controlling movement, educating workers on sources of infection, changing clothes and boots, showering in and out, and other basic standards of sanitation are great ways to mitigate infection points. Keeping in mind the ways that HPAI can spread—through saliva, nasal secretions, and feces—is also important.

HPAI is always fatal. There is no treatment, cure, or vaccination, so preventing the virus from entering the premises is the only way to keep your flock safe.

"It takes a village to control an outbreak," says Sato. "It's really a cooperation between the poultry industry and the state and federal levels. We are all pieces of the puzzle."