A virus that kills poultry or makes them severely ill has been detected in Washington for the first time.

The Infectious Bursal Disease Virus (IBDV) affects the immune systems of chickens, causing their bodies to become more susceptible to other diseases. The virus was detected this month in a flock of chickens on a Washington farm, marking its first occurrence in the state.

“One to two percent of birds with this virus die, but most survive and become immune-suppressant,” said Tim Baszler, the director of the Washington Animal Disease Diagnostic Laboratory in Pullman. “With the new very virulent form of IBDV, mortality of birds infected increase to thirty percent.”

Cases of the very virulent form of IBDV (vvIBDV) have been detected since the late 1980s in parts of Asia, South America, Europe and the Middle East. The first documented case in the U.S. occurred in California in December 2008.

“At this time, it is unknown how the virus came to our state,” said Rocio Crespo, the branch chief of the WSU Avian Health and Food Safety Laboratory in Puyallup. “As of today, only one farm has been diagnosed with vvIBDV in Washington.”

Symptoms of the disease include death, depression, ruffling of feathers, poor appetite, huddling, unsteady gate, and diarrhea. As a result, the disease can be confused with others that affect poultry.

 “There would be legions in the autopsy which gave suspicion to the virus,” Baszler said. “Then, samples were taken from organs, and that’s when you know for sure.”

The virus mostly affects chickens less than 17 weeks old, and those between three and six weeks old are most susceptible to disease, Crespo said.

Wild birds, including healthy ducks, guinea fowl, quail and pheasants, often carry IBDV but are not considered significant in spreading the disease to domestic poultry. The virus is not known to be a human pathogen and is not transmitted through the consumption of chicken or eggs.

Baszler added that the virus is not airborne.

“It is transmitted through the oral-fecal route, which is why we ask farmers to monitor their biosecurity,” he said. “Fecal matter from infected birds can be transmitted from traffic coming into your farm. It can be brought in from your boots, car tires, coveralls or birdcages.”

Chickens can then ingest the contaminated feces and become infected themselves.

The Washington State Department of Agriculture quarantined the infected flock to prevent the virus from spreading.

“There are vaccinations for certain bird diseases – but they aren’t always 100 percent effective,” said Mike Louisell, a public information officer for the department. “Owners should clean and disinfect tools and keep clean flock houses.”

Crespo said if farmers don’t actively control the virus, it might impact prices of chicken meat and eggs.

“IBDV is not known to infect people or other animals,” she said. “It is not a food safety problem. However, it may increase the cost of production.”

Crespo said farmers should contact a veterinarian if they notice illness or sudden deaths among their flocks.

“We want your poultry to be safe and healthy,” Crespo said. “If you see anything unusual, contact your vet or call the diagnostic lab. The labs have a variety of tools to recognize the cause of death and accurately identify the virus.”