A highly virulent bird disease that can kill whole flocks of chickens in a day, but rarely infects humans, has been detected in Riverside County, health officials said Friday.

Newcastle disease — which causes a variety of symptoms in birds including coughing, greenish diarrhea, tremors, drooping wings, twisting of the head and neck, complete stiffness and swelling around the eyes and neck — was confirmed in a show chicken living in a northwest Riverside County backyard on June 30, county spokesman Ray Smith said.

“This disease is so virulent it could significantly affect the poultry industry nationwide if it reaches commercial flocks,” county Agricultural Commissioner Ruben Arroyo said. “We are taking extra precautions to reduce the risk of tracking disease on and off farms by limiting farm visits to those that are essential to health and safety.”

Smith said the disease has only ever been known to infect humans handling sick chickens, and even then it produces mild symptoms limited to conjunctivitis. Humans cannot become ill from eating well-cooked poultry from an infected chicken, he said.

Chicken owners were urged to take preventative measures to ensure their flocks do not contract the virus.

“Owners of backyard chickens should not buy new birds, trade their birds or move their birds until this matter is resolved,” said county Chief Veterinarian Dr. Allan Drusys.

In addition, county officials asked chicken owners to take the following precautions:

— do not move chickens from your home until the situation is resolved;

— restrict traffic onto and off of your property;

— disinfect shoes, clothes, hands, egg trays or flats, crates, vehicles and tires;

— avoid visits to other poultry farms or bird owners;

— wash hands and scrub boots before and after entering a poultry area; and

— isolate any birds returning from shows for 30 days before placing them with the rest of the flock.

Owners whose chickens die suddenly or show signs of illness were urged to call California’s Sick Bird Hotline at (866) 922-2473.

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