PROVO — A small flock of privately owned chickens in Utah County have tested positive with virulent Newcastle disease, a viral infection of the birds' respiratory, nervous and digestive systems and the first of its kind in Utah.

Three of the chickens were recently moved from southern California, which is experiencing an outbreak of the contagious and fatal disease that affects all species of birds, including poultry, but not humans.

The Utah Department of Agriculture and Food confirms that the disease has been contained to the one small domestic flock of 250 birds in Utah County.

The viral outbreak has sent more than 500,000 backyard and commercial chickens to their deaths in California, according to a recent industry-related publication. It was first detected there in May 2018 and more than 299 cases have been confirmed.

California State Veterinarian Annette Jones told AgNet West that wet and rainy conditions contributed to the spread of the disease.

Utah and federal officials are encouraging good biosecurity practices, including proper washing of hands, boots, tires and equipment before and after potential exposure to sick birds.

"The disease is spread when healthy birds come in contact with bodily fluids from infected birds and contaminated surfaces," Utah Department of Agriculture and Food State Veterinarian Barry Pittman said. The disease, he said, can be transmitted by contact with manure, egg flats, crates, farming materials or equipment, vehicles, or by people who have handled such materials, including touching their clothes, hands and shoes.

Virulent Newcastle disease, formerly called exotic Newcastle disease, does not pose a risk to humans, including eating an infected bird; but it does kill the birds, the Utah agency reports.

A 2002-03 outbreak reportedly cost the commercial poultry industry in California more than $165 million.

Symptoms of the disease, the agency said, include sudden death of the animals, sneezing or gasping for air, nasal discharge, coughing, green and watery diarrhea, drooping wings, tremors, circling and swelling around the eyes and neck. Even birds that have been vaccinated are susceptible to infection.

Owners of domestic poultry, including chickens, geese or ducks, who observe any unexpectedly sick or dying birds should call 801-520-4311 immediately so that the Utah Division of Agriculture and Food can help.

To report sick or dead wild birds in Utah, contact the Utah Division of Wildlife Resources in Springville, at 385-368-1128.