The rooster's owner, 10-year-old Ivy Lurz, had dropped him off at the 4-H club's booth in Tres Pinos on Oct. 2 to be shown in a competition two days later.

But when Ivy returned to the fair, she wasn't allowed to see her bird.

On Oct. 3, the California Department of Food and Agriculture ordered a statewide quarantine on all poultry as it began investigating an outbreak of Newcastle disease in Southern California.

The disease was identified two weeks ago in small flocks of "backyard" birds in Los Angeles County. And although the source of infection has not been identified, officials at the state Department of Food and Agriculture believe it was introduced by birds illegally smuggled into the country.

"When they are brought in like that, they are not inspected," said Leticia Rico, a spokeswoman for the Department of Food and Agriculture.

Newcastle disease is considered by epidemiologists to be one of the most infectious poultry diseases in the world. Like influenza, the severity of the disease can vary from mild, isolated cases to lethal forms that can wipe out entire flocks at a global scale.

Luckily for Ivy, Lex -- named after Lex van den Berghe of Santa Cruz, a participant of "Survivor: the Australian Outback" -- passed the state inspection and appears to be free of Newcastle. She and her rooster both won second place at the San Benito Fair.

5,300 birds destroyed

Birds in three Southern California counties weren't as fortunate.

The Department of Food and Agriculture said the strain has been identified on 19 premises in Los Angeles, San Bernardino and Riverside counties in its most virulent form, which state officials are referring to as exotic Newcastle disease. By Thursday, 5,300 birds had been destroyed in that three-county area.

In 1971, a global outbreak of the disease that affected California's commercial poultry. When the virus was finally contained in 1973, 1,341 flocks had been infected and more than 12 million birds were destroyed. The disease cost state taxpayers more than $56 million.

Newcastle disease is known to produce bloody lesions in the digestive tracts of birds and can affect their respiratory and nervous systems, too. While the most lethal forms of the disease have been known to kill 100 percent of an infected flock, death rates are usually much lower, with extreme cases killing of only 50 percent of adults in a population and 90 percent of the young.

The symptoms

Signs of infection include sneezing, coughing, nasal discharge, diarrhea, listlessness and sudden death.

The disease is not transmissible to humans. However, it is highly contagious between bird species. It is passed via bird-to-bird contact and by contaminated materials.

Linda Velasquez, acting health officer for Monterey County, said, "It is migrating season."

So far, the state has not detected signs of the outbreak in commercial poultry these populations, but it is taking precautions to prevent the infection from spreading to them.

Suspending all poultry exhibitions at state fair grounds, as well as stopping the movement and sales of backyard birds, are the first measures the state has taken.

But, even if the disease is contained soon, "it's always a good exercise to talk about diseases that could potentially get in the way of our food supply," Velasquez said.