There are 10 million commercial laying hens, and approximately 100,000 backyard chicken owners, in the state of California. The California Department of Food and Agriculture is charged with protecting all those chickens and one of their biggest challenges comes from Virulent Newcastle Virus, a foreign animal disease with no cure and close to a 100% death rate in unvaccinated flocks.
During the first major outbreak of the virus in 2002, nearly 2 million birds were destroyed to stop the spread of the highly contagious disease. Last summer, Newcastle Virus returned to California, and the U.S. Department of Agriculture (USDA) asked the Oregon Veterinary Diagnostic Laboratory (OVDL) to help.
When a large-scale animal-disease outbreak occurs, the USDA relies on laboratories managed by state governments and universities to collaborate with them on disease surveillance and testing. In July 2018, the OVDL responded to a request for help with Newcastle Virus by loaning Medical Laboratory Technician Janna Thorp to the California Health and Food Safety Lab (CAHFS) where overwhelmed staff had been processing hundreds of test samples pouring into the lab every day.
Commercial poultry growers use kits to regularly test their flock for Newcastle Virus, and send the samples to CAHFS. When a serious outbreak occurs, a task force sends teams out with warrants to test backyard chickens too. “Last July, they established that the outbreak started in backyard flocks,” says Thorp. “That is due to lack of knowledge. Commercial managers carefully follow antiseptic practices, but backyard growers often don’t know how.”
Because Newcastle Virus is so contagious, the task force wants results quickly. “A courier picks up the shipped sample in middle of night,” says Thorp, “so that it will arrive at the lab by 8 am.” Thorp then preps the samples for molecular diagnostic testing. Any positive test requires a retest, then it is same-day emailed to Iowa for confirmation at the national lab. “The whole process is hugely expensive,” says Thorp. “But it’s an urgent situation with potentially serious consequences.”
This March, Janna Thorp was asked to return to CAHFS to help.
For ten months, the California Department of Agriculture had tested, quarantined, and shut down farms that didn’t meet biosecurity standards, but they still hadn’t controlled the disease. In March, a veterinarian from the San Francisco bay area brought a chicken in to the lab for necropsy; he was treating a backyard flock of sick birds. The bird tested positive for Newcastle Virus. “So apparently Newcastle disease had jumped from the 4-county containment near L.A. to the bay area,” says Thorp. “That changed everything. They were running around like crazy.”
In April, the California state veterinarian ordered mandatory euthanasia of all chickens in the four counties. In the past two weeks, nearly half a million chickens have been destroyed. Although the farmers are compensated by the state, the mass-euthanasia will have long-term economic consequences on California.
Thorp is now back at the OVDL, trying to catch up. “When just one person is gone, we get behind,” she says.
