Rapid END Testing

EurekAlert, DC


Public release date: 13-Mar-2003
Contact: Stephen Wampler
University of California - Berkeley
Exotic newcastle disease

LIVERMORE-- Newly developed rapid diagnostic assays to detect exotic Newcastle disease developed by a partnership of researchers at Lawrence Livermore National Laboratory and other institutions have "significantly aided" containment of the poultry disease. That's the view of professor Alex Ardans, director of the California Animal Health and Food Safety Laboratory based at the UC Davis School of Veterinary Medicine.

Design and development of the assays have been done by a team from the Laboratory, the California Animal Health and Food Safety Laboratory (or CAHFS) at UC Davis and the U.S. Department of Agriculture.

At the time of the outbreak of exotic Newcastle disease last October in California, available assays to identify the disease required 6 to 12 days, according to Ardans.

A key signature that allows identification of the virus within four hours of receiving the sample was facilitated by a genomic-approach developed by an eight-member LLNL team, led by Paula McCready.

"The ongoing collaboration between LLNL and UC Davis doesn't only benefit the state of California, but also the nation," Ardans said. "The Livermore approach to developing assays for microbial diseases is being embraced nationwide."

The rapid tests are being used to assist state and federal exotic Newcastle disease task force personnel in disease detection and control efforts.

During the past five months, almost 3 million commercial egg-producing chickens have been euthanized in California because of exotic Newcastle disease. Additionally, more than 100,000 game birds and backyard poultry also have been euthanized.

Currently, seven counties, all in Southern California, are under quarantine, with a prohibition on moving poultry such as chickens, turkeys, geese, partridges and other birds.

Ardans believes federal and state agriculture officials are making headway in the fight against exotic Newcastle disease. During the past two weeks, the number of new cases of infected "backyard birds" seems to be decreasing in some areas, he noted.

A highly lethal viral ailment, exotic Newcastle disease affects poultry, causing respiratory problems and lethargy. Chickens are particularly susceptible to the disease and usually die within a few days.

"With the faster detection method, we can rapidly identify the affected animals and isolate them before the disease spreads further," said McCready.

"If an outbreak is not quickly contained, it spreads rapidly, affecting the state's poultry industry and its ability to trade with other states and countries."

Laboratory researchers were contacted by CAHFS on Oct. 13, and within days had generated possible target signatures for development of a rapid assay.

LLNL biomedical scientist Evan Skowronski worked with CAHFS staff at UC Davis over the next two months to optimize performance of the assays and pioneer ways to rapidly process hundreds of samples per day. Skowronski was instrumental in sequencing the first viruses isolated from commercial flocks to confirm the accuracy of the assay.

In addition to disease identification in affected birds, the rapid test is now being used routinely in surveillance efforts in unaffected commercial flocks to assure their disease-free status.

These efforts involving nearly 600 different poultry houses will continue after the outbreak is contained as a disease surveillance program to demonstrate that the state is free of the disease.

"We were able to make a rapid response to an outbreak of an emerging disease," said McCready, who is associate program leader for biology in the Chemical and Biological National Security Program.

The team's computations group, led by Tom Slezak, used unique software developed by Laboratory researchers to identify a target sequence to distinguish the highly virulent forms of the virus from other forms.

This has been extremely useful in the rapid differentiation of exotic Newcastle disease virus from closely related Newcastle disease viruses used in vaccines or those causing less severe disease.

"To the best of our knowledge, this is the first working rapid assay for Newcastle disease to be adapted for routine diagnostic and surveillance use," McCready said.

The development of this exotic Newcastle disease signature and the additional work required to ready it for use was paid for with Laboratory Directed Research and Development money, a Laboratory fund for cutting-edge research.

In addition to McCready, Skowronski and Slezak, other members of the Laboratory assay development team include bioinfomatics scientists Beth Vitalis, Tom Kuczmarski and Shea Gardner, along with biomedical scientists Shanavaz Nasarabadi and Jason Olivas. Funded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy's National Nuclear Security Administration.

Tri-Valley Herald, CA

Article Last Updated: Friday, March 14, 2003 - 3:11:25 AM PST


DNA test might be able to save state's fowl
Test for bioterror attacks may help stem Newcastle disease
By Ian Hoffman, STAFF WRITER

With an exotic virus crippling state poultry exports to Europe and 23 countries, animal-health authorities are pinning new hope of stemming Newcastle disease on a DNA testing method originally pioneered for detecting bioterror attacks.

For weeks, Southern California poultry ranchers and backyard bird-raisers have watched as state and federal authorities in white suits destroyed 3.1 million birds suspected of carrying the highly lethal virus.

Exotic Newcastle disease poses no threat to humans and poultry products and hasn't yet passed the Tehachapi mountains into Northern California. But it threatens to outrun efforts at containment and, according to U.S. Agriculture Secretary Ann Veneman, "constitutes a real danger to the national economy."

In the six to 12 days needed for a typical lab test to identify infected birds for eradication, the virus has drifted farm to farm, yard to yard, hitching a ride on the wind, trucks, shoes and perhaps even the gear of vaccination workers.

Now scientists at UC Davis, Lawrence Livermore Lab and the U.S. Department of Agriculture have devised a faster, more precise test based on DNA-finger- printing methods that Livermore perfected for sniffing out plague, anthrax and other dangerous human pathogens. Results are available overnight.

"As far as I can tell, it is a very good and accurate test. It has high specificity and high sensitivity," said Dr. Greg Cutler, a Southern California veterinarian who credits the new test with saving a ranch flock from eradication.

The California Animal Health and Food Safety Laboratory at UC Davis is running up to 200 of the new tests a day as state and federal experts check more flocks. They are moving into Stanislaus and Fresno counties, where growers for poultry giants Tyson Foods and Holly Farms raise broilers and egg-laying chickens.

"The faster we can detect and move into control, the less economic impact this disease is going to have," said Sharon Hietala, a professor of clinical immunology at the Davis lab and co-developer of the test. "If we can respond more rapidly to the infection, the California Department of Food and Agriculture can make decisions to contain, quarantine or destroy the flock in days instead of weeks."

The test relies on polymerase chain reaction or PCR, a common method of multiplying and analyzing DNA in great detail. Livermore scientists use powerful computers to compare the DNA sequences of pathogens with those of close genetic kin. Further experiments nail down the DNA regions or "signatures" that are unique to the pathogen. Scientists then draw up an assay or recipe that includes fluorescent probes that light up to signal the segments' presence.

Livermore assays are the underpinning of the Bush administration's new Bio-Watch system, a network of biodetectors being installed on air-pollution monitors in 20 major U.S. cities.

The task was a little different with exotic Newcastle disease, because its chromosome is made of RNA rather than DNA and because close cousins of the virus were hard to find.

"These are very interesting creatures," said Paula McCready, head of Livermore's DNA signature team. "They mutate very quickly so it's very difficult to find those regions that are unique to the virus."

With a PCR test, McCready said, "We can find out whether the organisms are gone and can certify when we have a disease-free state."

The test spared 170,000 layer hens in Riverside County that USDA officials had slated for "depopulation" or euthanasia. The standard test, in which lab workers inject tissue of potentially infected birds into eggs and wait for the virus to multiply inside, showed the birds had a virus in the same family as exotic Newcastle.

"Everyone was all upset, saying, 'Hey, we've got Newcastle here,'" recalled Cutler, the rancher's vet. "They had already quarantined the place and they were looking toward depopulating. I said, 'Hey, wait, let's look at the real-time PCR.'"

Tissue samples were flown to Davis and tested in Hietala's lab. The results showed the presence of a nonvirulent vaccine strain, as Cutler suspected, not exotic Newcastle disease.

"Within four hours we knew it wasn't exotic Newcastle disease," Cutler said.

The test itself costs about $7.50 to perform. Cutler figures it saved the federal government about $850,000 in payment to the rancher for his birds.

Contact Ian Hoffman at ihoffman@angnewspapers.com

Contra Costa Times, Contra Costa County

Posted on Fri, Mar. 14, 2003


Test finds bird virus quicker
By Taunya English

LIVERMORE - A rapid-read test developed by scientists from Lawrence Livermore Laboratory and UC Davis is one of the newest tools in the fight to curtail the spread of an infectious bird virus that has caused poultry quarantines in Southern California and Nevada.

Exotic Newcastle disease is highly contagious and nearly always fatal to birds but does not threaten human health, according to the California Department of Food and Agriculture.

The "no movement" quarantine is pinching California's $1.4 billion poultry industry and has affected 17 production facilities. Scientists hope the tests can be used to routinely screen unaffected poultry flocks once Newcastle disease has been fully checked.

"The industry is huge in California and we are a food supplier nationally and internationally," said Livermore lab geneticist Paula McCready. To get back in business, "you have to prove your area and animals are disease-free."

Since exotic Newcastle struck Southern California in October, nearly 3 million commercial egg-producing chickens have been euthanized statewide. By February the disease containment effort reached $35 million, the agriculture department reports.

When Newcastle first struck, the standard screening method required that a specimen from a bird be inoculated in eggs for days before it could be analyzed. The new Livermore lab and UC Davis technique can recognize the virus from the barest essentials of a specimen and cuts the detection time to just four hours.

Exotic Newcastle spreads rapidly through bird droppings, breath and eggs and can decimate a flock. Chickens are especially susceptible to the disease and the respiratory problems and lethargy that accompany the illness.

Before 2002, the disease had not been found in the United States since 1971.

Sharon Hietala, a professor with the California Animal Health and Food Safety Laboratory at the UC Davis School of Veterinary Medicine, calls exotic Newcastle the "foot-and-mouth disease of the poultry industry."

Detection delays equate to lags in isolating infected animals and controlling the disease. Delays also result in more reimbursements to farmers whose animals or eggs are destroyed.

UC Davis and Livermore lab have a long-standing relationship, but in this case the lab harnessed its human genome and homeland-security bioterrorism expertise to focus on the problem of finding a quicker detection method for the bird virus.

McCready said her team looked for genetic markers unique to the exotic Newcastle virus but different from other Newcastle viruses endemic to the United States. The accuracy of the rapid, genomic-approach test was also verified through sequencing, or identifying particular pieces of DNA.

Hundreds of bird specimens are tested with the new technique each day, Hietala said. And those rapid tests are being validated with the older inoculation methodology, she said. With each identical result, the evidence mounts that the scientists have developed a dependable, low-cost and speedy detection test.

Since October, two rapid tests have been developed; one of them to pinpoint the highly pathogenic Newcastle virus.

Authorities recently quarantined a flock of Southern California birds that officials suspected where infected with Newcastle. But before the birds were killed, the rapid test uncovered the vaccine strain and avoided a near $1 million indemnity for the flock.

"You can imagine the relief that farmer felt," she said.

Reach Taunya English at 925-743-2216 or tenglish@cctimes.com.

The Signal, CA

(Note: Question Marks appear in original story)
Birds Euthanized Due to Outbreak

Brian Franks [Signal Staff Writer]

A 1-kilometer area around William S. Hart Park in Newhall is under quarantine for the exotic Newcastle disease, after an outbreak forced the destruction of the park?s captive birds, officials said.

On Wednesday and Thursday, all birds in the park?s barnyard area were destroyed because some tested positive for the disease. Many more birds may have to be killed; over the next several days, federal officials plan to go door-to-door in the area surrounding the park to determine if additional birds must be destroyed.

Hart Park Superintendent Norm Phillips said he and his staff are mourning the loss of the park?s 37 birds, which had been quarantined from the public since December. The park?s birds included 19 chickens, seven ducks, seven geese, three turkeys and a pheasant. A wild bird that was being housed at the park as confiscated evidence was also destroyed.

?It is very disheartening,? Phillips said. ?We try not to get attached to the birds, but when you feed them every day, you can?t help but get attached.?

Phillips said members of the park?s staff called the U.S. Department of Agriculture on Sunday after they noticed that Birdzilla, a turkey who had been at the park for nearly 20 years, was displaying possible symptoms of the disease. He said the USDA then came to the park and tested three of its hens, all of which tested positive.

?On Wednesday the USDA came out. We knew what they were going to do, so we got ourselves ready,? Phillips said. ?We didn?t want the public to see, so we put (the birds) behind the barn. I asked for the test results. They were positive.
I couldn?t watch.?

On Thursday, after receiving permission from the Department of Fish and Game, the confiscated wild bird was destroyed.

Phillips said the barnyard portion of the park will be closed to the public until the USDA sanitizes the area Monday.

?I advise anyone who owns birds not to come to the park until the quarantine is lifted,? Phillips said.

Larry Cooper, spokesman for the California Department of Food and Agriculture, said that over the next several days federal officials will go door-to-door to residences in the quarantined area, looking for other infected birds that may need to be destroyed.

?A veterinarian will appraise the bird and the probability that it was exposed to the disease,? Cooper said. ?If the veterinarian classifies it as a dangerous contact bird, it has to be euthanized unless the homeowner requests an appeal.

?People have the right of appeal, but if it is deemed to be infected, those birds are going to die anyway.?

Compensation is available for bird owners who have their birds destroyed by the USDA.

Newcastle disease, which does not affect humans, is a contagious and fatal viral disease that affects the respiratory, nervous and digestive systems of most species of birds. The death rate is nearly 100 percent in unvaccinated birds, and the disease can still infect and kill birds even if they are vaccinated.

Cooper said Newcastle is not a public health threat and does not affect the safety of poultry or eggs, but the disease can be unintentionally transmitted from one bird to another by humans and other animals.

He said owners of any species of bird inside the quarantined area are prohibited from moving their birds or poultry products out of the area without a permit from the USDA. Violators of the quarantine may be subject to fines of up to $25,000.

The discovery at Hart Park was the second known occurrence of the disease in the Santa Clarita Valley. In December the USDA destroyed all of the poultry at the Canyon Country Feed Bin after some of the birds were found to be infected. The owners were compensated, but nonetheless said the incident forced them to shut down permanently on Jan. 31 after nearly 50 years in business.

The last major outbreak of the Newcastle disease was in 1971, when 1,341 infected flocks were found and nearly 12 million birds were destroyed in California. There was also a small outbreak of the disease in 1998.

Then on Oct. 1, the disease was confirmed in the state again. California was then placed under a federal quarantine to restrict the movement of birds to try to stop the spread of the disease.

Since then, 13,207 premises have been quarantined in California, Nevada and Arizona. More than 2,000 of those premises in California contained infected birds and more than 3 million birds have been destroyed. Of those 2,000 sites, 395 were in Los Angeles County.

Cooper said as of February the USDA and the CDFA have spent more than $35 million on an intensive eradication program throughout the state.

He said the state?s quarantine and eradication program will continue until the disease is destroyed.

For more information or to report an outbreak of the Newcastle disease, call the California Department of Food and Agriculture at (800) 491-1899 or go online to www.cdfa.ca.gov.

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