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Seven labs chosen to test for mad cow

Seven public state laboratories across the nation have been chosen to conduct testing for mad cow disease, the fatal brain disease that first showed up in the United States in December, the U.S. Department of Agriculture said Monday.

The labs are spread out from New York to California and will be responsible for checking samples of cattle brains from all 50 states for bovine spongiform encephalopathy. Currently, that task is handled by a single facility, the USDA's National Veterinary Services Laboratory in Ames, Iowa, which will coordinate national efforts and confirm any initial positives.

The first U.S. mad cow case was discovered Dec. 9 in a dairy cow slaughtered in Washington state. Following that discovery, the USDA announced an expanded testing program. The agency hopes to test as many as 221,000 or more cattle in the next 12-to-18 months as a one time effort to find any additional cases of BSE within the U.S. herd. Last year it tested 20,000 animals.

The seven testing facilities are in Davis, Calif.; Fort Collins, Colo.; Athens, Ga.; Ithaca, N.Y.; College Station, Texas; Pullman, Wash.; and Madison, Wis. All are publicly run by universities and publicly funded, and the USDA will share with the labs some of the $70 million it has allocated for testing.

The agency said that other state labs “that meet specific criteria” may be added as the testing effort ramps up. Ron DeHaven, the USDA’s chief veterinarian, said this month that what the government describes as a “surveillance” program for the disease will be in full force by June.

“We expect that this list will expand,” said Leah Wilkinson, director of food policy for the National Cattlemen’s Beef Association.

Some labs on the list, such as the Colorado facility, already have experience with statewide surveillance for chronic wasting disease, an affliction that infects deer and elk. Both diseases have been traced to deformed prions, or special proteins, that create holes in animal’s brains.

USDA officials in each state will decide how best to collect samples and then send them to the closest lab, a USDA official said. 

Each state will be responsible for a different number of cattle depending on the size of its herd.  Texas and Wisconsin will both be responsible for more than 17,000 samples, according to estimates released last week based on testing of 201,000 cattle, and California will need to test over 24,000 cows. By contrast, Alaska and Rhode Island will be responsible for less than 30 samples apiece.

According to a USDA draft plan, the facilities are expected to be operational by mid-May. Larger labs should be able to test 1,000 samples or more per day. "We are a big state and we do have a lot of cows," said pathologist Sharon Hietala of the California Animal Health and Food Safety Laboratory System, which runs the Davis facility.

Private tests?
Most cows to be tested will be in what the USDA considers “high-risk” categories: those that cannot walk or show signs of nervous system damage, for example.  But it also will test about 20,000 randomly selected healthy cattle, along the lines of a recommendation made last month by a panel of international experts convened by Agriculture Secretary Ann Veneman.

The testing plan, which the government has stressed it considers a one-time endeavor, is “an opportunity to assess the risk of what’s out there and then base the policies on that true risk,” Wilkinson said.

Tests will be performed using rapid screening kits that can return results in as little as four hours.  Beef producers have expressed concerns that the time and extra equipment required to collect samples and process the tests will be an undue burden on them. Under new regulations, carcasses of any cows tested must be held at the slaughterhouse until results come back negative.

"We don’t want to change how they do business by holding samples for a long time while we do testing," Hietala said.

To meet those demands, extra staff and machinery are needed. The Washington Animal Disease Diagnostic Laboratory will hire at least two extra technicians to meet a "very steep" ramp-up timeline, said spokesman Charlie Powell.

The government has approved tests using the Elisa protocol, which destroys normal prions tissue and leaves behind the infectious ones, which are then color stained and detected.  It approved the first such test, by California firm Bio-Rad, 11 days ago. It has since approved a similar test by a Maine company, IDEXX. Both firms previously made tests to detect chronic wasting disease.

The Ames lab will use the rapid tests, but also plans to use a more comprehensive technology known as immunohistochemistry to confirm initial findings.

While it has approved public labs, the USDA has not responded to requests by private labs that also are equipped to conduct the animal tests. Through its congressman, a lab at Wisconsin’s Marshfield Clinic had requested to participate. The Marshfield facility had previously assisted in that state’s CWD tests as well as human disease surveillance.

Government officials have pushed for surveillance of high risk animals, saying that tests of 201,000 will find any single mad cow case among 10 million animals with 95 percent certainty. 

Critics have argued the testing plans fall short, and cannot be used as a guarantee that the U.S. beef supply is safe from BSE. 

Similarly, dozens of trading partners continue to ban the import of U.S. beef, with testing as a major point of contention.  Some appear unswayed by the USDA efforts thus far -- notably Japan, which tests every cow meant to be eaten for BSE.

To address the ongoing bans, DeHaven sent a letter to 75 countries Friday, outlining steps taken by the agency since the discovery of mad cow last December and asking them to consider the U.S. efforts “with a view toward evaluating the appropriateness of any remaining trade restrictions.”

However, the agency has yet to respond to requests by at least one beef processor, Creekstone Farms of Arkansas City, Kan., which petitioned to test every one of its cattle so it could guarantee them free from mad cow disease.  Creekstone’s proposal, which got solid support from Japanese officials, has been viewed with skepticism by larger meat packers and other beef industry representatives.