BSE retest positive; criticism rampant

Cattle Market & Farm Reports, Editorials
Jun 20, 2007
by WLJ
20, 2005

— UK test results expected late June.
— Testing protocol breach suggested.

A sample of brain matter from a “downer” cow collected last November was retested for BSE earlier this month and came back positive for the brain-wasting malady.
Officials with USDA’s Animal and Plant Health Inspection Service (APHIS) were awaiting confirmatory testing from a British lab to determine if the animal was indeed infected with the disease.
Producer groups last week were very critical of USDA’s announcement concerning the BSE test, saying that surveillance protocol was breached when an announcement was made prior to final test results being received from Great Britain.
On June 10, USDA Secretary Mike Johanns and USDA chief veterinarian Dr. John Clifford said the agency’s Office of Inspector General (OIG) requested earlier that week that three beef samples previously determined to be negative for bovine spongiform encephalopathy, but showing “preliminary inconclusive” results after a rapid test, be reassessed using a different type of test. One of those three retested samples came back positive, and efforts were being made last week to get that sample shipped to Britain where the final test would be conducted.
Preliminary inconclusive means that the original rapid test came back with a positive result. However, a confirmatory immunohistochemistry test on all three preliminary inconclusive test samples from last year showed the disease did not exist in those animals.
OIG came back to USDA early in the week of June 6 and requested that APHIS scientists retest the three preliminary inconclusive samples with a different test, called the “Western blot.” USDA officials said that past assessment of both the IHC and Western blot tests have shown them to be equal in their accuracy and effectiveness in determining presence of BSE. Why OIG made the request was not disclosed by USDA or APHIS officials.
“OIG, which has been partnering with APHIS, the Food Safety and Inspection Service, and the Agricultural Research Service by impartially reviewing BSE-related activities and making recommendations for improvement, recommended that all three of these samples be subjected to a second internationally recognized confirmatory test....Of the three samples, two were negative, but the third came back reactive,” said Dr. John Clifford, chief veterinarian for USDA.
He added that the animal in question was a 10-12 year old “downer” cow, that did not meet criteria for being processed into human food or animal feed. The animal also was born prior to the 1997 feed ban restricting use of ruminant meat-and-bone-meal (MBM), which means the animal could have received feed contaminated with the agent responsible for BSE.
“Regardless of the outcome (of the confirmatory test in Great Britain), it is critical to note that USDA has in place a sound system of interlocking safeguards to protect human and animal health from BSE, including a ban on specified risk materials from the human food supply,” Clifford said. “In the case of this animal, it was a non-ambulatory animal and as such was banned from the food supply. It was processed at a facility that handles only animals unsuitable for human consumption, and the carcass was incinerated.”
Criticism launched at USDA
Futures and cash cattle markets last week were both directly impacted by USDA’s decision to announce the Western blot test results, and producer organizations were upset because USDA went against normal protocol to wait to announce any results until final tests are completed.
In a letter to U.S. Agriculture Secretary Mike Johanns, Jim McAdams, president of the National Cattlemen’s Beef Association (NCBA), said, “We expect a full explanation of the circumstances that caused OIG to recommend additional testing of previously identified BSE negative animals. While NCBA has supported the surveillance program and its intent, these most recent actions by USDA and the OIG do not increase the safety of U.S. beef, nor do they improve the health of the U.S. cowherd, but instead put the industry at greater economic risk.
“We call upon USDA to clearly communicate the scientific basis for the protocol that they will follow, and the time frame that the industry can expect to bring this current issue to resolution. It is important not to communicate the results of this situation until they are definitive. To prevent further economic uncertainty in the market, USDA should not release intermediate test results or additional information that is not final and conclusive in nature.”
State and regional producer groups had additional concerns about USDA’s recent actions, including the following questions:
• Why did USDA not announce the change in surveillance protocol prior to accepting OIG’s recommendation to retest using the Western Blot test?
• Is the IHC test still considered the “gold standard,” and why was the extra Western blot test not done last November?
• Why was the suspect sample “enhanced” to complete the test? According to the Nebraska Cattlemen Inc. perception is that the sample was concentrated last November to achieve a “weak positive.”
• How is USDA preparing for a confirmed positive or a negative test result from the Weybridge, England, laboratory?
USDA officials said they would not give any more details on the situation until final test results were received from the British laboratory. Those results are expected to be known right around the end of the month. APHIS scientists said it would take at least two weeks from June 10, before results would be known. — Steven D. Vetter, WLJ Editor

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