Mike
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BSE Alert: 2 Preliminary Tests Now Show Possible New Case
WASHINGTON (Dow Jones)--Two preliminary tests - one done in a state laboratory on Friday and one at a federal facility on Saturday - both show a possible new U.S. mad-cow disease infection, a U.S. Department of Agriculture spokesman said Sunday.
The USDA made the decision to publicly announce what it calls an "inconclusive" result after a first preliminary test showed the possibility of mad-cow disease, or bovine spongiform encephalopathy. The results of that test came in Friday and the USDA disseminated the information to reporters by Saturday evening, but while that was happening federal scientists at USDA's National Veterinary Services Laboratories in Ames, Iowa, performed a second preliminary test, spokesman Jim Rogers said Sunday.
That second rapid test also showed a possible BSE infection and scientists in Ames began immediately conducting two separate "confirmatory" tests, USDA's Rogers said. Results are expected from those confirmatory tests in four to seven days and if either one produces a positive, the USDA will declare it the third official case of BSE found in the U.S.
There are different levels of BSE indication on the thousands of preliminary "rapid" tests scientists do across the country to monitor herds. The USDA does not publish a "one-well" result, but instead waits until two or three "wells," or indicators, are present in the rapid test. In this case, both preliminary tests produced either a two- or three-well result, Rogers said.
The last time that happened, USDA later confirmed finding its second case of BSE in the U.S.
Saturday, after the first preliminary test was relayed to USDA headquarters in Washington D.C., USDA Chief Veterinary Medical Officer John Clifford said: "This inconclusive result does not mean we have found a new case of BSE. Inconclusive results are a normal component of most screening tests, which are designed to be extremely sensitive so they will detect any sample that could possibly be positive."
USDA scientists in Ames are conducting confirmatory immunohistochemistry and Western blot tests. Doubts were raised about the effectiveness of the immunohistochemistry test when it failed to detect BSE in November 2004.
After that misdiagnosis, revealed about six months later in June 2005 by subsequent testing, USDA announced new policy to add the Western blot test as a second confirmatory measure to be performed along with the immunohistochemistry test.
That second BSE case was confirmed in a Texas-born cow. The first case of BSE ever confirmed in the U.S. by USDA was found in December 2003 in Washington state, but the animal was later revealed to have been born and likely infected in Canada before being shipped to the U.S.
USDA has not disclosed the origin of the cow now being tested.
USDA began what it calls its "enhanced BSE surveillance program" in June 2004 in response to the first BSE case and has since tested more than 640,000 cattle.
WASHINGTON (Dow Jones)--Two preliminary tests - one done in a state laboratory on Friday and one at a federal facility on Saturday - both show a possible new U.S. mad-cow disease infection, a U.S. Department of Agriculture spokesman said Sunday.
The USDA made the decision to publicly announce what it calls an "inconclusive" result after a first preliminary test showed the possibility of mad-cow disease, or bovine spongiform encephalopathy. The results of that test came in Friday and the USDA disseminated the information to reporters by Saturday evening, but while that was happening federal scientists at USDA's National Veterinary Services Laboratories in Ames, Iowa, performed a second preliminary test, spokesman Jim Rogers said Sunday.
That second rapid test also showed a possible BSE infection and scientists in Ames began immediately conducting two separate "confirmatory" tests, USDA's Rogers said. Results are expected from those confirmatory tests in four to seven days and if either one produces a positive, the USDA will declare it the third official case of BSE found in the U.S.
There are different levels of BSE indication on the thousands of preliminary "rapid" tests scientists do across the country to monitor herds. The USDA does not publish a "one-well" result, but instead waits until two or three "wells," or indicators, are present in the rapid test. In this case, both preliminary tests produced either a two- or three-well result, Rogers said.
The last time that happened, USDA later confirmed finding its second case of BSE in the U.S.
Saturday, after the first preliminary test was relayed to USDA headquarters in Washington D.C., USDA Chief Veterinary Medical Officer John Clifford said: "This inconclusive result does not mean we have found a new case of BSE. Inconclusive results are a normal component of most screening tests, which are designed to be extremely sensitive so they will detect any sample that could possibly be positive."
USDA scientists in Ames are conducting confirmatory immunohistochemistry and Western blot tests. Doubts were raised about the effectiveness of the immunohistochemistry test when it failed to detect BSE in November 2004.
After that misdiagnosis, revealed about six months later in June 2005 by subsequent testing, USDA announced new policy to add the Western blot test as a second confirmatory measure to be performed along with the immunohistochemistry test.
That second BSE case was confirmed in a Texas-born cow. The first case of BSE ever confirmed in the U.S. by USDA was found in December 2003 in Washington state, but the animal was later revealed to have been born and likely infected in Canada before being shipped to the U.S.
USDA has not disclosed the origin of the cow now being tested.
USDA began what it calls its "enhanced BSE surveillance program" in June 2004 in response to the first BSE case and has since tested more than 640,000 cattle.
