USDA Announces

After retesting, USDA declares "negative" BSE sample as "inconclusive" 

June 10, at 9:00 p.m. eastern time, USDA held a media briefing on BSE. Agriculture Secretary Mike Johanns reminded participants that during the course of the enhanced BSE surveillance program to date, three BSE rapid tests resulted in an inconclusive result. Each of these tests was followed by a confirmatory immunohistochemistry (IHC) test; each IHC was negative. Recently, during an Office of the Inspector General (OIG) audit of the BSE surveillance program, the OIG determined that each of these samples should also be tested using another commonly used test, called Western Blot. While two of these initial inconclusives again confirmed negative using the Western Blot test, one of the retested samples was a reactor, or positive, when the Western Blot was performed.

Since this single sample has conflicting results, the sample will be forwarded to the World Reference Laboratory in Weybridge, England for final confirmation. USDA expects to have protocols for that confirmation developed early next week, but did not comment on when it expects to receive final results from Weybridge.

The sample in question was from an inconclusive announced in November, 2004. The animal did not enter the food or feed chain. USDA has said the animal in question was an older animal and a beef breed. The animal was non-ambulatory when presented for rendering and was condemned and incinerated.

After retesting, USDA declares "negative" BSE sample as "inconclusive" 

June 10, at 9:00 p.m. eastern time, USDA held a media briefing on BSE. Agriculture Secretary Mike Johanns reminded participants that during the course of the enhanced BSE surveillance program to date, three BSE rapid tests resulted in an inconclusive result. Each of these tests was followed by a confirmatory immunohistochemistry (IHC) test; each IHC was negative. Recently, during an Office of the Inspector General (OIG) audit of the BSE surveillance program, the OIG determined that each of these samples should also be tested using another commonly used test, called Western Blot. While two of these initial inconclusives again confirmed negative using the Western Blot test, one of the retested samples was a reactor, or positive, when the Western Blot was performed.

Since this single sample has conflicting results, the sample will be forwarded to the World Reference Laboratory in Weybridge, England for final confirmation. USDA expects to have protocols for that confirmation developed early next week, but did not comment on when it expects to receive final results from Weybridge.

The sample in question was from an inconclusive announced in November, 2004. The animal did not enter the food or feed chain. USDA has said the animal in question was an older animal and a beef breed. The animal was non-ambulatory when presented for rendering and was condemned and incinerated.