Despite the reservations of some British scientists, the Super Valu supermarket group has defended its use of a test developed by an Irish research company said to prove that beef on sale in its outlets is BSE-free.
The Irish-owned group dismissed criticism of the Enfer BSE test by scientists, who claimed there was no evidence it can detect BSE in carcasses of infected animals which have not yet developed symptoms of the disease.
A Super Valu spokesman said that since last month, when it introduced the test on beef sold at its outlets, it had led to increased sales. It sells about £25 million worth of Irish beef a year.
Enfer's technical director, Mr Michael O'Connor, said there was no question mark whatsoever over the test. "All the research has shown that the Enfer test will detect BSE in all beef."
The Super Valu spokesman said the group was happy "that an extra level of protection and assurance" is provided for its customers by using the test, the only independent test available to show meat is BSE-free. A prerequisite for its use had been that it had to be independently validated by a competent authority, which had been done. In addition, it went beyond "traceability" by ensuring the safety of every single carcass.
When Super Valu adopted the test, the news was featured prominently in the British press - including the front page of the Financial Times - while shares in the research company Proteus International, which was involved in developing an antibody used in the test, rose sharply. A number of prominent British research companies are attempting to develop similar tests.
The post-mortem test detects a specific prion protein (PrP) present only in BSE-infected central nervous tissue. It was validated by the Department of Agriculture's Veterinary Research Laboratory and considered "an excellent diagnostic test for BSE".
Some British scientists have, however, expressed concern that the antibody used cannot identify BSE-infected animals which have yet to exhibit any symptoms of the disease. "This test may be acceptable commercially but it is not acceptable scientifically," alleged Mr Roy Jackman, an antibody specialist at the British Central Veterinary Laboratory in Surrey.
A number have dismissed the methodology on the basis that it has not featured yet in scientific literature. But a confidentiality clause prohibits the Irish authorities releasing exact details of the validation until Enfer has secured a patent.
Irish veterinary authorities have confirmed that the test was not validated using tissue samples from infected animals showing no signs of BSE. But Mr O'Connor told British Farmers Weekly last week: "We're just saying here's a test that measures the real thing; the infective agent. The whole thing about clinical versus subclinical is another discussion."
New Scientist magazine has quoted BSE experts who said that knowing the stage of infection at which a test can identify an animal that will succumb to BSE is crucial. Animals with symptoms must be excluded from the food chain in any event.
