Until now it has only been possible to diagnose cases of new variant CJD, the disease linked to BSE in cattle, after death. The test involves taking tissue from the tonsils and can be conducted on living people. The findings could eventually mean scientists will be able to develop a test which could diagnose people with nvCJD as soon as they are infected. But the findings also raise concern about infection caused by the rogue proteins that spread the disease and cannot be cleaned from surgical instruments no matter how thoroughly they are sterilised. Writing in The Lancet, the scientists led by Professor John Collinge at the Imperial College School of Medicine at St Mary's Hospital in London, say they tested tonsil tissue from 20 patients in the late stages of suspected prion disease.
Prions reproduce in the tissues of the immune system, including the tonsils.
Because of the theoretical possibility that the disease could be spread by surgery to the infected organs Professor Collinge recommends that for such operations only disposable surgical instruments be used. The infection can withstand high temperatures which make the usual sterilisation procedures ineffective. Dr Stephen Dealer, from the BSE Research Campaign, said the findings would help to assess the risk from surgical instruments. This is one of the reasons why John Collinge's test may be so wonderful. It will give use some insight into just how big that risk is.