BSE odds are unknown

Kam Patel reports on accusations of 'woefully inadequate' statistics on BSE, and the launch of a new research programme. A senior statistician accused the Government this week of playing "Russian roulette" with statistics on bovine spongiform encephalopathy (BSE).

Sheila Gore, based at the Medical Research Council's biostatistics unit in Cambridge, says that data collection and safety regulations relating to BSE are woefully inadequate.

In an article in the British Medical Journal today Dr Gore urges the immediate introduction of random testing of slaughtered cattle to see how many are infected. She also wants victims of Creutzfeldt-Jakob Disease and their children monitored to gauge the risk of transmitting the disease from mother to child.

Last week the Government announced that ten people infected with a previously unrecognised variant of CJD had been identified. The Government's Spongiform Encephalopathy Advisory Committee said the most likely explanation of this new form of CJD in humans is exposure to BSE before the introduction of the specified offal ban in 1989.

Dr Gore says that the ten new cases were referred to authorities in a period of less than six years. "If in the past six months the number of cases increased from five to ten, a further increase from ten to 20 cases in the next six months would be consistent with an epidemic; but, because of chance, so too would any number of cases from four to 16," she says.

Dr Gore also urges the monitoring of health workers exposed to patients with CJD, and workers who have dealt with cows suspected of having BSE.

She says that in sharp contrast to the study of HIV and Aids in humans, projections about the prevalence of BSE have been subjected "to neither deliberation by independent working party nor to statistical peer review".

And Dr Gore points out that even with HIV/Aids mistakes were made in the early days: the lack of evidence of HIV transmission via breast milk for example was found to be a false assurance. Initial guidelines drawn up for HIV-infected healthcare workers were inadequate: "Such mistakes are likely to be repeated in dealing with BSE," she says.

Dr Gore asks what evidence SEAC has for excluding cattle under 30 months from the new deboning and offal removal provisions announced last week.

"Some bovines under 30 months are certainly infected. Let us have done with misleading the profession, the public and the press with unqualified 'no evidence of' statements," she adds.

She says that even before the recent moves to ban British beef the European Union was not happy with relying on just standard qualitative measures of infectivity for reassurance on the safety of beef.

Brussels restricted imports to bovines born after the British Government issued a bovine offals ban in 1989 and to farms that had not had a recent case of BSE.

Dr Gore says: "No such restriction limited British consumption. Practically we do not have in vivo or in vitro tests for infected cattle and so have continued to play Russian roulette with no information on the odds."