Scientist demands action to stop `Russian roulette'

RESEARCH

Urgent action to improve the study of the disease pattern of BSE in cattle and Creutzfeldt-Jakob disease in humans is needed, a leading biostatistician said yesterday.

Britain has been playing "Russian roulette with no information on the odds", by allowing beef to be consumed from farms where cases of BSE have occurred, said Sheila Gore, a senior statistician at the Medical Research Council's Biostatistics Unit in Cambridge.

The prevalence of infected cattle by age has not even been monitored by the random examination of cattle brains after slaughter, and any cull strategy must include such studies to establish the prevalence of BSE.

"We must do that, rather than just burn the information," Dr Gore said. That was particularly important, given that more than half the infected cattle reported in 1995 were born after the ban on infected feed was imposed in 1988.

In a leading article in the British Medical Journal, Dr Gore said there is "the strongest case" for random pathology on slaughtered cattle, to establish what proportion are affected at what age and provide projections for the disease in animals.

Much more detailed information about the 10 human cases of CJD - exactly when they occurred and at what age - must be published, to allow the "doubling time" of the epidemic to be established.

The CJD Surveillance Unit, set up in 1990, has fulfilled its remit "spectacularly and speedily" by identifying the 10 cases which led to last week's action, she says.

But the quality of epidemiological data being collected is nowhere near as good as that which Britain established for Aids and HIV. Now that the issue has become a public-health rather than agricultural problem, the "signal failure" to provide good epidemiology must be remedied. That would allow better projections of the risks and the likely course of the two diseases.

Results from a study, which started seven years ago to establish whether dams can pass BSE to their offspring, must be released rapidly and every regulation covering BSE must be reviewed.

The study is being run as a blind trial, with researchers not knowing which calves came from cattle with the disease and which came from cattle which are free of it. Seven years on, it is now time to examine the results, which are crucial for projecting future levels of the disease in cattle, and which have implications for humans.

What, Dr Gore asks, is the evidence for excluding cattle under 30 months from the new de-boning and offal provision, when "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' statements. All evidence must be quantified."