Hidden CJD is new threat to thousands

THOUSANDS of people in Britain may be infected with variant CJD, the human equivalent of mad cow disease, without knowing it, research suggests.

Experiments have confirmed that it is possible for a much wider group of people than had been assumed to be infected with the incurable brain condition. The presence in the population of undetected carriers of the infection has serious implications for the safety of the blood supply, and it increases the risk of passing on vCJD to others through infected surgical instruments.

It could make it much harder to eliminate the human infection, even though cattle no longer carry it. Potentially it could linger for generations, or for ever. The team behind the research suggested that their finding represented a “significant public health issue”.

Independent experts said that the work highlighted the need for a national autopsy programme for people who died of causes other than vCJD, to determine the extent of latent infection among those with no symptoms. So far, 161 cases of vCJD have been reported in Britain, 18 in France, and 12 in other parts of the world. These figures are much lower than some early estimates suggested, but the new data indicate that complacency is unjustified.