Scientists Shocked As
CJD/Mad Cow Disease
Reveals New, Deadly Traits
By Robert Matthews
The growing concern over the health of the baby born to a mother with variant CJD and the new evidence, announced last week, that the disease may have spread through blood transfusions, highlight the disturbing ability of vCJD to surprise the experts.
A conclusive diagnosis of vCJD in the 11-month-old child would imply a far shorter incubation period than many scientists thought possible. It would also mean that the disease can be passed down the generations, not merely acquired through contact with infected tissue.
Scientists have yet to pin down the likely size of the vCJD epidemic, with estimates for Britain ranging from about 100 cases to more than 100,000; so far there have been only 82 probable or confirmed cases. The case of the baby girl means that scientists are now admitting that many predictions may have to be rethought.
According to Dr Neil Ferguson of the University of Oxford, a leading expert on the mathematics of epidemics, so-called vertical transmission down the generations has, at least until now, been thought to be relatively unimportant.
Dr Ferguson said: "It very much depends on the probability of it taking place. If a woman has to be very sick and symptomatic in order to give it to her baby, then the number of cases it creates are going to be very small, because she is unlikely to get pregnant."
The mother of the baby at the centre of the current concern is, however, understood to have been showing only minor symptoms of the disease at the time of conception; only later in her pregnancy did she develop the classic symptoms of vCJD from which she died in May this year.
Richard Lacey, an emeritus professor of medical microbiology at Leeds University, said that the Telegraph story had wider implications than its obvious medical significance. Prof Lacey said: "The only thing that is certain is the scale on which it is happening. That will take decades to find out. I am aware of other cases where maternal transmission could be an issue; this isn't the only one.
"This poses difficult ethical problems: to what extent should individuals be told of the risk? Should such a person be told not to give blood when he or she is old enough to do so? What effect will this knowledge have on that person's way of life, on their emotions? There needs to be some sort of discussion about how we cope with it, but at the moment there is nothing."
Epidemiologists are puzzled by the fact that vCJD is predominantly affecting young people, while classic CJD is a disease of the old. Prof Lacey suggested that one possible explanation is that the teenagers and young people who have died from vCJD may have contracted the disease from their mothers while in the womb. He added that it is a recognised clinical syndrome that infectivity accumulates when it is passed on from one generation to the next.
Dr Stephen Dealler, an expert on BSE and vCJD at Burnley Hospital, said that it had been believed that mother-to-offspring infection could take place in cows, but only with a considerable incubation period. "The thinking is that it may take place in cows, but the incubation period is still three to five years," he said. "This would lead us to expect an incubation period of around seven years in humans. If the baby does have vCJD, that's a very fast incubation period."
Last week's revelation resulting from animal experiments that the disease may be transferred through blood transfusions from infected people with no symptoms was being played down by government scientists, who said that all British blood is screened to remove cells that may harbour vCJD.
The Telegraph has learnt, however, that the Department of Health is seriously considering the use of disposable surgical instruments throughout the National Health Service. This follows growing concern that blood and tissue from asymptomatic carriers of the disease could remain infectious even after sterilisations.

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