Less than a decade ago, a ghastly vision of disease and death was played out, night after night, on our television screens. In front of us were distressed cattle, suffering from bovine spongiform encephalopathy (BSE), their bodies bereft of any co-ordination as they slipped and scraped their way around their pens, awaiting slaughter.
A worse blow would follow. We learnt that scientists had discovered that “mad cow disease” was able to jump the species barrier. A new variant of a rare brain-wasting disorder, Creutzfeldt-Jakob disease (CJD), had been identified, identical pathologically to BSE. Unlike CJD, the new variant did not predominantly afflict elderly people — it struck at the under 40s, including teenagers.
It seemed time was up for our fast-food culture, driven by the pursuit of cost-effective slaughterhouse practices. The most pessimistic estimates of the effects of the new disease suggested that up to a million people might die.
It hasn’t turned out like that. So far 150 people have died from vCJD, with a further five known to be living with it. Each casualty of course is a devastating tragedy for the family involved, as once healthy people are ravaged by a condition that strips them of their memory, their ability to walk, speak and ultimately their capacity to feed themselves. But a catastrophe of biblical proportions has not descended.
Tucked away in his office, deep in Edinburgh’s Western General hospital, Dr Richard Knight is drinking coffee, and discussing the impact of those predictions. Knight is the new director of the National CJD Surveillance Unit, but with his long hair and laid-back manner, he looks more like a man with a passion for motorbikes than one of Britain’s leading scientists.
Knight, 54, a consultant neurologist, has the difficult job of monitoring the spread of the disease and understanding its epidemiology.
But he also has to answer those sceptics who can point to other more recent phantom epidemics, like Sars in 2003 and this year’s Asian bird flu scare. Both have been killers in the Far East but, so far at least the casualty figures in Britain and Europe have been all but nonexistent.
For Knight, making sense of contradictory figures is possible only if hyperbole is replaced with statistical evidence and scientific fact.
“The early predictions for vCJD were certainly on a hiding to nothing,” he says, attributing the “somewhat excessive” figures to the limited data available in the mid-1990s. “Our current understanding and belief is that there are not going to be tens of thousands of people dying from vCJD.” Instead he believes the figure is likely to be several hundred.
Part of the problem, he believes, lay in the media, where too many commentators were keen to seize on the worst-case scenario to make a good headline. “There were certain individuals at the time who were making very extravagant predictions and some of these were not scientifically based,” he says.
“They were in a sense voicing fears, but that sort of thing is not what I would call a scientific prediction. What I mean by scientific predictions are the people who have done a careful analysis of the figures and published them in peer review journals. Some of these predictions said there might be 80 cases or there might of tens of thousands, and it was couched in rather statistical terms.”
On reflection he says: “I don’t think that is denting public confidence. But it is unfortunately an example of the innumeracy of the population in general. Scientists can’t be blamed for that. If they publish something in a peer-review journal in scientific language and if somebody doesn’t understand that and misquotes it is not their fault.”
Knight spends half his working time at the Western General treating patients with a range of neurological conditions, from multiple sclerosis and Parkinson’s disease to migraine and epilepsy. The rest of his schedule is dedicated to the CJD monitoring unit, which was first established in May 1990 in response to concerns about BSE. At that time it was run out of a temporary office with a handful of staff. Its job then was to identify any change in the pattern of CJD which might be attributable to BSE. Now Knight leads a team of about 45 people in a purpose- built building, its brief to lay bare the truth about this complex disease.
Within the unit there is a range of projects, some trying to prove the link between diet and the disease, others devising tests to diagnose the condition. Thanks to Knight and his predecessors, more is known about the genetic predisposition to the disease, which helps explain why one person contracts vCJD and another with an identical diet does not.
With every suspected case of vCJD, Knight’s team swings into action, meticulously tracking down its cause. So far deaths have occurred in people of a specific genetic type, known as MM, which is shared by a third of the population — a pattern which the unit is trying to explain. Most of the victims are young. The average age at death is 28, though the range is 12 to 74.
There are other oddities. There has been, for example, a cluster of five cases linked to the small Leicestershire village of Queniborough. After exhaustive research, this anomaly appears to have been caused by butchering practices, although with his eye on statistics, Knight points out that it could be simply chance. “Rare events do happen,” he says.
With time and more cases to work on comes greater understanding, and Knight believes, more accurate assessments of the real risk posed to the general public.
Changes in the food and farming industry should mean our food is now completely safe. However, the long and uncertain incubation period — which is believed to be up to 30 years — means Knight is decades off announcing the end of the threat. However, the evidence is telling him that this first wave of the disease is likely to have been the worst. “The absolute risk is minimal,” he says.
Knight remains unhappy with the public’s understanding of the work of scientists, and the capacity of the media to swing from alarmist predictions to withering cynicism.
He says: “We live in an age where there is an increasing gap between the amazing progress of science and what seems to be an increasingly appalling ignorance of the whole method and philosophy of science in the general population. That is very worrying.”
Most alarming of all, perhaps, for the rest of us, is this meticulous scientist’s opinion on the latest health scare.
“All the scientists and other people I have heard talking about bird flu seem to regard some form of epidemic as actually extremely likely,” he says calmly. “That is certainly very worrying.”
