(Updated 6/5/01)

Foot and Mouth: how modern science cracked the virus


by Nick Mays

THREE WEEKS ago Professor David King of the Office of Science and Technology made the long-awaited announcement that the Foot and Mouth epidemic is now officially under control.

A cynical public, wearied by daily images on the TV screens of slaughtered cattle, sheep and pigs lying to rot for days on end, or smoking funeral pyres of those carcasses which have been burnt, or tearful farmers, their livelihoods ruined, may well have dismissed Professor King’s statement as more political wishful thinking.

After all, hadn’t Agriculture Minister Nick Brown been saying for weeks that the outbreak was “under control”? It quite patently was not and nobody was fooled.

However, the difference between Professor King’s statement and that of Mr Brown is that Professor King’s statement is based on hard scientific fact and has subsequently been proved to be correct, the number of FMD cases IS slowing down.

Professor King is part of dedicated team of 70 scientists based at Imperial College led by Professor Roy Anderson. The Imperial team have been working 20-hour days from their base in London, close to St Mary’s Hospital, Paddington, using computer models and data gathered by ‘shoe leather’ epidemiologists throughout the country on the daily rate of reported cases.

Widespread

Politicians and MAFF have learnt many lessons since the outbreak was first officially announced in February. The team found “serious warning signals” in the data they were receiving that the outbreak was far worse and more widespread than MAFF had first believed.

Had the team’s warnings been heeded, better control measures could have been put in place. Team statistician Chris Donnelly had published a series of post mortems on earlier FMD outbreaks and was disturbed by what she found. Her paper in Research in veterinary Science came to an unequivocal conclusion: to have any chance of controlling an epidemic, infected animals must be slaughtered on the day of diagnosis.

On March 14th, three weeks into the outbreak, MAFF provided the Imperial team with data on the delay between report to confirmation, and confirmation to slaughter. The following day the Imperial team told MAFF a chilling story: each outbreak was generating an average or more than one subsequent outbreak. By March 16, a week after the scheduled Crufts show, MAFF knew the epidemic was out of control.

A crisis meeting was held between the Imperial Team and key Government departments. On March 21st Professor Roy Anderson went public on BBC news that the outbreak was out of control. On March 23rd, the question of inadequate resources was brushed aside by Government. The army were drafted in, as many slaughtermen and vets as possible were brought in and Prof King’s target of 24-hours-to-slaughter, as well as 48 hours to slaughter of livestock on surrounding farms was implemented.

Two weeks ago, the Imperial Team’s prediction - based on computer models using the stated policy - was proved to be true; the number of reported FMD cases began to drop. Pride Professor King went on record as saying: “I believe the policy is beginning to bite. Praising the data gathered by MAFF and the vets and the “fantastic science base” that he could draw on to fight the epidemic. The match of predictions to data was “a remarkable example of the power of these methods” according to Prof King. But as to whether the slow down of FMD would continue was, according to Prof King, dependant entirely in “what happens on the ground.”

Professor Roy Anderson, meanwhile, displaying justified pride in his team’s efforts, warned against complacency. “It is far too early to be totally optimistic. The crunch problem is that it is vital the farming community stick by this policy rigorously. If there is a relaxation, there will be resurgence. That would be a disaster.”