SCIENTISTS WHO analysed the spread of Foot and Mouth Disease in Britain this year have concluded that the size and duration of an epidemic is highly sensitive to any action taken in the first few days of an outbreak. Researchers from the Universities of Edinburgh, Cambridge and Guelph in Ontario, Canada (working with the Veterinary Laboratories Agency) also suggest that the Government’s culling programme has been extremely effective in restricting the spread of the epidemic.

But the scientists, who also assessed several alternative vaccination strategies, found that inoculation would not have been as effective.

The ten researchers, three of whom sit on the Government’s advisory committee on the control of infectious diseases, have carried out the most comprehensive analysis to date of the epidemic. Although the dynamics of the disease are complicated and very often down to chance, the scientists claim to have built up an accurate picture of its spread, thanks to data collected by the Department of the Environment from every farm in the UK. The findings, which have allowed the researchers to draw “a number of robust qualitative conclusions”, have just been published in the US journal Science.

Professor Mark Woolhouse, of the University of Edinburgh’s Centre for Tropical Medicine, said: “The course which the epidemic has taken has been determined by a combination of frequent local spreading of the disease and occasional long range jumps which have occurred in a variety of livestock farms. Having a knowledge of the distribution of farms, their sizes and compositions is crucial to explaining the falling number of cases in April and the subsequent prolonged epidemic.

Essential

“Our analysis also confirms that the culling policy introduced in late March was essential to bring the disease under control. Modelling the impact of various vaccination programmes show these to be less effective than culling and possibly insufficient to bring the disease under control. The key to reducing the size of an epidemic of this kind is rapid intervention: earlier implementation of movement restrictions and of the culling policy would have greatly reduced the number of cases and the total number of livestock killed.”