Model targets foot-and-mouth risk

UK scientists have found a way to quickly identify livestock at risk from infection through airborne transmission of the foot-and-mouth virus.

The control of foot-and-mouth outbreaks is of global socio-economic importance.

Researchers have created a simple risk model by combining weather and livestock information collected during the 1967 UK foot-and-mouth outbreak.

It may be possible to automate the system, the scientists suggest in the Journal of the Royal Society.

Outbreaks of foot-and-mouth - a highly contagious disease of cloven-hoofed animals - cause severe disruption to the farming sector and economy.

Dr Schley from the Pirbright Laboratory at the Institute for Animal Health in Surrey explained that transmission of the virus between different premises can mostly be controlled by implementing stringent control measures:

"You can stop animal movements, try to enforce bio-security on farms and try and make sure people disinfect themselves," he told BBC News.

However, airborne transmissions are particularly difficult to control: "All we can do is try to detect and contain such transmissions afterwards," explained Dr Schley.

Airborne transmission of virus particles is influenced by the wind and atmospheric turbulence.

Dr David Schley and colleagues used NAME in their study - a system that has been developed by the UK Meteorological Office to predict the weather.

They also incorporated details about the source of the virus - including the number of animals infected.

The model was tested by applying it to the recent 2007 UK outbreak in Surrey.

Data deficient

The scientists recognise that successful implementation of these predictions requires accurate information regarding the location of animals before any outbreak occurs.

The independent review of the 2007 UK foot-and-mouth outbreak by Dr Iain Anderson included recommendations for improved "data and information management systems".

"(Currently), we know where the owner of the animals lives, but that is slightly different from knowing where the animal is. If that information was available you could make some useful and powerful predictions in terms of risk," said Dr Schley.

He added: "The level of information that I would like the UK to aspire to has already been achieved by other countries - including New Zealand."

A well-coordinated and reliable data system could be automated: "The next day (we) would be able to say, these are the farms that we feel are the priority for inspection."

Scientists at the Institute for Animal Health have developed other models for predicting the transmission of other viral diseases that affect livestock:

"(Bluetongue) is spread by midges - but they can be affected by which way the wind blows because they are so tiny and light," commented Dr Schley.

RELATED INTERNET LINKS
Foot and Mouth review, 2007
Institute for Animal Health, Surrey
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