Search for disease source widens

The virus can be carried on the boots of drivers

As many as 600 farms could be placed under investigation in the race to trace the source of the outbreak of foot-and-mouth disease.

The search is being widened to take account of the distances the virus might be carried by the wind and the volume of lorry traffic to and from the Essex abattoir where the highly infectious disease was detected, a Ministry of Agriculture spokesman said.

"We're tracing the movement of the vehicles that brought the pigs in to try and trace the origin of the disease as quickly as we can," Sam Harrison told BBC News Online

The virus can be passed from farm to farm through the air or carried on lorries and on the boots of drivers.

We are now all exposed to imports of food by the directly formal imports or indirectly from people coming in and bringing food with them without the checks on them that there used to be and in quantities we have not experienced

National Farmers' Union chairman, Ben Gill

Agriculture Minister Nick Brown said earlier: "We need to trace every single movement into the abattoir where this was discovered, to check every farm and if there's any suspicion that there is foot-and-mouth present, the farm has to be quarantined."

The disease has been identified as "type O" strain, with tests suggesting it is similar to that which caused outbreaks in Japan, Korea, Mongolia and Russia.

Officials have said none of the infected animals had been imported into Britain.

But that does not rule out the origins of the infection from illegal foreign meat contained in the pig rations.

Another possible cause is an infected meat product from abroad being carelessly discarded and eaten by pigs - the suspected source of the recent swine fever outbreak.

But National Farmers' Union chairman Ben Gill has claimed that international trade may be to blame for the current crisis.

"We have to look at this and ask some more questions," he told the BBC's Today Programme.

Asian origin

"Is it a coincidence that we had classical swine fever in East Anglia last year of an Asian origin and here we now have foot-and-mouth in East Anglia again of an Asian origin - why is that happening?

"It does raise questions about this increasing wish to freer world trade.

"We are now all exposed to imports of food by the directly formal imports or, indirectly, from people coming in and bringing food with them without the checks on them that there used to be and in quantities we have not experienced.

"We have to consider whether this is wise and whether we ought to be looking much more to our home production for the security that we need."