Foot and Mouth Strikes Back!

Just when DEFRA was congratulating itself on an apparently successful conclusion to the Pirbright-associated outbreak ( http://www.guardian.co.uk/footandmouth/story/0,,2169045,00.html ), things were thrown into reverse by the identification of foot and mouth infected animals on Milton Park farm near Egham (Surrey) some distance north of the original outbreak. Animals at this and the neighbouring Stroude farm (they also turned out to be positive) have been destroyed (there was an especial focus on pigs at the latter farm as this species is a particularly effective spreader of the virus). The authorities are looking again for evidence that the agent might have been transferred on the wheels of contractor's vehicles from the biosecurity breakdown at the laboratories (the virus is apparently also the same strain as that used at Pirbright). Although the virus has an incubation time in animals of up to 14 days (a factor that is used in terms of specifying the protection and surveillance zones), the virus can survive for up to 50 days in water as well as for long periods in damp contaminated hay. There has been further speculation about sabotage (the movement restrictions could not come at a worse time for farmers as movement restrictions will make it very difficult to take animals to market) and the possibility of the disease having reached (or now reaching) wild animals. The Queen's Great Windsor Park, with its large deer herds (in addition to traditional farm animals), is worryingly within the new surveillance zone, a factor making transmission to the susceptible wild deer more likely. It is also of concern that Heathrow airport and the Ascot horse race course are in close proximity to the current outbreak . Movement restrictions in these localities could also be devastating. The news that some movement restrictions in Wales and areas of England outside the Surrey focus have been lifted so that animals can be taken straight to abattoirs will obviously meet with the approval of hard-pressed farmers but it does slightly increase the risk of the spread of the disease. The decision involves a rather complex balancing of epidemiological, commercial and welfare issues.