British authorities hunting the source of an outbreak of infectious foot and mouth disease focused their investigation yesterday on two research labs located just kilometers from where a herd of cattle was infected.
While there was no confirmation the research sites were the source of the infection, both high-security labs -- one run by the government's Institute for Animal Health and the other by a pharmaceutical company called Merial -- were sealed off and placed within a 10km exclusion zone.
Both laboratories handle a variety of strains of foot and mouth, conducting research into the virus and developing vaccines against it, and other animal diseases.
But Member of Parliament Hilary Benn said it was too early to say whether the site of the two labs -- known as the Pirbright facility -- was definitely the source of the virus, which was found to have infected a herd of about 60 cattle at a farm 5km away.
"This is a promising lead but we do not know for sure," Benn, who cut short his family holiday in Italy to return to Britain when the outbreak was confirmed late on Friday, told BBC News 24 television.
"That's why we are being prudent and while we are doing this work it's very, very important that people continue to be observant, that farmers look at their stock and if they have any suspicions they report them as quickly as possible," he said.
Merial, one of the world's leading animal health firms with sales last year of US$2.2 billion, is jointly owned by US drugmaker Merck & Co and France's Sanofi-Aventis SA.
Attention focused on the labs as the possible source of the infection after Defra, Britain's department for agriculture, said the strain of foot and mouth confirmed in 60 head of cattle on Friday was not one recently found in animals.
In fact, it was a strain of the virus isolated nearly 40 years ago by British biological researchers, it said.
The UK's chief veterinarian, Debby Reynolds, ordered an "urgent review into biosecurity arrangements" at both sites, although Defra also emphasized that "all potential sources" of the virus were still being investigated.
The infected animals, found on a farm in Surrey, southwest of London, were isolated, culled and taken away for burial on Saturday. A nearby herd was also culled as a precaution.
"The foot and mouth strain found in Surrey is not one currently known to be recently found in animals," the agriculture department said in a statement.
"It is most similar to strains used in international diagnostic laboratories and in vaccine production," it said.
"The present indications are that this strain is a 01 BFS67-like virus, isolated in the 1967 foot and mouth disease outbreak in Great Britain.
"Immediate action is being taken with an investigation led by the Health and Safety Executive at the Institute for Animal Health and Merial."
If it is found that the cattle were infected by a leak from the Pirbright laboratories, it may reassure Britain's farming community, still reeling from a devastating food and mouth outbreak in 2001, that the disease can be isolated.
However, it will cause consternation in the scientific community that a highly infectious pathogen, carried on the wind, can escape from a high-security laboratory.
The latest outbreak comes six years after a foot and mouth crisis that devastated British farming, with more than 6 million animals culled and countrywide tourism affected, at a total cost estimated at ?8.5 billion (US$17 billion).