As Britain's latest foot-and-mouth disease outbreak appeared under control and nowhere near as devastating as the last occurrence, in 2001, a government investigation found a "strong probability" that the particular FMD strain involved in this latest outbreak originated at a laboratory complex where the virus is used for research and vaccine production.
The FMD outbreak was confirmed Aug. 3 in cattle on a farm in Surrey, a county in southeast England. Four days later, infections were diagnosed on a nearby farm. By mid-August, fewer than 600 animals had been culled. Several miles of surveillance zones around the outbreak sites were still in place, and restrictions on transporting ruminants were eased after animals at a farm and a theme park tested negative for the virus.
As for the source of the infection, investigators were looking seriously at possible biosecurity breaches at two research facilities in Pirbright, a village in Surrey, operated separately by the government-owned Institute for Animal Health and Merial Animal Health Ltd.
The facilities are located near the farm where the outbreak originated. Moreover, the 01BFS67 FMD viral strain diagnosed at the farm was being used at both facilities July 14-25. The strain was isolated in 1967 and is part of research and commercial FMD vaccine production.
According to a preliminary government report, the Merial site was using 10,000 liters of foot-and-mouth virus in large-scale production, while a series of small-scale experiments were being conducted at the IAH site—less than 10 mL in each case. "(T)he indications are that there is a strong probability that the FMD strain involved in the farm outbreak originated from the IAH or the Merial sites," the report stated.
It seemed unlikely that the virus was released through the air, the report continued. The possibility that the animals were infected by tainted water from the research complex, while remote, had not been ruled out. Investigators did say human movement of the virus, whether accidental or intentional, was "a real possibility."
In separate statements, the Institute for Animal Health and Merial said they were cooperating fully with the investigation.
More than 6 million animals were culled during Britain's 2001 FMD outbreak, resulting in billions of dollars in lost agriculture and tourism as movement throughout the country was restricted. News of the recent outbreak caused U.S. and European Union markets to close to British meat and dairy exports. The European Union had lifted most restrictions by late August, but the U.S. ban remained in place.
Governments are reluctant to vaccinate animals against the FMD virus for various reasons, such as potential impacts on export trade.
Still, the British government would not rule out vaccination if the outbreak were to become widespread. "The decision not to vaccinate at this stage, but to retain our full readiness to do so, demonstrates that our contingency planning arrangements are working," said Dr. Debby Reynolds, Britain's chief veterinary officer.