UK virus outbreak likely due to Surrey labs

The foot-and-mouth disease (FMD) outbreak identified in cattle on a farm in Surrey, UK, last week most likely originated from virus research and vaccine production labs nearby, according to a government investigation.

According to the government's report, released on August 7 by the Health and Safety Executive, the virus may have escaped from Pirbright Labs in Surrey via the facility's water system, or been accidentally carried by people entering and leaving the building. Pirbright houses two separate facilities, the Institute for Animal Health (IAH) and the pharmaceutical company Merial Animal Health Ltd., that research and produce vaccines for FMD. One possibility, the report said, is that heavy rains could have overwhelmed the facility's drainage system, somehow allowing the virus to escape.

"To us, [the report] is still inconclusive," Steve Dickinson, spokesperson for Merial, told The Scientist. He added that Merial is confident in its biosecurity measures. "We're continuing to cooperate with the investigation," he said.

The outbreak was confirmed Friday, and since then, researchers have been working to identify the source of the outbreak strain. On Sunday, researchers with the IAH identified the virus strain as "very close" to 01/BFS67, a strain originally isolated in 1967, which was not known to be in circulation but was housed at both facilities. DEFRA has ordered the cull of 214 animals so far to stop the spread of the virus.

"I think the report makes it quite obvious that this particular virus has come from the labs," said Philip Duffus at the University of Bristol in North Somerset, England. "They both had very good biosecurity" he said, but it is "quite ironic" that their work has led to this outbreak.

He added that if the virus was transmitted through water, it most likely affected cattle indirectly, via human contact.

On Monday, the Department of Environment, Food and Rural Affairs (DEFRA) confirmed a second outbreak in a herd of cattle with clinical signs of FMD as part of its surveillance activity in response to the initial outbreak.

Meanwhile, Merial has responded to a request by DEFRA to make 300,000 doses of strain-specific vaccine, to be produced at the company's Pirbright location, according to Dickinson. The vaccine is not made from live virus, and no decision has been taken on whether to use it, Debby Reynolds, DEFRA's chief veterinary officer, told The Scientist.

One issue that arose with vaccines, in a 2001 FMD outbreak in the UK, was the inability to distinguish vaccinated animals from infected animals. Dickinson wrote in an Email that this concern "is not an issue" because with the current vaccine "we are able to distinguish vaccinated animals from infected ones upon examination."

FMD, a highly contagious viral disease that afflicts cattle, swine, goats, sheep and other animals, is characterized by fever and blister-like lesions on the mouth and hooves. Very few human cases of FMD have been reported, according to DEFRA. The last human case reported in Britain occurred in 1966. The disease in humans, in the very rare cases that have occurred, is mild, short-lived and requires no medical treatment.

Research on FMD in the US occurs in one location, the Plum Island Animal Disease Center, located off the northeastern tip of New York's Long Island. Animal pathogens have never escaped from the facility, which has been operating for nearly 50 years. In 2003, the Department of Homeland Security took over security there.

"It's extremely difficult to see how any of the infected material could have left the lab," said Peter Webbon, chief executive of the Animal Health Trust, which runs an animal disease research facility using similar biosecurity measures in Suffolk, UK. "There are multiple layers of security to prevent that from happening."

But assuming the virus escaped from the research labs, "it spreads very easily" by being blown by the wind, carried in floodwater, or being carried on humans, Webbon said. The virus can last for up to a month, he added.

Webbon said the UK government used the Animal Health Trust facility to investigate the 2001 outbreak, which resulted in the destruction of more than 6 million animals and cost the country £8.5 billion.

He added that his facility has not been affected by the recent outbreak. "All the signs are this is going to be a much, much smaller outbreak," he said. "There are far fewer animals involved."

"I think the government was very good this time," said Duffus. "In 2001, there was some time before [the outbreak] was caught."


Kelly Rae Chi
mail@the-scientist.com

Links within this article:

Health and Safety Executive investigation
http://hse.gov.uk/news/archive/07aug/footandmouth.htm

Institute for Animal Health
http://www.iah.bbsrc.ac.uk/

Merial Animal Health Ltd
http://www.merial.com

R. Walgate, "Will foot and mouth disease vaccines work?" The Scientist, March 27, 2001.
http://www.the-scientist.com/article/display/19550/

DEFRA
http://www.defra.gov.uk/

B.A. Palevitz, "Mary's little lambs," The Scientist, April 16, 2001.
http://www.the-scientist.com/article/display/12357/

X. Bosch, "Foot-and-mouth research at risk," The Scientist, March 24, 2005.
http://www.the-scientist.com/article/display/22633/

Foot-and-mouth disease
http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_ahfmd.html

J.D. Miller, "Big innovations at NY Biolab," The Scientist, June 27, 2006.
http://www.the-scientist.com/news/display/23731/

Animal Health Trust
http://www.aht.org.uk/