Vaccine Lab Implicated as Source of FMD Outbreak

Foot and mouth disease (FMD) is so highly contagious--and such a threat to farm economies--that the United States won't allow researchers to work with the virus on the mainland. But in Britain, a lab making Foot and Mouth vaccines was located near herds of cattle and might have been the cause of a new outbreak.

FMD does not typically infect humans, but its appearance among farm animals can have a swift and far-reaching economic impact--several countries, including the United States, have banned imports of British livestock, and Britain has suspended exports of livestock, meat, and milk products and destroyed more than 100 cows since the outbreak was discovered last week.

(Horses cannot be infected by FMD, but can carry the virus on their hooves, skin, hair, and possibly in their nasal passages.)

Britain's health and safety agency says there was a "strong probability'' the outbreak originated at the Pirbright laboratory southwest of London and was spread by human movement. The laboratory houses both a government Institute for Animal Health research center and vaccine-maker Merial Animal Health.

Lab accidents have resulted in human cases of everything from meningitis to Ebola, but are rare and most are self-contained. Still, diseases that can kill humans have made it out of labs.

"With the amount of virus there is in laboratories around the world, I'm surprised that this kind of thing doesn't happen more often,'' said Juan Lubroth, DVM, PhD, Dipl. ACVPM, head of infectious diseases at the Food and Agriculture Organization.

FMD is the most contagious disease among mammals. In the United States, which has been free of the disease since 1929, it is illegal for anyone to possess the virus outside of a single research laboratory on Plum Island, New York. Germany employs the same policy. Some experts think that by restricting the virus' use to an island, even in the event of an outbreak, it would be self-contained.

But others say that isn't necessary. In Canada, Switzerland, Spain, South Africa, Botswana, China, and Egypt, the virus is regularly handled in laboratories on the mainland without major problems.

"With today's technology, you can do very safe work without having to be on an island,'' Lubroth said.

Andrea Morgan, DVM, associate deputy administrator in the veterinary services department at the U.S. Department of Agriculture, agreed. "Regardless of whether the virus is on an island or on the mainland, it all comes down to respecting the proper biosecurity measures,'' Morgan said.

According to a 2002 government review, parts of the research center suspected in the British outbreak were deemed to be "shabby,'' although no biosecurity concerns were raised. The National Farmers' Union has for years expressed concern that the center was vulnerable to a lab accident. Plans are in place to rebuild it by 2011, at a cost of $245 million.

The drug company being investigated in the outbreak insisted there had been no violation of its biosecurity procedures.

"To date, we have not been able to establish any evidence that the virus may have been transported out of our center by humans,'' said Merial Animal Health, the British arm of U.S.-French Merial Ltd.

Experts believe a laboratory connection is likely.

"It seems a little bit too coincidental that the strain of the Foot and Mouth virus causing the outbreak was the same one being used in a laboratory five miles away,'' said Freda Scott-Park, BVM&S, PhD, MRCVS, former president of the British Veterinary Association.

"This would not be the first time that we've had an event linked to a virus escaping from a lab,'' said Dr. Bernard Vallat, director-general of the World Organization for Animal Health. He noted that Britain's rapid response should ensure the outbreak is properly contained.

Though agencies like the Food and Agriculture Organization, the World Health Organization and the World Organization for Animal Health make recommendations for handling dangerous viruses and bacteria, they are just that: recommendations. Countries are free to either respect or ignore them.

The World Organization for Animal Health says Foot and Mouth warrants the highest containment level possible. Among its recommendations are that sewage be treated to ensure infectious material is destroyed and that staff shower and change clothes before leaving the lab. Experts also recommend that labs working with the virus be isolated from animals that could be infected.

Concerns about biosafety were triggered after three laboratory-related outbreaks of severe acute respiratory syndrome in Singapore, Taiwan and China in 2003 and 2004. In Singapore and Taiwan, lab workers inadvertently infected themselves. That was also the case in China, where the infection spread from two lab workers to seven family members and contacts outside the lab.

In 2005, scientists worldwide scrambled to avert a possible global flu outbreak by destroying samples of the 1957 flu pandemic virus that were accidentally sent to 5,000 labs in 18 countries.

Though WHO says many laboratory practices have improved since the SARS accidents, much remains to be done.

"We can try to mitigate the risk, but zero risk is probably one of things we can never achieve,'' said Dr. Nicoletta Previsani, project leader of WHO's global biosafety and biosecurity program.

"It's like when you work in your own kitchen preparing dinner,'' Previsani said. "You do your best, but sometimes you still cut yourself with a knife.''

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The Associated Press

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