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(2007-08-21 16:42:08)


分类: 英语学习
How safe is biosafe?

By Richard Gray
If foot and mouth can escape from an animal laboratory, can we trust the high-security labs that study deadly human diseases?

Dressed in blue scrubs and disposable underwear, Simon Caidan cautiously transfers liquid into a series of vials inside the airtight cabinet in front of him. His arms are pushed up to his elbows in a pair of gloves sealed to the glass, preventing him from coming into contact with the potentially deadly material inside.
This is one of the most secure research laboratories in Britain, dealing with some of the world's most dangerous diseases. The threat posed by the pathogens kept here, on the outskirts of north London, is so great that the rooms are maintained at a lower air pressure than the outside to ensure nothing can escape when the doors are opened.
All the air passing through the building is filtered several times to strip it of even the finest particles, while staff have to remove all clothing before entering and must shower before leaving. If there is a spillage, the entire laboratory can be sealed and fumigated.
Yet, despite these formidable safety measures, it is from a laboratory similar to this that a foot and mouth virus is thought to have escaped, infecting nearby livestock. Initial reports into the outbreak in Normandy, Surrey, have pointed to a high-security laboratory in Pirbright, three miles away, shared by the government-funded Institute for Animal Health and a private drug firm, Merial UK.
The incident has sparked grave concerns about the state of the country's secure laboratories and the threat they pose. If a virus can escape from one such laboratory, can it happen again? And next time, could it be from a lab handling deadly human diseases?
In Britain, there are 15 "Containment Level Four" laboratories, the maximum biosecurity level, across the country. Each handles some of the deadliest organisms known to man and animals: diseases that are highly infectious, fatal even in low doses and impossible to treat.
"I am surprised there has been a release from a facility in the UK, of all places," said Dr Ingegerd Kallings, an expert on biosafety for the World Health Organisation and the Swedish Institute for Infectious Disease Control. "You have good regulations in place." For Dr Kallings, the escape of foot and mouth into the countryside around the Pirbright laboratory illustrates the weak link in the world's biosecurity measures: people.
"It comes down to a lax attitude among the staff," she said. "You can't really blame the age of a facility for an escape, as ultimately the biosecurity is not a technical issue."
What she, and other scientists, fear is that the tight regulations and safety measures can be rendered useless by carelessness. Adhering to safety protocols is tedious, and researchers can pick up bad habits or become complacent. Washing contaminated material down the wrong sink, for instance; carrying infected samples between rooms, or removing equipment from the laboratory before it has been properly decontaminated. All are hard to monitor and prevent.
Malicious behaviour is even harder to control, if a member of staff decides to smuggle a virus out of a facility. Doctors and scientists, as the recent terrorist attacks on Glasgow airport showed, can be radicalised like anyone else and many experts have pointed at the folly of keeping stocks of dangerous diseases so readily at hand.
Then there are the facilities themselves. Can a simple household electric shower, as used in the National Institute for Medical Research where Mr Caidan works, for instance, remove all traces of a virus?
"Lab accidents happen more frequently than the public knows," says Ed Hammond, of the Sunshine Project, a non-profit-making organisation that monitors the use of biological agents. "They are not always as spectacular as the one in the UK, but I believe there's a real culture of denial about the scale of the problem."
In 2004, a Russian scientist working on an Ebola vaccine died after pricking her hand with a syringe, while in April 2005, a pandemic strain of Asian flu was released by a laboratory in America after it was accidentally put into test kits sent to scientists around the world. The last known case of smallpox occurred in 1978, when a researcher at Birmingham University was infected. No lab accident has resulted in the death of a member of the public… so far.
But campaigners fear that, with more and more research being carried out on these hazardous organisms, the risk of accidents and escapes is increasing. The viruses kept in Containment Level Four laboratories are among the most infectious. Just a few of the tiny organisms are needed to cause disease. Once out in the community, they would spread quickly, with little chance of controlling them, and there are effective treatments for few of them.

At the National Institute for Medical Research, scientists are studying the deadly H5N1 avian flu virus. Samples from infected people are brought to the facility in London's Mill Hill for analysis. Researchers have also been working on the 1918 pandemic flu strain that killed about 50 million people. If this strain of the virus were to escape, it could cause a fresh pandemic, as virtually no one would have immunity.
"This is why the regulations have to be so strict," explains Mr Caidan, the head of safety for the site. "We are not just protecting our staff, but the environment and the general public."
So why are we taking the risk at all? "We need to carry out research on these organisms so we can understand them better and produce ways of treating them," says Prof Philip Duffus, an animal virologist at Bristol University. "We also need to handle samples for diagnosis of these diseases."
While the investigation into how the foot and mouth virus escaped from the Pirbright site continues, there are now doubts as to whether the laboratory is still fit for purpose. There are also questions about whether liquid waste from the Merial buildings and the Institute for Animal Health laboratory was treated sufficiently to kill any virus it contained, and investigators are still examining whether the disease could have been carried off the site by a member of staff.
One senior laboratory safety expert who recently visited the Pirbright laboratories has also raised concerns about the ability of the ageing facilities to effectively maintain biosecurity. "What I saw was quite shocking" he said. "There are some good scientists there, but the facilities are so old that the chances of making a mistake are much greater than at more modern facilities."
Regardless of the outbreak's cause, the safety of Britain's high-security laboratories will have to be improved. The WHO will publish new international standards for containing dangerous pathogens next year. The fear of the escape of a deadly human virus is sending many a shiver down white-coated spines. 
                                                                                  摘译自The Telegraph Aug. 14, 2007


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