How safe is biosafe?
Dressed in blue scrubs and disposable underwear, Simon Caidan cautiously transfers liquid into a series of bottles 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 leakage, 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 bio-security 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 bio-safety for the World Health Organization 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 bio-security 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 bio-security 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 a
nd prevent.
生物安全有多安全?
身穿蓝色防护服和一次性内衣, 西蒙﹒凯旦小心谨慎地将液体转移到面前密封柜中的一套小瓶子里。他将双臂伸进封帖在玻璃上的一副手套里，直至肘部，以防接触盗柜子里那具潜在致命性的物质。
这是英国最为安全的科研实验室之一，位于伦敦北部郊区，从事世界上一些最具危险性疾病的研究。保存在这里的病原体具有非常大的危险性，因此实验室内的气压维持在低于外界气压的状态，以确保开门时不会发生任何泄露。
所有经由实验室流通的空气都经过数次过滤，以除去哪怕最微小的颗粒，同时，工作人员在进入前必须除掉所有衣物，而且沐浴后才能离开。如果发生泄漏，整个实验室都要封闭，进行熏蒸消毒。
然而，尽管采取了这些严密的安全措施，据认为还是有一个与其类似的实验室发生了口蹄疫病毒泄露，感染了附近的牲畜。关于萨里郡诺曼底所暴发的口蹄疫疫情的初步报告，把矛头指向了位于3英里之外皮尔布赖特的一所高安全性实验室。这所实验室由政府资助的动物卫生研究所和私营的英国梅里亚尔药品公司共管。
该事件引发了人们对英国安全实验室的状况及其所构成威胁的严重关切。如果病毒能从这样的实验室外泄，那么此类事件是否会再次发生？而下一次，病毒是否会从研究致命性人类疾病的实验室外泄？
英国拥有15所“四级防护”实验室，即全国最高生物安全级别实验室。每所实验室所研究的都是一些已知的对人和动物最致命的微生物：最有高度传染性的疾病，哪怕是最小剂量也会致命，而且绝无治愈的可能。
“我很惊讶，在所有那些地方中，偏偏是在英国发生了泄露，”世界卫生组织及瑞典传染病研究所的生物安全专家英格德﹒克林斯博士说，“你们已经制定了严格的规章制度啊。”在克林斯博士可看来，口蹄疫病毒外泄到皮尔布赖特实验室附近的乡村，表明了世界生物安全措施中存在的薄弱环节：人。
“归结到一点，就是工作人员态度松懈，”她说，“你的确不能把泄露的原因归为设备老化，因为归根结底生物安全不是一个技术问题。”
她和其他科学家所担心的是，严格的规章制度和安全措施会因粗心大意而变得毫无用处。恪守安全议定书是件令人厌烦的事，研究人员会染上各种坏习惯或变得满不在乎。例如，在错误的水池冲洗被污染的物品，携带被感染的样品穿梭于各个房间，或者未经适当消毒就将设备带出实验室。所有这一切都难以进行监督和预防。
Malicious behavior is even harder to co
ntrol, 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 radicalized 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 organization 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 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.
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.
如果一名工作人员决意把病毒偷偷带出实验室，那么这种恶意行为就会更加难以控制。最近格拉斯哥机场遭到的恐怖袭击表明，医生和科学家与其他人一样也会变成激进分子，很多专家也指出，使大量危险性病菌唾手可得是件愚蠢的事。
设备本身也有问题。简单的家用电淋浴----比如凯旦先生供职的国家医学研究所所使用的那种-----能够冲洗掉所有病毒残余吗？
“实验室事故的发生比公众所知道的要频繁，”来自监控生物制剂使用的非赢利机构“阳光计划”的埃德﹒哈蒙德说，“这些事故并不像英国的这起这样惊人，不过我觉得，的确存在一种否认问题严重性的现象。”
2004年，一位从事埃博拉病毒疫苗研究的俄罗斯科学家因被注射器扎伤了手而身亡；2005年4月，美国一家实验室在发往全世界科学家的试验箱中，不慎放入了一种亚洲型流感病株，导致病毒外泄。最近的一个为人所知的天花感染事件发生在1978年，当时伯明翰大学的一名研究人员受到感染。到目前为止，尚没有一起实验室事故导致公众死亡。
但是社会活动人士担心，随着对这些危险微生物研究的日益增多，事故和外泄的风险也在增加。保存在“四级防护”实验室中的病毒都属于最具传染性的病毒。这些微小的生物体只需极少的一点就能致病。一旦外泄，就会迅速扩散，几无控制的可能，也没有有效的治疗方法。
在国家医学研究所，科学家们正从事H5N1型致命性禽流感病毒的研究。从感染者身上获取的样本被带到伦敦米尔西尔的实验室进行分析。同时，研究人员也一直在研究1918年流感病株，那场流感造成大约5000万人死亡。如果该病毒的病株外泄，就会导致新一轮大流感暴发，因为几乎没有人能对其免疫。
“这就是规章制度必须如此严格的原因，”实验场地安全负责人凯旦先生解释说，“我们不只是在保护自己的工作人员，而且也是在保护环境和公众。”
那么我们为什么还要冒此风险呢？“我们需要对这些微生物进行研究，这样才能更好的了解它们，找到对付它们的办法，”布里斯托尔大学动物病毒学家菲利普﹒达弗斯说，“我们还需要研究样本，以诊断这些病毒。”
尽管针对口蹄疫病毒如何从皮尔布赖特
外泄的调查仍在继续，人们已经开始怀疑这个实验室是否还适于使用。同时，人们也在质疑梅里亚尔公司和动物卫生研究所共管的这所实验室排出的液体废物是否经过了充分处理，杀死了其中含带的任何病毒，而调查人员也仍在调查该病毒是否有被工作人员带出实验室的可能。
一名最近参观过皮尔布赖特实验室的高级实验室安全专家也对日益老化的设备能否有效维护生物安全表示担忧。“我所见到的情况非常令人震惊，”他说，“那里有优秀的科学家，但是设备太老了，与更为现代化的设备相比，出错的可能性更大。”
不管疫情暴发的原因是什么，英国高安全性实验室的安全必须得到加强。世界卫生组织明年将发布危险性病原体保存的国际新标准。致命性人类病毒外泄造成的恐惧令身着白大褂的试验人员脊骨发凉。