One of the abiding images of the swine flu outbreak is the pictures from Mexico of people wandering the streets wearing masks.

自从猪流感爆发以来，墨西哥街头来往人群戴口罩的场景已经成为电视上常见的镜头之一。

And as the disease has spread from country to country, reports have emerged of people purchasing all sorts of products on the internet.

随着猪流感在世界范围内的扩散，人们上网购买各类口罩的消息便不断传出。

But while the scramble is understandable, experts are sceptical about just how useful they are.

人们这样做尽管可以理解，但不少专家依旧质疑这样做的效果。

Professor John Oxford, a virologist at leading London hospital, said: "Really, there is very little evidence that masks actually offer much protection against flu.

伦敦医院的病毒学家约翰·奥克斯福德教授表示，戴上口罩就能预防流感的证据十分微薄。

"I think handing them out to the public as has happened in Mexico just destroys confidence."

他说，"我觉得像墨西哥现在这种给公众发口罩的行为只会摧毁人们的信心。"

It is these sorts of issues that has prompted officials from groups such as the World Health Organization and England's Health Protection Agency to steer clear of calling for them for general public use.

正是由于上述的这些因素，诸如世界卫生组织以及英国保健局之类的官方机构一直拒绝倡导公众都要戴口罩。

While Mexico has handed them out to members of the public, most other countries, including the UK, are just reserving them for health staff.

墨西哥给公众发口罩，而包括英国在内的大多数国家，目前还只是主张医护人员需要佩戴口罩。

Others, such as Belgium, have bought some for flu patients, while several, including Spain, have handed them out to passengers on planes returning from affected areas.

其他国家的反应不一。比利时给流感病人购置了一批口罩，而西班牙则在从感染区返航的飞机上给乘客发送口罩。

Health workers have been told to wear them, along with special gloves, if they are in contact with potential victims.

医护人员在接触疑似病例的时候，需要佩戴口罩和特制的手套。

Professor Oxford believes this approach is right.

奥克斯福德教授肯定了这种做法。

"They are the people who will be most likely to be coming into contact with the virus and the ones who could be passing it on."

"他们是最可能接触到病毒，并且最可能传播病毒的一类群体。"

Dr Ronald Cutler, deputy director of biomedical science at the University of London, said: "If you sneeze with a mask the virus will be contained so from that point of view if everyone wore them it might stop the spread.

伦敦大学生理医学副总监罗纳德·卡特勒医生表示，如果感染病毒的人打喷嚏的时候带着口罩，那么可以防止把病毒传染给别人。从这个角度来讲，只要大家都带口罩，就能限制病毒传播。

"Or you could get the people with flu wearing them, but by the time they are diagnosed it could be too late.

"不过给确诊的病人戴口罩恐怕为时已晚，因为从病毒潜伏到确诊已经有一段时间了。"

"And the problem is that when someone sneezes they tend to take a mask off. I think masks give people a false sense of security.

"另一个存在的问题是，很多戴口罩的人真打喷嚏的时候还是会先把口罩摘掉，所以我认为口罩给人们的是一种错误的安全感。"

"They are not bio-chemical suits. Masks are obviously just covering one part of the body so your hands and clothes could all have the virus on and when you take them off you will infect yourself. "

"口罩并不是生化产品，它们显然只能保护身体的一部分。手上、衣服上同样会携带病毒，当你脱衣服的时候，你就可能被感染。"

"However, because people are wearing a mask they will think they are protected and may go into crowded areas.

所以，人们不能因为戴了口罩就掉以轻心，想当然地进出拥挤场所。

"The best advice is to wash your hands and cover your mouth when sneezing."

"最好的办法就是洗手，并在打喷嚏的时候用手遮住口部。"