How the 'global village' faced Sars

Airport screening for Sars: Missed cases

Experts are now suggesting that, with the exception of China, the world's first brush with the Sars illness is on the wane.

The number of new cases reported in "hotspots" such as Hong Kong and Toronto are falling away, and public health experts there are hopeful that this trend will continue.

Many countries have so far registered only a handful of cases involving people who were infected in China or Hong Kong, and then developed symptoms after travelling to the UK.

The World Health Organisation says that this is testament to both the efficient response of health systems worldwide - and justification for its swift and decisive action in issuing a global alert in March.

For many years, there has been growing fear among infectious disease specialists that the increase in global air travel could assist a disastrous spread of a new and lethal infection.

Easily spread

It was an unprecedented movement of troops at the end of the First World War in 1918 that precipated to an explosion of Spanish Flu on all continents.

Over the course of the following year, it is thought to have killed more than 50 million people.

Then, continental journeys took weeks - now, a carrier can circle the globe in 24 hours.

Richard Tedder, professor of virology at University College London, told BBC News Online: "What Sars has done is rekindle the concept of the global village.

"Somebody's problem on a peninsula in South East Asia is Toronto's problem a few days later."

What it may prove to be is a very effective dry run - one wonders what will happen next time

Professor Richard Tedder, University College London

Sars was seen as the biggest test so far of whether individual countries could cope with the pressure of infected people arriving daily at their airports.

It demonstrated how it is impossible to stop infected people getting into your country.

Not spotted

England's Chief Medical Officer Professor Liam Donaldson pointed out that none of the six cases of Sars discovered in the UK could have been detected on arrival at the airport.

None had symptoms at this point, so even the most thorough screening process would have failed to pick them up.

The situation in Toronto also revealed how fine the margin is between successful containment of the illness, and failure.

In the Canadian city, doctors had no forewarning that they might be seeing cases of an unusual and contagious pneumonia.

The health system really was not prepared for this

Dr Donald Low, Mount Sinai Hospital, Toronto

As a result, the illness managed to gather momentum before the medical authorities began moving to isolate patients and protect medical staff.

Professor Tedder said: "What happened in Canada - and I mean no criticism by it - is that they failed to recognise an infectious disease in their general wards and in A&E."

It has taken a mammoth effort to wrestle the Toronto outbreak under control.

China's crisis

Dr Donald Low, chief microbiologist at Mount Sinai Hospital in Toronto said: "The health system really was not prepared for this, particularly in the areas of public health and infection control.

"The impact on non-SARS patients has been quite tremendous."

China, of course, is in a far more precarious position.

It is now firmly possible that the disease may become established in the community, and in many provinces.

The enormous efforts currently underway in China - one example is the construction, in just days, of a 1,000 bed isolation camp for Sars patients - may yet not be enough to contain the disease.

And this has implications for the rest of the world.

If China becomes a reservoir for Sars, other countries, particularly its neighbours, will have to maintain constant vigilance for cases arriving from the Far East.

Professor Tedder said it was possible that stringent surveillance precautions would be in place in the UK and Europe for the foreseeble future - and perhaps for years to come.

He said: "What it may prove to be is a very effective dry run - one wonders what will happen next time."

It is time to support an international war on disease.

Dr Barry Bloom, Harvard School of Public Health

"It was still a close call. It remains to be seen whether it has been beaten in Europe - we're not out of the woods yet.

He said that Sars was a "wake-up call" to public health doctors worldwide - and said that one beneficial effect of the outbreaks might be to divert much-needed funding to make sure the UK and other countries are better prepared in future.

"We were lucky this time because it's not terribly well adapted to living in humans at the moment.

"In a year's time, if it becomes well-adapted to humans, it could be much bigger problem."

War on disease

Dr Barry Bloom, Dean of the Harvard School of Public Health in the US, believes that the only way to defeat future epidemics is to make sure that even developing regions of the world have the specialists in place to tackle outbreaks of new illnesses.

Writing in the journal Science on Thursday, he said: "In a world that is increasingly angry at the United States, the lesson here is that it is time to support an international war on disease.

"We should be investing funds to strengthen the health structures in countries around the world.

"This would be the best investment we could make to protect our country and every other against global epidemics, save millions of lives, and change the US image from self-interest to human interest."