Old-fashioned fix foiled new plague

By JEREMY LAURANCE

It looks as if it is all over for Sars - for now.

Severe acute respiratory syndrome, the 21st century's first serious new disease - which came out of China and spread round the world, infecting thousands and killing hundreds - has been put back in its box.

On Tuesday, the World Health Organisation lifted its warning against travel to Beijing, the last place on the globe subject to the ban, and said the most effective weapon against the disease had been the humble thermometer.

By checking the temperature of people with symptoms, and using the old-fashioned methods of isolating those with a fever and quarantining their contacts, the disease's spread had been halted.

"Today is a milestone in the fight against Sars, not only in China but in the world," Shigeru Omi, the WHO regional director for the Western Pacific, told a news conference in Beijing.

More than 20 days have now elapsed since a new case was recorded in the Chinese capital, the city worst hit by the disease. It had 2521 cases and 191 deaths.

The ubiquitous face masks, which came to symbolise tainted cities everywhere, have disappeared from the city's streets.

Only Toronto and Taiwan remain on the WHO list of Sars-affected areas, even though the ban on travel to both destinations was lifted weeks ago.

They have yet to go 20 days without recording a new case, the WHO criterion for declaring them disease-free.

The achievement in lifting the last travel ban is being celebrated by WHO officials, who insist that it was not due to any natural change in the virulence or infectivity of the virus.

New diseases often burn out quickly of their own accord but Sars was defeated only thanks to the "monumental efforts" of Governments, doctors and nurses and a "well-informed and co-operative public". Declaring Beijing open to visitors this week, WHO director-general Gro Harlem Brundtland said: "This is very good news and shows the great progress the world has made against Sars."

But it is not the story's end.

By Monday, the WHO official tally was 8459 cases of Sars and 805 deaths worldwide, recorded in 104 days since the organisation issued its first global warning about a new disease on March 12.

In addition to devastating families, the virus has caused billions of dollars of damage to Asian economies, driven hotels and airlines to the brink of bankruptcy and caused panic worldwide.

It has proved to be one of the fastest-moving viruses in history.

From the 55 cases recorded on the day of the WHO's first warning, the disease exploded within a month to cause more than 3000 cases and more than 100 deaths in 20 countries on all continents.

There was no vaccine, no effective treatment, a high death rate and no way of knowing how far it would go.

The epidemic highlighted for the first time the vulnerability of a globalised society linked by air-travel to the emergence of lethal new pathogens.

The disease originated in southern China, where the first cases occurred last November, and was carried into Hong Kong by a professor of respiratory medicine who had been treating patients with Sars.

He spent a single night on the ninth floor of the Metropole Hotel, Hong Kong, in late February where he infected at least 16 other people, who spread the disease internationally.

One cough in the lift lobby may have been all it took to trigger the worldwide epidemic.

A key factor in the early spread of the disease was the reluctance of the Chinese to admit it was happening.

China only started daily reporting of cases only in early April, and by then Sars had gained a foothold from which it was much harder to dislodge.

And the infection had been transmitted to Hong Kong, one of the world's great travel hubs.

The disease continued to accelerate through March and April, peaking in early May.

Toronto, the first and only Western city to have deaths from Sars, was hit by a WHO travel ban in April which had to be re-imposed 12 days after it was lifted last month, when the city suffered a renewed outbreak.

In Britain only four cases were recorded, and all recovered.

From early March, the WHO's global network of 11 laboratories worked round the clock to identify the virus and investigate how it was transmitted.

By early April it was established as a member of the coronavirus family, a cause of the common cold, and soon afterwards it was traced to a species of the civet cat, a delicacy in southern China.

But it remains uncertain whether the civet cat is the original host for the virus or had picked it up from another animal or even from a human keeper as the animals are bred in captivity.

The biggest unknown about the virus is: will it recur?

Toronto's experience of a second outbreak proved that even in a sophisticated Western city, the virus has the capacity to evade modern methods of surveillance.

Continued vigilance will be needed for at least a year, says WHO, to ensure the chain of person-to-person transmission is broken.

Even then Sars may have found an animal host or other place in nature in which to hide, as the Ebola virus does, from which it could return again, when conditions are right.

The most urgent challenge for scientists working on the virus is to develop an accurate, quick diagnostic test so that if a new outbreak should occur it can be rapidly identified and contained.

Otherwise, Sars could yet spread mayhem through the world for a second time.

- INDEPENDENT