What it is and how to avoid it

What is Severe Acute Respiratory Syndrome (Sars)?

A serious disease which first seems to have emerged in the Guangdong province of southern China in November last year, although global alerts were not issued until last month. The scientist who sounded the alarm as the disease hit Hanoi in Vietnam has since died from it in Bangkok, Thailand.

There have been deaths in China, Hong Kong, Canada, Singapore , Vietnam, Thailand and Malaysia. Cases have been reported in 16 other countries, including the UK where there have been six cases. About 200 have died, from 3,800 infections.

The World Health Organisation (WHO) is furious that Chinese officials failed to alert them to early signs of an epidemic and later underplayed its seriousness.

What are the symptoms?

High fever, with a temperature of more than 38C (100F), a dry cough, breathing difficulties. Chest X-rays can suggest pneumonia.

How contagious is it?

It seems mainly to be spread through droplets, particularly coughing and sneezing.

Many of the early victims are close relatives, friends or hospital staff who might not have taken sufficiently strong precautions when treating patients with what was an unknown threat.

However, the presence of a large cluster of cases on a Hong Kong housing estate has raised new questions about its virulence.

The symptoms of victims in the former colony, and the hospital staff treating them, seem to be more severe and there are concerns that the disease might already be mutating into a new, more dangerous form.

In Canada, much of the concern has centred around a cluster of 31 suspect and probable cases in members of a charismatic religious group and their close contacts. Health authorities there are struggling to identify every person at potential risk, amid fears the disease might spread to the general community.



What causes it?

Quick cooperation between 13 laboratories in 10 countries has satisfied the WHO that the culprit is a member of the coronavirus family never before seen in humans. A relative is the causes of the common cold. It has probably sprung from close contact with animals.



What is the best treatment?

No one yet knows. Scientists are working to devise effective answers now they know what they are trying to fight. Antiviral treatments and antibiotics have been used so far.

How fast does it travel?

Very, probably thanks to air travel. One of the six British cases had not been to Asia recently, but he had met a businessman who had.

What precautions are being taken?

A number of countries have set up quarantine precautions for people returning home from affected Chinese regions. WHO and the Foreign Office is advising against travel there and Vietnam is thinking of closing its border with China.

However, British health officials think that quarantining students returning to Britain from affected countries would be an over-reaction, given screening arrangements before they are allowed on flights. They recommend monitoring their health.

Should we wear masks?

Surgical masks offer only limited protection at best. Cycle masks against city pollution might be better. But simpler precautions, such as regular washing of hands, are probably a better bet since viruses can spread like wildfire through contact with infected hands or surfaces.