Severe Acute Respiratory Syndrome (SARS) is the name that has been given to a serious illness, affecting the lungs, which has arisen in the last few months. SARS seems to have started in China, and is much more common in East and South East Asia but is now being reported from other countries around the world.

Before it was given the name SARS, it was sometimes referred to as atypical pneumonia, as it involves infection of the lungs (pneumonia) but not with the usual type of infection (atypical means not typical). The term "atypical pneumonia" has, over the years, included a number of other specific infections and certainly does not mean exactly the same as SARS. Some experts consider that the term is unhelpful and should not be used.

The symptoms are like many other respiratory infections, and you should not be unduly alarmed if you have not been to one of the affected areas and have had no contact with a known case of SARS.

Contact your doctor if:

• You have have recently (in the last 10 days or so) returned from one of the high risk areas, or you have been in contact with someone known to have SARS,
• and you develop a fever (with a temperature of 38°C / 100.4°F or more)
• and you have a cough, shortness of breath or difficulty breathing.

It is thought that SARS may be caused by a type of virus (a new Coronavirus) but work is going on worldwide to identify the cause.

Incubation period

The incubation period seems to be between 3 and 6 days.

Infectivity

It appears that SARS is not as easy to catch as influenza, and those most likely to catch it are the family of an infected person, or hospital workers caring for them.

Direct physical contact is one of the major methods by which people seem to catch it, and attention to hand washing with soap and water is important after contact with infected people. (This applies to many other infections and makes general sense.)

Infection may be spread by coughing, and this explains why we see images on the news of people wearing masks. Masks do help to reduce that sort of spread. Those working with people known to have SARS are advised to take further precautions, wearing eye goggles and clinical gloves.

Hospitals caring for such patients are encouraged to use separate rooms, if possible kept at a lower pressure than normal air pressure. (So that air is sucked in rather than being allowed to escape.)

There is no known specific cure at present, but most people (80 to 95%) get over this infection. However those affected should have the best possible supportive treatment, to enable them to make a recovery, and should be isolated in order to prevent spread of the condition. It is important to seek medical advice if you think it likely that you may have SARS.

The main advice, where possible, must be to avoid contact with infected people. Therefore travel to affected areas should be carefully considered.

We have to guided by the experts, and the links below provide useful, up to the minute advice.

• World Health Organization
• UK Health Protection Agency
• Centers for Disease Control and Prevention (with information in English, Chinese, French, Japanese, Korean, Spanish, and Vietnamese)
• Public Health Agency of Canada
• UK Department of Health advice and travel information [Archived copy]
• BBC News Timeline: SARS virus