In early March 2003 the World Health Organization received reports of an outbreak of acute respiratory illness from Viet Nam and South East Asia.
This has been called Severe Acute Respiratory Syndrome or SARS. The outbreak has continued to grow with nearly 6000 cases now reported in 30 different countries. Of these about 90% have occurred in mainland China or Hong Kong.
While groups of cases have occurred in other parts of the world (eg Canada), so far less than 1 % of cases have been reported in Europe, with no European country reporting more than 10 possible cases and many having none.
The illness is a bit like Influenza and has no unique features. It begins with fever which after an interval of a few days progresses to cough and breathlessness. A chest radiograph will usually show signs of pneumonia.
There is currently no widely available accurate test to confirm the diagnosis and no specific treatments to kill the virus have been found. Treatment is therefore supportive and fortunately most (over 90%) patients recover. Nevertheless about 7% of those reported have died.
A previously unknown virus was eventually found from some of the cases. It appears that it is passed from man to man, mainly by coughing and sneezing, but that it is not as infectious as for example influenza. Fairly close contact with an affected person is required to catch SARS.
For these reasons it should only be suspected in someone who has recently visited an affected area or has been in contact with a known case of SARS.
The continued increase in cases is now mainly occurring in China. In many places SARS appears to be under control, and Viet Nam, where it was first reported, has now been declared free of SARS. Much remains to be learnt about the infection.
Where the virus came from and what will happen in the future is not known, but we have already learnt a great deal about the condition in a very short space of time.
By Mark Woodhead, Department of Respiratory medicine, Manchester Royal Infirmary.
