Severe Acute Respiratory Syndrome

What is Severe Acute Respiratory Syndrome (SARS)? 

SARS is the term used to describe a serious respiratory illness. The first global outbreak occurred between March and July 2003, with over 4,300 cases and 813 deaths. China, south east Asia, and Toronto, Canada were the most affected countries (1). 

What are the main symptoms of SARS? 

The main symptoms of SARS are high fever (>38° C), dry cough, shortness of breath, or breathing difficulties (2). Other symptoms can include myalgia, headache and diarrhoea (3). Symptoms should be severe enough to warrant hospitalisation and chest X-ray changes should show pneumonia or respiratory distress syndrome.  

How contagious is SARS?

Reports from countries most affected by SARS show that close contact with a symptomatic person poses the highest risk of the virus spreading from one person to another. The majority of cases occurred among hospital workers who have cared for SARS patients and the close family members of these patients (4-6).  

What is the cause of this infection? 

The cause of SARS is now known to be a new member of the coronavirus family. The SARS coronavirus (SARS CoV) has been isolated and further research is underway (7, 8, 9).  

What is the treatment for SARS?

There is a wide clinical spectrum in SARS. Most patients have recovered with minimal treatment, but for the severely ill, reports from affected countries suggest that anti-viral drugs are probably not beneficial (6), however other research suggests that interferon may be helpful (10). In addition, steroids may be effective in some patients (6), research into this area is continuing. At present, there is no specific treatment.  

How fast does SARS spread?

SARS appears to be less infectious than influenza. The incubation period is believed to be short, around two to seven days (maximum 10 days) (5, 6, 11).  

Is there a vaccine for this? 

No, a vaccine is not available.  

Is there a test for SARS?

There is currently no test available that can detect SARS reliably at the early stages of the illness.There are several types of test for the SARS coronavirus, the main tests are PCR and serology.These tests are only performed on specimens from people suspected of having SARS.

The tests are still under development, and may not be sufficiently sensitive to identify the virus in all cases during the acute illness. A blood test 21 days after the acute illness is the WHO recommended test to see if a person was infected with the SARS coronavirus. If a person has a positive test for the SARS corona virus it means they are, or recently were, infected with the virus. Having a negative test by PCR for the SARS coronavirus does not, however, mean that a person is definitely not infected.  

How many cases of SARS have been reported to date? 

Between March and July 2003, 8,437 probable cases of SARS were reported in 32 countries (1). For the latest number reported cases worldwide, please refer to the WHO website at <>. During the global outbreak, the UK had four probable imported cases.

Between July 2003 and May 2004, four small and rapidly contained outbreaks of SARS have been reported; three of which appear to have been linked to laboratory releases of SARS-CoV (12). The source of the fourth outbreak remains unclear, although epidemiological investigations focused on an animal source.  

Could this result from terrorism?

There is no indication that SARS is linked to terrorism.

Travel and SARS

What should I do if I am planning to travel, and am worried about SARS? 

During the first global outbreak of SARS, WHO issued travel recommendations for travellers to postpone travel to areas with local transmission in a bid to interrupt the transmission of the virus internationally. From 5 July 2003, no travel restrictions or recommendations have been imposed as there are no countries on the WHO’s list of areas with recent local transmission. The latest information and advice is available at <>.


Has SARS gone for good? 

There have been four small and rapidly contained outbreaks of SARS in the world between July 2003 and May 2004. Public health systems are continuing to be vigilant and prepared for the possible global re-emergence of SARS.

We are confident that we have strong surveillance systems in place in the UK to identify new cases of SARS. We have good infection control measures in place in hospitals in this country and have issued advice for health care professionals on the management of SARS case and their contacts to minimise any potential spread of this illness.The latest information worldwide is available at<.

(Source: HPA)


(1) World Health Organization. Cumulative number of reported probable cases of Severe Acute Respiratory Syndrome (SARS). Geneva: WHO, 2003. [online] [cited 28 August 2003]. Available at

(2) World Health Organization. Alert, verification and public health management of SARS in the post-outbreak period. Geneva: WHO, 14 August 2003. [online] [cited 28 August 2003] Available at

(3) Rainer TH, Cameron PA, Smit D, Ong KL, Hung AN, Nin DC et al. Evaluation of WHO criteria for identifying patients with severe acute respiratory syndrome out of hospital: prospective observational study. BMJ 2003; 326: 1354-8.

(4) World Health Organization. Update 58 – First global consultation on SARS epidemiology, travel recommendations for Hebei Province (China), situation in Singapore. Geneva: WHO, 2003. [online] [cited 28 August 2003]. Available at

(5) Booth CM, Matukas LM, Tomlinson GA, Rachlis AR, Rose DB, Dwosh HA et al. Clinical features and short-term outcomes of 144 patients with SARS in the greater Toronto area. JAMA 2003; 289: 2801-9.

(6) Lee N, Hui D, Wu A, Chan P, Cameron P, Joynt GM et al. A major outbreak of severe acute respiratory syndrome in Hong Kong. N Engl J Med 2003; 348: 1986-94.

(7) Peiris JS, Lai ST, Poon LL, Guan Y, Yam LY, Lim W et al. Coronavirus as a possible cause of severe acute respiratory syndrome. Lancet 2003; 361: 1319-25.

(8) Drosten C, Gunther S, Preiser W, van der WS, Brodt HR, Becker S et al. Identification of a novel coronavirus in patients with severe acute respiratory syndrome. N Engl J Med 2003;348:1967-76.

(9) Ksiazek TG, Erdman D, Goldsmith CS, Zaki SR, Peret T, Emery S et al. A novel coronavirus associated with severe acute respiratory syndrome. N Engl J Med 2003; 348: 1953-66.

(10) Cinatl J, Morgenstern B, Bauer G, Chandra P, Rabenau H, Doerr HW. Treatment of SARS with human interferons. Lancet 2003; 362: 293-4.

(11) Wong GW,.Hui DS. Severe acute respiratory syndrome (SARS): epidemiology, diagnosis and management. Thorax 2003; 58: 558-60.

(12) World Health Organisation. Investigation into China's recent SARS outbreak yields important lessons for global public health. Western Pacific Region: WHO, 2004. [online] [cited 22 November 2004].