Indonesian students and their teacher wear surgical masks in attempt to protect themselves from the severe acute respiratory syndrome, or SARS, at a Jakarta school on April 8. (AP Photo)

SARS: Frequently asked questions

By Reuters

ON THE WEB Learn more about SARS online. Centers for Disease Control World Health Organization Boston Public Health Commission Mass. Dept. of Public Health

Following are facts about the Severe Acute Respiratory Syndrome and what medical experts are saying about it:

WHAT IS IT?

- Scientists say SARS is caused by a new virus from the family of coronaviruses, which also causes the common cold.

The World Health Organisation (WHO) says the disease originated in China's southern province of Guangdong, before spreading to Hong Kong, where it was then carried around the world by air travellers.

Hong Kong and WHO scientists say the strain may have originated from animals although it does not appear anything like any known human or animal viruses.

Health experts in Hong Kong have ruled out any association with influenza A and B viruses, and the H5N1 bird-flu virus which killed six people in the territory in 1997, and one in February.

SARS is a type of atypical pneumonia, which is usually caused by viruses, such as influenza viruses, adenovirus and other respiratory viruses, according to Hong Kong health officials.

WHO says there is no indication SARS is linked to bioterrorism.

WHAT ARE THE SYMPTOMS?

- WHO says the main symptoms are fever above 38 C, chills, muscle aches, a dry cough and breathing difficulties. Changes in chest X-rays, which are indicative of pneumonia, also occur.

Health experts say the disease has an incubation period of between 2-16 days, with 3-5 days being more common, before victims start showing flu-like symptoms.

HOW DANGEROUS IS IT?

- The mortality rate appears to be 3 to 5 percent, far more than influenza. In Hong Kong, at least, those who are infected invariably develop severe pneumonia, which can cause numerous complications. Conditions of victims deteriorate very quickly, in as little as five days.

Some health experts say because the disease has spread so far and so fast it is now probably entrenched in the population and could be here to stay.

HOW ARE PATIENTS TREATED?

- There is currently no specific cure for the disease. But doctors worldwide have been treating it with ribavirin -- an anti-viral drug -- and steroids.

HOW DOES IT SPREAD?

- WHO and Hong Kong experts say the virus spreads through droplets by sneezing or coughing and such direct infection can usually occur within a radius of about 3-6 feet (1-2 metres).

The virus can also spread indirectly as it can survive outside the human body for three to six hours. Contact with any object that is tainted by droplets containing the virus, for example, a contaminated phone, could lead to infection if a person then touches their eyes, nose or mouth.

HOW FAST DOES IT SPREAD?

- WHO says SARS appears to be less infectious than influenza, and is not highly contagious when protective measures are used.

WHO IS MOST LIKELY TO BE INFECTED?

- The virus is highly concentrated in discharges such as mucous or phlegm when the victim is very sick. Therefore, the virus has tended to spread primarily to health care workers treating victims or close family members of victims.

- Patients who are having the most severe complications and dying from SARS are either older people or those with underlying health problems like congestive heart failure, lung disease or hepatitis, though some children have contracted it.

IS IT SAFE TO TRAVEL?

- WHO has warned travellers to avoid Hong Kong and the southern Chinese province of Guangdong.

People who have the symptoms above and have been in close contact with a person who has been diagnosed with SARS, or have a recent history of travel to areas where cases of SARS have been spreading, should seek medical attention.

WHAT CAN I DO TO AVOID SARS?

Doctors recommend extra care with hygiene: washing hands often with soap, and avoiding touching the mouth, eyes or nose.

Doctors in Hong Kong recommend that people use masks.

Health experts also advise getting plenty of rest and maintaining a healthy diet. Exercise is also important, but swimming is not recommended due to fears that the virus could also be waterborne.