Questions and answers
CBC News Online | Updated August 14, 2003
The World Health Organization calls Severe Acute Respiratory Syndrome, or SARS, a new communicable disease that is a global health threat. As of July 11, 2003, more than 800 people worldwide had died from the disease, which has spread around the globe by air travel.
Here's a look at what is and isn't known about the mysterious disease:
What are the symptoms?
The disease spreads from person to person. It often begins with a high fever, headache and sore throat. Other possible symptoms include loss of appetite, confusion, rash and diarrhea. Not everyone has reacted the same way.
The WHO said doctors are on the lookout for those symptoms with:
The respiratory symptoms appear two to 10 days after exposure.
- a fever over 38 C AND
- cough, shortness of breath, difficulty breathing AND
- close contact with someone diagnosed with SARS or a history of travel to affected areas, including Toronto, Vancouver, Guangdong province in China, Hong Kong, Singapore and Hanoi, Vietnam.
Health officials in Ontario say relying on exposure to known contacts of cases is no longer reliable. All respiratory illnesses should be treated as SARS until proven otherwise.
What causes SARS?
On April 16, the WHO identified the virus that causes SARS. Researchers said the coronavirus is new to humans but scientists haven't been able to find it in all probable specimens, an important step in confirming the cause.
Scientists in the Netherlands infected monkeys with the coronavirus suspected of causing SARS. The animals developed the same symptoms as humans with SARS, a crucial step in verifying the cause of the disease.
Canadian and then U.S. scientists mapped the genome of the SARS coronavirus. Now researchers in Hong Kong are looking for genetic mutations that may make the virus more virulent.
Researchers at the University of Hong Kong say SARS probably spread to humans from animals. They're testing pigs and poultry for the virus.
What are the risks?
Health officials say the risks are low for most Canadians.
"If someone is in close contact with one of the probable cases they are at greater risk," said Dr. Colin D'Cunha, Ontario's Public Health Commissioner, on March 23. "For members of the general public, the risk appears to be otherwise slim and near zero." He added there is no evidence it spreads through casual contact.
As of March 30, Health Canada defines a "suspect" case of SARS as a person who fits into one of the following two categories: a person who develops fever and one or more respiratory symptoms within 10 days of returning from travel to areas in Asia where SARS cases are being reported, or a person who develops fever and one or more respiratory symptoms within 10 days of having had close contact (i.e. within one metre) with a "probable" case of SARS.
"Probable" cases of SARS often have a more severe illness, with progressive shortness of breath and difficulty breathing, and in some cases, chest X-rays show signs of atypical pneumonia.
Dr. Jay Keystone, a travel and tropical disease specialist with the University of Toronto, said close contact is needed with someone who is infected. Ninety per cent of cases have been in unprotected health care workers, who have had direct contact with respiratory secretions (sneezes, coughs, nasal fluids) of SARS patients.
He added SARS is moving quickly around the world because of air travel, but it isn't spreading rapidly within the community.
How can the risks be minimized?
Health Canada advises people can minimize the risk of infection by:
- regular and thorough hand-washing for at least 20 seconds using soap and warm water
- checking travel advisories
- refraining from donating blood if they have been to a SARS-affected region within the last 10 days
- seeking immediate medical advice if they feel they have symptoms of SARS
Where did SARS originate?
WHO has reported hundreds of cases in Hong Kong and Vietnam since February. An outbreak of pneumonia with similar symptoms struck Guangdong province in China last November and was brought under control in mid-February.
Doctors in Hong Kong focused their investigation on a hotel where seven guests contracted the ailment from a Chinese professor and carried it to Vietnam, Singapore and Canada.
No one knows how the disease spread in the hotel. Health officials have speculated the professor sneezed or coughed by an elevator. One expert pointed to the hotel's air conditioning system, but none of the hotel workers have become sick.
What are governments doing?
On March 25, SARS became a reportable, virulent, communicable disease in Ontario. The change allows public health officers to quarantine infectious people and their family members for up to 10 days to track the disease and prevent it from spreading.
The Ontario government has set up an around-the-clock command centre to co-ordinate information on the spread of the virus. People with general questions about SARS can call Telehealth Ontario at 1-866-797-0000 to speak to a registered nurse.
Canadian, provincial and local health officials are working together to enhance surveillance and look for additional cases, including those arriving on international flights. Sick passengers are assessed in separate rooms and promptly taken from the airport to hospital.
Laboratories around the world, including the National Microbiology Laboratory in Winnipeg, are trying to determine the origins of the disease and develop diagnostic tests. They are also screening potential treatments.
On the other side of the Pacific, health officials in Singapore have quarantined more than 500 people who may be at risk. In Hong Kong, officials have called for all schools to be disinfected. Children with infected family members must avoid classes for a week.
Candian Blood Services says people who have travelled to SARS-infected countries in Asia will have to wait two weeks – the incubation period for SARS – before being able to donate blood. The blood agency says it's a necessary precaution to deter the spread of SARS, although there's no scientific evidence that SARS can enter the blood stream.
How are patients being treated?
In Toronto, those suspected of having SARS are being quarantined in rooms with a controlled air supply, said Dr. Simor.
Anyone who goes into the room wears a special mask to filter out pathogens, as well as gloves and a gown. Hand washing is also important.
Keystone said the simple masks people are wearing in Hong Kong would stop large droplets, but masks wouldn't work against fine, aerosol droplets.
In Toronto, Simor said, patients are being treated with broad-spectrum antibiotics (in case it is caused by an as-yet unrecognized bacteria), and two antiviral drugs. One antiviral drug fights influenza and the other is a broad-spectrum antiviral that may have helped patients in Hong Kong.