SARS

What is SARS?

Severe acute respiratory syndrome, commonly known as SARS, is an infectious viral disease. The virus is spread mainly through sneezes and coughs (airborne or droplet transmission) and infects the respiratory tract.

The SARS virus first emerged in late 2002 in Guangdong, China, causing a large-scale outbreak that resulted in hundreds of deaths. ^{[1] [2]} The outbreak was finally contained after a successful international effort (see Epidemiology, below).

Epidemiology

The SARS virus most likely originated in bats and passed to humans through civet cats (small mammals native to tropical Asia and Africa). It is thought the virus moved from civet cats to humans in 'exotic meat' markets, where live wild animals are sold.

The SARS virus first emerged in late 2002 in Guangdong, China. It spread rapidly across the world, reaching 28 countries, causing 8,098 people to fall ill (20% of them were healthcare workers). ^{[1] [3]} Of these people, 774 died. People over 65 years old were severely affected, with a 50% mortality rate in that age group. ^{[3] [4]}

A global health alert was announced in early 2003 and a large-scale international effort to contain the virus followed. Because regular infection control methods failed to prevent the spread of the virus, people with SARS had to be quarantined for the duration of the disease. Travel restrictions were also put into place.

The epidemic finally ended in July 2003. There have been no known cases of SARS since early 2004. The SARS epidemic had demonstrated that the world in the 21^st century is truly a 'global village'. International travel is common and can lead to infectious disease spreading quickly across the world. This realization led to the adoption of the International Health Regulations (IHR) in 2005, a legally-binding agreement that coordinates the global response to infectious epidemics.

Causes

The cause of SARS is the SARS coronavirus (SARS-CoV). This virus belongs to the coronavirus family, which also includes the virus that causes Middle East respiratory syndrome (MERS). When the SARS virus enters the lungs, it can damage lung cells and cause inflammation.

When an infected person sneezes or coughs, the SARS virus spreads into the air via millions of tiny droplets, each containing many viruses. If a droplet enters your nose or mouth, you may then become infected. The droplets can also collect on surfaces and objects, so you can also catch the virus by touching an infected surface and then touching your nose or mouth area. The SARS virus can also pass from person to person via the fecal-oral route.

Signs and symptoms

Signs and symptoms of SARS resemble those of influenza and other viral illnesses, and include:

• Fever;
• Sore throat;
• Dry cough;
• Breathing difficulties;
• Discomfort (malaise);
• Headache;
• Chills;
• Dizziness;
• Stiff muscles;
• Diarrhea;
• Loss of appetite, and;
• Runny nose.

Not everyone who is infected with the virus will fall ill. The virus's incubation period is usually between two and seven days.

Methods for diagnosis

SARS can not be diagnosed by its symptoms alone. Your doctor will need to take nasal swabs, a blood sample or a stool sample from you and send it to a specialized laboratory for testing. Since SARS is a highly infectious disease and a high-level public threat, SARS tests are often high priority. Your doctor may also wish to have a chest X-ray taken.

Types of treatment

There is no specific treatment for SARS. A person suspected of being infected will be quarantined to prevent further spread, and can receive supportive treatment if necessary, which may include:

• Breathing support (a ventilator);
• Antiviral medication;
• Antibiotic medication for treating secondary bacterial infections (usually pneumonia), and;
• Anti-inflammatory medication.

Prognosis

Most people recover completely from SARS after a few weeks.

Prevention

There are currently no specific vaccines or antiviral medications to protect against SARS. You can prevent SARS from spreading by practicing good hygiene measures, such as:

• Avoiding contact with others;
• Covering your mouth and nose when sneezing;
• Washing your hands thoroughly;
• Cleaning your surroundings;
• Being alert about the risk of infection. Consult your doctor if you have any concerns, and;
• If you think you may have SARS, call ahead to your health facility to discuss infection control measures such as wearing a facemask to reduce potential spread and to allow the health facility to adequately prepare for your arrival.

References

1. Graham, R.L., Donaldson, E.F. & Baric, R.S. (2013) A decade after SARS: strategies for controlling emerging coronaviruses. Nature Reviews Microbiology 11:836–848.
2. Groneberg, D.A., Hilgenfeld, R. & Zabel, P. (2005) Molecular mechanisms of severe acute respiratory syndrome (SARS). Respiratory Research 6:8-24.
3. Madigan, M.T., Martinko, J.M., Bender, K.S., Buckley, D.H. and Stahl, D.A. Brock Biology of Microorganisms (14th global edition). Boston, US: Benjamin Cummins.
4. Severe acute respiratory syndrome (SARS). Centers for Disease Control and Prevention. Accessed 6 March 2015, from link here
5. CDC - SARS - Severe Acute Respiratory Syndrome. Accessed 10 September 2014 from link here
6. Choices N.H.S. (2013 May 30). SARS (severe acute respiratory syndrome) - NHS Choices. Accessed 10 September 2014 from link here
7. Coronavirus Infections. Text. Accessed 10 September 2014 from link here
8. Cunha C.B. & Opal S.M. (2014). Middle East respiratory syndrome (MERS): A new zoonotic viral pneumonia. Virulence 5: 650654.
9. Graham R.L. Donaldson E.F. & Baric R.S. (2013). A decade after SARS: strategies for controlling emerging coronaviruses. Nature Reviews Microbiology 11: 836848.
10. Groneberg D.A. Hilgenfeld R. & Zabel P. (2005). Molecular mechanisms of severe acute respiratory syndrome (SARS). Respiratory Research 6: 8.
11. Hilgenfeld R. & Peiris M. (2013). From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses. Antiviral Research 100: 286295.
12. Michael T. Madigan John M. Martinko Kelly S. Bender Daniel H. Buckley David A. Stahl. Brock Biology of Microorganisms (14th ed.). Benjamin Cummins.
13. SARS: systematic review of treatment effects - National Library of Medicine - PubMed Health. Accessed 10 September 2014 from link here
14. SARS: What have we learned? (2003). Nature 424: 121126.
15. Severe acute respiratory syndrome (SARS). (-a). Accessed 10 September 2014 from link here
16. Severe acute respiratory syndrome (SARS). (-b). Better Health Channel. Accessed 10 September 2014 from link here
17. Severe acute respiratory syndrome (SARS) - Blue Book - Department of Health Victoria Australia. instructional. Accessed 10 September 2014 from link here
18. Severe Acute Respiratory Syndrome (SARS) | Johns Hopkins Medicine Health Library. Accessed 10 September 2014 from link here
19. Severe Acute Respiratory Syndrome (SARS) Coronavirus Research NIAID NIH. Accessed 10 September 2014 from link here
20. WHO | Severe acute respiratory syndrome. WHO. Accessed 10 September 2014 from link here

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