How does the SARS virus spread?

The answer is D. Recent studies show that the SARS virus can spread not just by physical contact with an infected person, but also by touching surfaces touched by an infected person and even when proper hygiene is not maintained.

Initially, health researchers working on the virus believed that SARS was transmitted through droplets that spray out when an infected person sneezes or coughs. However, they began to suspect that there were other ways by which the virus was spreading when some people became infected without having had close contact with a sick person.

The reason the SARS virus gets transmitted even without physical contact is that it can survive outside an infected person at room temperature for hours or even days. One study showed that the virus can survive for at least 24 hours on a plastic surface at room temperature. This means that if an infected person who touches a table or a doorknob leaves the virus there, another person touching those objects for the next 24 hours could be infected. Another study found that the microbe lived for as long as four days in human waste.

Common detergents are ineffective in killing the virus, so better methods of sterilizing contaminated areas are required. The virus has even been found to live for extended periods in the cold.

On the brighter side, however, now that researchers know how long the virus survives outside an infected person, they will be able to design more efficient ways to stop its spread.

Resources:

Frequently asked questions about SARS.

Further information on SARS.

Learn about quarantine and other measures taken against SARS.

June 14, 2003