SARS Virus Survives Outside Body For Days, Scientists Say
By Rob Stein from The Herald (Sunday, May 4, 2003)

The SARS virus can survive on common surfaces at room temperature for hours or even days, which could explain how people can catch the deadly lung infection without face-to-face contact with a sick person., scientists have found.

New laboratory studies, being released today, have produced the first scientific data on how long the SARS virus can live in various places and conditions, demonstrating for the first time that the microbe can linger outside an infected person's body.

One study showed the virus survived for at least 24 hours on a plastic surface at room temperature, which suggests it might be possible to become infected from touching a tabletop, doorknob or other object [such as a toilet seat]. Another found the microbe remained viable for as long as four days in human waste, a crucial finding that could clarify how the virus can spread through apartment buildings, hospitals and other facilities.


German scientists found that a common detergent failed to kill the virus, indicating that some efforts to sterilize contaminated areas may be ineffective.

An experiment conducted in Japan concluded that the virus could live for extended periods in the cold, suggesting it could survive the winter.

The long-awaited findings should be crucial for containing the epidemic, and they could solve one of the most important mysteries about the new disease: how the virus spreads without direct exposure to infected individuals.

"It's the first time we have hard data on the survival of the virus. Before, we were just speculating," Klaus Stohr, the World Health Organization's top SARS scientist, said Saturday. "There has been a lot of speculation that the touching of objects could be involved. This shows that transmission by contaminated hands or contaminated objects in the environment can play a role."


In addition, the findings will help researchers develop better tests for the virus and possible treatments. Now that they know what temperatures kill the virus, researchers can purify serum from sick people to use in calibrating tests and possibly to give other patients as a therapy. Serum contains antibodies that are measured by tests. In addition, the antibodies could work as a treatment if they can neutralize the virus.

The findings were produced by laboratories in Hong Kong, Japan, Germany and Beijing that are part of a scientific network organized by WHO to study the previously unknown virus. The findings were compiled and analyzed over the past few days and were to be posted on WHO's website today so public health workers aroudn the world can begin using them to keep the virus from spreading, said Stohr, who described the findings in a telephone interview.

Stohr emphasized that by far, the primary mode of transmission was through droplets that spray out when an infected person sneezes or coughs.