WHO announces breakthrough in SARS research

Faeces may be a more important method of spreading the SARS virus than was originally thought, the World Health Organisation (WHO) said.

Although coughing and sneezing remain the chief means of spreading the infection, research conducted by government scientists in Hong Kong has found that the virus can stay alive for at least four days in diarrhoea.

The research adds weight to the theory that leaky sewage pipes could have been a source of infection in a particularly nasty outbreak at a Hong Kong apartment complex, where more than 300 people became ill.

Dr Klaus Stohr, the WHO’s chief SARS scientist, said diarrhoea provides a more favourable environment for the virus.

Although only about 10% of people stricken with SARS get diarrhoea, the rate among patients infected in the Amoy Gardens apartment complex was 60%.

“The most exciting, or perhaps disturbing, finding is that the virus stays alive in faeces for as long as four days at room temperatures.

“That finding is the most disturbing one because it would suggest that faecal-oral transmission could take place,” said Dr Stohr, who was not directly involved in the research but coordinates the work of laboratories around the world investigating the SARS virus.

In another experiment, Hong Kong University scientists confirmed that common disinfectants can kill the virus in five minutes.

“The good news from these findings is that the virus can be relatively easily killed with common disinfectants,” he said. The Hong Kong scientists found that formaldehyde, ethanol and acetone, three common disinfectants, kill the virus.

Disinfecting toilets in hospitals and homes where people have had contact with SARS would probably solve the problem, he said.

Dr Stohr said Japanese researchers had found that the SARS virus had so far stayed alive for four days in cells on plastic surfaces at a temperature of 4 degrees Celsius (40 Fahrenheit).

“This is fridge temperature, so if someone touches something with a SARS-contaminated hand, it would stay for four days on something in the fridge,” Dr Stohr said.

The virus was also tested at minus 80 degrees Celsius (minus 112 Fahrenheit) for four days and it was unaffected. But this was no surprise, Dr Stohr said, because many viruses survive easily in cold temperatures.

It was already clear that the SARS virus can survive winter. The outbreak began in November in China and survived the winter there to spread further afield in the spring.