Sars virus is robust enough to survive in sewage

The virus responsible for severe acute respiratory syndrome (Sars) can survive outside the body much longer than previously thought, which could explain why it can spread so easily within a building.

Tests by the World Health Organisation (WHO) show that the virus remains stable for up to four days in the faeces of infected people with diarrhoea.

The findings could explain why more than 320 people from the Amoy Gardens apartment block in Hong Kong became infected after a man with Sars stayed there for a few days in March, a WHO spokeswoman said yesterday.

"The virus is stronger and more robust than we thought, which supports the theory that the Amoy Gardens outbreak was the result of a broken sewer line," she said. All cases of Sars apart from the Amoy Gardens outbreak appear to result from the direct transmission of the virus from one person to another. "Amoy Gardens is the only known case of environmental transmission," the WHO spokeswoman said.

Tests by WHO scientists working in Hong Kong, Japan and Germany revealed that the virus could survive in human faeces and urine at room temperature for at least two days.

But the faeces of patients with diarrhoea was slightly less acidic, which could account for why the virus could survive in it for twice as long, the scientists said.

Other tests show that the virus is easily destroyed by commonly used disinfectants. It is also easily killed at temperatures higher than 56C, although it is far more stable at room temperature than other members of the coronavirus family.

Scientists are still mystified as to the origins of the virus, although the UN Food and Agriculture Organisation in Rome said it was unlikely to have resulted from a "species jump" from domestic livestock. "There is currently no evidence for an origin in farm animals ... it seems unlikely, even if the origin of the virus is still a mystery," Peter Roeder, animal health officer at the FAO, said.

Some experts have suggested that intensive livestock production might be a breeding ground for Sars. "Intuitively one might expect this to be the case but, as there is no evidence that the virus originated in farm animals, these factors cannot be held responsible on this occasion," Mr Roeder said.

The WHO's latest figures show that there have been 6,234 cases of Sars in the world, with 435 deaths and 2,702 patients who have recovered.

Chinese authorities reported 160 new cases, bringing the total to more than 4,000 cases – about two thirds of the global total. Taiwan reported its biggest one-day increase yesterday, but in other hotspots – notably Hong Kong – the incidence continues to fall.

BEIJING LAUNCHES A PEOPLE'S WAR AGAINST THE PLAGUE

By Jasper Becker in Beijing

Do not breathe without a mask, do not kiss your children, do not have sex, do not go out to eat, shop, play or swim – and please stop blowing out the candles at birthday parties, that saliva could be deadly.

While the Beijing government is pumping its puritanical message through every possible media outlet, citizens in this plague-stricken capital are circulating their own counter-propaganda.

Drink as much baijiu – the local grain spirit brew – as possible and keep smoking. "Of course it works, and it's cheaper than medicine too," said 52-year-old Ma Dingqiao, a housewife who drinks a beaker a night.

Popular folklore holds that vinegar makes the best disinfectant and chewing or wearing garlic is the best prevention. Eating barbecued spare ribs is recommended for keeping lungs working when infected with acute respiratory diseases.

The authorities are using the heaven-sent opportunity to drive home the strictures that the masses have resisted in more than 50 years of patriotic sanitation campaigns. In this "people's war" spitting and gum chewing are out; hand-washing and assiduous disinfecting is in. After doubling the penalty for spitting in public to 100 yuan (£7.70) hygiene police are out in force watching everyone.

"Sars is a good thing to happen to Chinese people – it will teach them the merits of cleanliness and good hygiene," says Zhang Jinjie, a famous Beijing designer and owner of the Green T. House in the capital.

And of course, state health experts have been busy advising newlywed couples to postpone conceiving any babies. The last thing this government wants is for a workforce idled by Sars to start a baby-boom.