Sars Dna Sequenced But China Shuts Down

Researchers have begun the first close look at the molecular makeup of the Sars virus, as Beijing's usual May Day exodus of millions of travellers to and from the countryside ground to a halt yesterday.

Detailed studies of the complete DNA sequence of the virus - first recorded late last year - could speed efforts to diagnose, treat and prevent the spread of the severe acute respiratory syndrome epidemic.

Genetic studies, confirmed at high speed by a panel of experts, are to be published in the journal Science. They have already been released on the internet, but this is the first time the research has been peer-reviewed - checked by other scientists - an important safeguard in all research.

With this imprimatur, other teams can go ahead with more confidence using the DNA data

"From here, researchers should be able to target these proteins in diagnostic tests, therapies, or possibly a vaccine for Sars," said Katrina Kelner, a senior editor of Science, yesterday.

In Beijing, authorities told the population to stay at home and issued stern travel advisories to students and workers not to follow the annual custom of returning to their hometowns for the May Day holiday. Tourist agencies were told to suspend operations.

Seven new Sars deaths and 122 infections were reported in Beijing yesterday. Nationwide, 170 people have died and 3,638 have contracted the disease.

Last year, more than 87 million people hit the road in China during the May holiday.

This year's seven-day holiday has been shortened to five days. Schools, theatres and karaoke parlours have been closed. Five-lane motorways are almost deserted. On a recent drive through Beijing, the only traffic near the Forbidden City was a convoy of military vehicles, spraying disinfectant on the road in front of a giant portrait of Chairman Mao.

Beijing central station was subdued yesterday, with hundreds rather than the usual thousands waiting for trains. At a quarantine centre, masked and gowned nurses and doctors checked passengers who failed a thermal-imaging check at the station entrance.

Despite the stringent measures and fewer travellers, a nurse said the numbers of possible Sars sufferers had risen in the past two days.

"The best way to control the disease would be to stop the trains," she said. "If I had my way, that is what we would do, but the authorities have decided otherwise."

"We are leaving Beijing until Sars is under control," said one passenger. "I've never been more frightened in my life."