Travellers warned to stay away from Hong Kong

For the first time in its history the World Health Organisation has advised travellers not to visit a territory because of the danger from disease.

The WHO warned yesterday that the outbreak of atypical pneumonia caused by a mystery virus which has spread around the world was still uncontrolled in Hong Kong and the neighbouring Chinese province of Guangdong.

The Foreign Office also said yesterday that it "strongly advised" people not to enter Hong Kong and Guangdong and urged people to "defer travel to areas where there is, or is thought to be, ongoing risk of infection".

The streets of Hong Kong are emptying as the population take to their homes in self-imposed quarantine against the pneumonia virus they have come to dread.

In the past few days, as the number of cases of Severe Acute Respiratory Syndrome (Sars) has mounted inexorably, the city's façade of normality has started to crack.

The government opened two more "holiday camps" yesterday for the residents of a tower block on the Amoy Gardens Estate badly hit by the virus, bringing the total to four.

The WHO defended its advice to travellers on the grounds that Sars was still spreading in the city and nine travellers from Beijing, Taiwan and Singapore had returned home with the disease after visiting Hong Kong.

But the decision will deepen the economic crisis threatening Hong Kong, which hosts 3,500 head offices for companies in the Far East. "The whole banking and financial structure rests on travel through the region," one analyst said.

The fear felt by a wide section of the population was expressed by one resident of Amoy Gardens who described how he, his wife and two school-age daughters now lead separate lives – for safety's sake. The virus is frequently transmitted within families.

"We eat in separate rooms. We do everything separately. We only take off our face masks when each of us is in a room by ourselves. My daughters are especially careful because they don't want me and my wife to get the disease," the man said.

Dr David Heymann, executive director for communicable diseases at the WHO, said the travellers from Hong Kong who developed Sars included tourists and business people who had visited the city since 15 March, when control measures against the disease were starting to work in other countries.

In Hong Kong new infections among travellers were still occurring, the latest on 25 March, which posed a risk to the rest of the world. In addition, there was the puzzle of Amoy Gardens, where more than 100 people in one tower block have been infected, which remained unexplained and suggested some new vehicle of possibly more rapid transmission.

Dr Heymann said: "We do not believe this is the air. We believe it is something else in the environment. It is possibly an object people are touching [such as lift buttons] or possibly a sewage system or water system."

He added: "This is the first time we have recommended people avoid an area and this is because we do not understand the disease completely, because there's no vaccine and no drug."

The WHO's advice to postpone travel also applies to the Guangdong province of China, across the border from Hong Kong, which declared 361 new cases of Sars and nine deaths during March yesterday.

There was widespread scepticism yesterday at the low incidence of Sars in the rest of China – no more than two dozen reported cases – and anger at the WHO's decision to impose restrictions on Hong Kong and Guangdong while allowing free movement elsewhere in the region.

The Swiss government followed the WHO's body blow with an uppercut when it announced that Hong Kong traders would be banned from the World Jewellery and Watch Fair in Basle today. Hong Kong is the largest supplier of watches in the world.

Sars has so far infected more than 2,000 people but caused just 71 deaths, raising questions as to whether it is as bad as is feared.

A British journalist who arrived in Brazil from Malaysia via Singapore to cover this weekend's Formula One Brazilian Grand Prix was under medical observation yesterday after displaying symptoms consistent with Sars.