The Hong Kong Department of Health is opening a telephone hotline today to provide health advice on SARS (Severe Acute Respiratory Syndrome) and the World Health Organisation (WHO) has issued a rare warning of a 'global health threat', but airlines say customers are not cancelling travel plans.

The deadly pneumonia bug that has killed nine people and infected hundreds more in three continents is now thought to have reached Britain.

A man was admitted to hospital yesterday suspected of being Britain's first case of the mystery illness. He had travelled from Hong Kong to Manchester on 15 March after taking a flight from Hong Kong to Amsterdam and from Amsterdam to Manchester. Any other passengers on these flights who develop a high temperature and other flu-like symptoms are urged to contact their doctors.

The WHO has asked airlines to turn away passengers who appear to be sick.

The British Chief Medical Officer, Professor Sir Liam Donaldson, said: 'This is something we are viewing very seriously.'

The virus first emerged in China before spreading to Vietnam, Singapore, Thailand, Indonesia, the Philippines and Canada. Suspected cases have also been reported in Germany, Slovenia and now the UK. In total nearly 200 people are believed to have been infected worldwide in the last week.

The WHO has stepped up activities in response to the emergence of SARS, warning: 'The speed of international travel creates a risk of rapid spread to additional areas. Because the clinical course and epidemiological behaviour of this disease are poorly understood, WHO is calling upon national health authorities to maintain close vigilance for suspected cases.'

However, the WHO has not advised any restriction on travel.

The British government says travellers needed 'to be aware of these outbreaks and take them into account in their travel plans. However, a UK KLM spokesperson said the company has not seen reports of cancellations or a downturn in bookings.

The WHO says the disease is spread from person to person but only through close contact with a case. To date, almost all reported cases have occurred in health workers involved in the direct care of reported cases or in close contacts, such as family members: 'There is no evidence to date that the disease spreads through casual contact.' Details: The Hong Kong Department of Health hotline: 00 852 2961 8968 and www.who.int