The World Health Organization expert who first identified the mystery pneumonia that has claimed dozens of lives has himself died of the disease, the UN agency has announced.
Many people are buying surgical masks
Dr Carlo Urbani, a 46-year-old Italian and an expert on communicable diseases, had identified Severe Acute Respiratory Syndrome (SARS) in an American businessman admitted to hospital in Vietnam in February.
The WHO said Dr Urbani's early detection of SARS had led to increased global surveillance, enabling the identification and the subsequent isolation of those with the disease to slow its spread.
At least 54 people are known to have died of the disease, and more than 1,400 people to be suffering from it.
Hong Kong, where it is believed the disease first broke out, reported 60 fresh cases of infection on Saturday.
The government has decided to close the city's schools for a week, while thousands of people are wearing surgical masks when they leave their houses.
Because of Dr Urbani's early detection of SARS, global surveillance was heightened and many new cases have been identified
Hong Kong's health secretary said more people would fall ill, despite the fact that more than 1,000 people had already been quarantined.
Hong Kong, Taiwan and Singapore are all confining people to their homes if they have been exposed to the disease.
Isolated cases have been identified in Europe and North America.
However in China, where the outbreak has killed at least 30 people, the communist regime is enforcing a media blackout, apparently concerned that news of the disease will cause panic.
Chinese authorities have come under widespread fire for their secretive handling of SARS.
They have continued to stall on granting permission for a group of WHO doctors to visit the south of the country, where China's first cases of the virus appeared.