The agency has declared the condition a "worldwide health threat."

The W.H.O., an agency of the United Nations, on Saturday declared the ailment "a worldwide health threat."

Leading virology laboratories that usually are competitive have been cooperating in response to W.H.O.'s declaration that the disease was "a worldwide health threat."

The W.H.O., a United Nations agency, has declared the illness - known as severe acute respiratory syndrome - a "worldwide health threat."

Less than four weeks have passed since W.H.O. first recognized SARS and declared it "a worldwide health threat."

In declaring SARS "a worldwide health threat" on March 15, W.H.O. officials said they knew the announcement would have severe economic consequences.

The rest of the world did not know about SARS until March 15, when the W.H.O. issued an alert, calling the disease a "worldwide health threat."

Mr. Thompson ordered the daily briefings on March 15, the day the World Health Organization declared SARS a "worldwide health threat."

W.H.O., which is the lead agency investigating SARS, has declared it "a worldwide health threat" and says scientists are edging closer to finding a virus as its cause.

Spread of a mysterious respiratory illness to a number of Asian countries and Canada has led the World Health Organization to declare it "a worldwide health threat" - but little is known about the ailment.

A Presumption of Quarantine It was in March that the World Health Organization issued an alert calling SARS a "worldwide health threat" and intense news coverage of the disease began.

The events justify the bold alarm that the World Health Organization set off on March 15 when it declared SARS "a worldwide health threat," at a time when cases and deaths were few in number.

As a mysterious respiratory illness spread to more countries, the World Health Organization yesterday issued a rare health alert, declaring the ailment "a worldwide health threat" and urging all countries to help in seeking its cause and control.

The W.H.O. declared that SARS was "a worldwide health threat," activated its global monitoring system, and deliberately chose a name that would not offend any group as the early names for AIDS did.

The 3 laboratories are part of a network of 11 labs in 9 countries that the W.H.O. has created to find the cause of the ailment, which the agency, a unit of the United Nations, has declared "a worldwide health threat."

Leading virology laboratories around the world, which are usually competitive and do not share information until they report their findings at scientific meetings or in journals, have been cooperating in a manner unrivaled in the past in response to the World Health Organization's declaration that the disease was "a worldwide health threat."