NYTimes -- Health Organization Expanding Efforts to Find Cause of Mysterious Respiratory Illness

The agency is coordinating scientists from 11 laboratories in 10 countries to seek the cause of SARS — severe acute respiratory syndrome — which it says is a threat to world health.

Over all, the organization, an agency of the United Nations, said that there were 169 cases, including 4 deaths, reported since Feb. 1. They are from Canada, Germany, Hong Kong, Switzerland, Thailand and Vietnam.

Two features of the mysterious illness led the World Health Organization to sound an alarm last week. "One was the high degree of contagion to health care workers," Dr. Gerberding said. The extent of spread was much more "than we typically see with most infectious diseases" in the health care environment.

The second feature was the rapidity and severity with which pneumonia developed in some patients.

What has been so striking in the sketchy reports received so far is that dozens of hospital workers, ambulance drivers and visitors to hospitals have become infected from one ill patient.

This is quite troubling, unknown cause and treatment, very highly infectious, and a high degree of lethality.