Peril From The East

The University Of Hong Kong's pathology lab is one of the few places on earth where you can stare a newly accused murder suspect right in the face. Researchers here are using a powerful transmission electron microscope to examine a virus that was unknown to science just a month ago. This minuscule particle of protein-encrusted RNA is almost certainly the microbe that had, by last Saturday, infected more than 2,400 people in 19 countries — including 20 in Europe — and killed at least 89 since it began its rampage through the human population in China last fall. Projected onto a green phosphorescent screen by a beam of electrons and viewed through an optical device that resembles an upside-down periscope, the virus particles — this particular batch came from a relative of the Chinese doctor who became Hong Kong's first fatality on March 4 — look chillingly like aliens in a sci-fi film. "There are the little buggers," says Dr. John Nicholls, a pathologist at the University of Hong Kong, leaning aside so a Time reporter can take a look.

Magnified 100,000 times, the organisms are fuzzy little balls that fill the screen and look like the burrs that stick to your pants after a hike through the woods. You can just make out tiny hooks poking out of the spherical bodies — telltale characteristics that help classify the pathogens as members of the coronavirus family. And while coronaviruses normally cause nothing more serious than a cold, the microbes on Nicholls' slide have evidently, for reasons researchers have yet to discover, mutated into an infectious agent that has terrified the entire planet.

Since news of the first cases of SARS — short for severe acute respiratory syndrome — began emerging from mainland China a month ago, health authorities around the world have gone into high alert. For the first time in its 55-year history, the World Health Organization (who) recommended last week that travelers avoid nonessential trips to an entire region — China's Guangdong province and Hong Kong, right next door — for fear that they might contract and further spread the infectious agent.

Fear of the disease has already spread around the world. Tens of thousands of Hong Kong residents venture outdoors only with their faces covered with surgical masks. Airlines have canceled flights in and out of China and Southeast Asia, and financial losses from reductions in tourism, retail spending and other business activity could reach billions of dollars. Schools were closed across affected regions, and last week authorities in Hong Kong forced 240 people from the hard-hit Amoy Gardens apartment complex into quarantine camps outside the city. In Canada, hospitals have closed to control the disease's spread, and health officials all over the world are looking hard at anyone who flies in from Asia and quarantining those with symptoms of infection — a fever of 38°C or higher, headaches and body aches, a dry cough and shortness of breath.

Although no one in Europe or the U.S. has died from SARS and the cases have been isolated, the disease is being met with crisis measures. Hundreds of stands were left empty at BaselWorld, the world's largest watch and jewelry trade fair, after Swiss health officials barred everyone from affected Asian countries from participating. Meanwhile, U.S. President George W. Bush made SARS the first new entry to the country's list of quarantinable diseases in two decades.

All of this may seem like an overreaction to an illness that is about half as deadly as West Nile virus — SARS has killed 3.4% of its victims, compared with West Nile's mortality rate of 6.7% last year — and evidently much less contagious than measles or even the flu. "It's the type of disease that seems to require a lot of direct close contact with somebody who's pretty sick," says Dr. Stephen Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control (CDC) in Atlanta, Georgia.

But what makes SARS so frightening to scientists and the public is how much is still unknown about it, including where it came from, exactly how it spreads, how long its incubation period lasts (and thus how long a victim is contagious before symptoms appear) and whether a vaccine will ever be available. Infectious-disease specialists are haunted by the great Spanish-influenza pandemic of 1918-19; it killed fewer than 3% of its victims but infected so many that at least 20 million people died in just 18 months — more than were killed in combat in World War I. And until health officials know for sure what they're dealing with, they tend to be overcautious. "When you confront new diseases and they begin to travel widely," says who spokesman Dick Thompson, "you have to do everything you can to try to stop the transmission."