Some of the starkest early reports about the deadly SARS pneumonia came not from health authorities, but from Internet discussions in which emergency-room physicians swapped details about the start of the epidemic

An intensive-care specialist at a hospital in Hong Kong, a community virtually shuttered by the virus, riveted his colleagues with dispatches from the SARS, or Severe Acute Respiratory Syndrome, front lines. "There are now 145 confirmed cases in the Prince of Wales Hospital," Tom Buckley wrote in an e-mail message last month. "New cases (first contact) tend to bring their families (second contact). Close family contacts seem to have a very high rate of infectivity. The outbreak within the hospital appears to have been contained, but it has put an enormous strain on the system." At a time when the world was paying far more attention to the war on Iraq than to a still-mysterious disease, these notes stand out as a prescient warning about the risks of SARS, a contagious lung infection with a fatality rate of about 5 percent. As of that date, Hong Kong authorities had reported more than 260 cases of SARS, including 10 deaths. By this week, Hong Kong's total had ballooned to 1,232 cases and 56 deaths. Meanwhile, economists lopped a few percentage points off their Asia GDP forecasts, Intel and Hewlett-Packard temporarily closed their Hong Kong offices, and business and tourist travel to the area has plummeted. The World Health Organization has responded to the threat of SARS by using its Web site to publish daily updates about the number of worldwide cases--which has allowed analysts to graph the progress of the outbreak.