Online 'blood plague' offers lessons for pandemics

In web forums, players described scenes of devastation. One said the online world had been "filled to the brim with corpses."

"The city had streets literally white with the bones of the dead," the player said. Screenshots show game characters walking through eerily deserted streets strewn with skeletons.

"Seemingly innocuous aspects of the game world, each directly mirroring an aspect of real-world epidemiology, allowed what should have been a very minor point of interest in a small area of the game... to become the first online instance of uncontrolled plague to affect millions of Americans, Asians and Europeans at home," Fefferman and Lofgren wrote.

HUMAN RESPONSES

What made Corrupted Blood so interesting was the way players responded -- providing an insight into the psychological response to plague that most computer models can never hope to capture.

Some players selflessly rushed to help, using their healing powers and acting as first responders despite the risk.

"Their behavior may have actually extended the course of the epidemic and altered its dynamics... keeping infected individuals alive long enough for them to continue spreading the disease, and by becoming infected themselves and being highly contagious when they rushed to another area," the Lancet article said.

Others got infected on purpose and strolled around populated areas -- leading some security analysts to say the incident may provide insight into how terrorists would exploit a pandemic.

Dealing with thousands of complaints from players whose online alter egos had fallen victim to the plague, Blizzard Entertainment tried to quarantine the infected zones. But -- as is likely in real life -- the barriers were porous and some infected victims managed to find their way into "safe" areas.