Widespread quarantines. Bodies by the hundreds lying dead in the streets. A mass hysteria that converted once-bustling cities into ghost towns.
Such was the scenario in the fall of 2005, when a plague known as Corrupted Blood swept across the land.
Don't remember it? You might not have been logged on.
The calamity did not occur in the real world, of course. But the pandemiclike event that occurred in September 2005 in the online multiplayer realm of World of Warcraft has some researchers interested in whether such online environs could be used to predict the spread of infectious diseases in the real world.
"There are actually parallels between what would happen in the real world and what happened in this game," said Nina Fefferman, professor of applied mathematics at Rutgers University.
Fefferman is lead author of a research paper released Monday in the journal the Lancet Infectious Diseases examining the lessons of the Corrupted Blood pandemic and how they might be applied to real world disease control efforts.
"This gives us the opportunity in the future to tailor infections in the virtual world to see what would happen in the real world," she said.
World of Warcraft is a game in which players from around the world log on, interact and develop their characters in a fantasy setting. For these players, it's the ultimate in interactive recreation. But for researchers, the game holds tantalizing promise as a social model in which the conditions may be readily manipulated.
"Here, we have a large-scale computer simulation where we know everything about the disease, but its spread is determined largely by human behavior," said study co-author Eric Lofgren, a graduate student at the University of North Carolina at Chapel Hill.
"This is all free from the fact that you can't do this sort of thing in the real world because it would be horrifyingly unethical."
Some epidemiologists agreed that while the Corrupted Blood incident might not bear a direct similarity to a real-world infection, the spread of the online "disease" was an intriguing occurrence.
"I think it's interesting, and fun," said William Schaffner, chair of preventive medicine at Vanderbilt University Medical Center in Nashville, Tenn. "To the degree that any of these simulations and some of these games have utility, this can have utility also."
"We shouldn't overinterpret the results, but it is instructive to a degree."
In the time of the Corrupted Blood pandemic, the parallels, though spiked with fantasy gaming flavor, were uncanny.
As with many real-world epidemics, the symptoms of the disease were nightmarish.
"Once infected there would be an animated gush of blood," Lofgren said. "The infected character would lose health at anywhere from a trivial rate, all the way to nearly instant death if you had just started playing the game."
However, it was the fashion in which the disease was spread that many researchers find fascinating due to its similarity to potential real-world situations.
On its most basic level, being infected with the "disease" depended on your proximity to a character that was infected — and subsequently gushing diseased blood in all directions.
But as with many real-world viruses such as bird flu, the many virtual animals and pets present in the game could also act as carriers of the disease, facilitating its spread.
Travel was also an important element; though international airports are absent from the medieval setting of World of Warcraft, infected characters often "teleported" from battle areas into crowded town squares, often infecting the dozens of characters unfortunate enough to be near their points of entry.
When game developer Blizzard Entertainment Inc. of Irvine, Calif., grasped the devastating nature of the disease, it set up voluntary quarantines, which, predictably enough, were summarily violated by many, allowing the illness to spread further within the virtual realm.
"Probably the single most interesting thing for me was the player resistance to the notion of quarantine," Schaffner said, adding that the event could hold further interest for pandemic researchers due to the nature of the infection.
"This is a highly contagious infection they created," he said. "That's reminiscent of influenza."
The resulting pandemic spread, contained only by the separate servers on the game's mainframe. And though Lofgren said the event was so unexpected that an accurate account of all of the deaths could not be made, the character death toll over a few short days likely reached into the thousands.
"A lot of capital cities on servers that were infected had to be abandoned for a while," he recalled. "There were major disruptions of commerce."
"You had whole cities that essentially became uninhabitable."
Fortunately for World of Warcraft's varied populace of warriors, orcs and mages, the Corrupted Blood pandemic was short-lived — ultimately solved by a few timely lines of code and a click of the reset button to instantly resurrect all who had perished.
"We were able to fix it within a week of discovery," said a Blizzard spokesperson. "During this time, we worked closely with our community to inform them about the bug and let them know that a fix was in the works."
But Fefferman said the online realm's tragedy could be the real world's gain if such a tool could be harnessed for infectious disease research.
"That's my hope — that it will become a new framework for scientific experimentation," she said. "Without actually putting anyone in danger, we can see these behaviors occur."
Lofgren agreed. "It's a compelling idea. … A computer simulation relies on a series of assumptions. Most researchers recognize, however, that people aren't governed by a rigid set of rules."
If such a "planned pandemic" occurs, however, don't expect to see it on World of Warcraft. A Blizzard spokesperson said that there are no current plans to replicate the experience.
"Since World of Warcraft is first and foremost a game, our design decisions are determined by what will provide the most entertaining and enjoyable experiences for our players," the spokesperson said.