Updated on Tuesday, August 21, 2007, 00:00 IST

Washington, Aug 21: A plague carried around the world by travelers, pets and curious teen-agers may show that experts have not taken everything into account when planning for an outbreak of disease, researchers said on Monday.

Luckily, the world involved is an Internet game.

The outbreak of "Corrupted Blood" indicates that specialists trying to predict what the next pandemic will look like might make use of a real-world laboratory -- the culture of online gamers.

"It really looked quite a bit like a real disease," Nina Fefferman of Princeton University, who worked on the report with her then-student Eric Lofgren, said in a telephone interview.

This includes stupid behavior, near-instant international travel and infection by pets.

The outbreak was an accidental consequence of a software challenge added to the "World of Warcraft" game in 2005, Fefferman and Lofgren report in the journal Lancet Infectious Diseases.

The virulent, contagious disease was introduced by maker Blizzard Entertainment Inc. of Irvine, California, as an extra challenge to high-level players. But, just as a real virus might spread, it was accidentally carried out of its virtual containment area.

"Soon, the disease had spread to the densely populated capital cities of the fantasy world, causing high rates of mortality and, much more importantly, the social chaos that comes from a large-scale outbreak of deadly disease," Fefferman and Lofgren wrote.

"When this accidental outbreak happened, players embraced it. Some thought it was really cool," Fefferman said.

The makers did not. They reset the computer game to eliminate the disease, wiping out any data that may have been collected.

Bureau Report