A programming oversight enabled the debuff to wow gold classic disperse beyond the site of the Hakkar boss fight and into the world at large. Hunter characters may summon and dismiss pets to fight in their side at will. Once dismissed, all the effects on the pets have been paused until it's known as back out again. In consequence, the critters could contract Corrupted Blood through the boss fight, vanish and then display the symptoms again elsewhere in the world map if they were summoned. There it might spread to other players and pets that came in contact with them.

Cities like the dwarven town Ironforge and orc city Orgrimmar were overrun within hours. Non-playable characters, who could not die due to special coding, would also catch the impact, meaning any player who passed by them could get Corrupted Blood.

After word got out, players searched frantically for information about what was going on.

"We kept a close attention not just on our guild conversation but on world chat too to see where not to go. We didn't want to catch it."

The spread of Corrupted Blood, and cheap classic wow gold also the participant's behavioral changes to it, captured the interest of epidemiologist Dr. Nina Fefferman, who was a World of Warcraft player in the time of this episode. Fefferman reached out to her colleague Dr. Eric Lofgren. In 2007, the two published a paper that detailed their findings, such as complicated models of human behavior during a pandemic. Fefferman says the incident has helped inform her current research into predictive modeling around covid-19.