In World of Warcraft, a temporary design glitch attracted the attention of psychologists and epidemiologists across North America, when the "Corrupted Blood" disease of a monster began to spread unintentionally—and uncontrollably—into the wider game world. The Centers for Disease Control intended to use the incident as a research model to chart both the progression of a disease, and the potential human response to large-scale epidemic infection. However, due to Blizzard Entertainments failure to keep statistical records of the event, the 2005 Corrupted Blood Outbreak would ultimately fail to produce any results.