Happened on WoW (2005) : An epidemy was brought through a glitch by some players, causing

Epidemic is correct. For those not aware and for more detail: there was a quest wherein part of the quest was a deadly plague spell held by a boss. The programmers didn’t intend players to be able to leave the area with the plague- it was just a spell passed by proximity. What they did not do was consider in WOW, players can have pets that follow them- and can teleport. The programmers not only made it so pets could be infected- they failed to make it so the pets couldn’t spread the plague. Some people did it on accident- but once certain players found out they deliberately infected or failed to mark themselves as infected and used themselves to spread the virus. In the end the servers needed to be reset.

Actually it spread through the Hunter's pets. They have pets on the game that any person can have and then they have hunters that have pets that hunt and fight with them.
See the pets could get sick because they would battle the bad guys as well and then people would pocket their pet, leave the area, and then when they pulled the pet back out the pet was still sick and it would end up killing a lot of people. Now I didn't do this in any large area but I did do it in a small area. Lmfao it was only to see if it really does work. There was a shitload of people cussing and swearing lol

Lmao. Thank you for the clarification- and as always a good story!