There were a lot of debuffs that worked. The one you're talking about was probably the worst offender and we definitely spread that one when it was discovered.

It was called corrupted blood and it actually got so widespread that blizzard restarted servers to stop the spread. It came from Hakkar in ZG. We would get it on a pet and dismiss him and take it back to major cities and it would just keep spreading... Probably one of the greatest unintentional game events ive been a part of. People avoided major cities until the got under control, people would get summoned to groups with it... Madness.

ZF also had a weak debuffs that hurt other people for a while but nowhere near the level of corrupted blood, the dragon disease, or kazzak bombs.