General Exalted Discussion XVII: Edition of Cascading Years

[TheCountAlucard]

So, for my seafaring game, the group intends to sabotage a number of Realm warships via having the group's Abyssal sneak onboard and use her ability to bestow disease with a touch to cripple their crews. Only thing is, the fleet's docked at a port at the moment and if they get sick it'll probably spread to the port city.

Any suggestions for a disease that's contagious enough and incapacitating enough to hinder the crews, but not fast-acting enough to give the fleet time to launch first?