As posted by someone on fextralife on Infect's page:

"This Skill appears to be bugged. If you Infect an enemy who has previously had damage dealt directly to his Vitality/Health bar, he will actually REGAIN HP up to the new maximum amount of Vitality that is determined by his reduced Constitution level set by the Diseased Status."

EDIT: wow. Just wow.

Last edited by Try2Handing; 02/12/17 02:25 AM. Reason: to add EDIT
"We make our choices and take what comes and the rest is void."