One of my generals is a one-man plague

I was finally able to attack Rome last night and captured it. There was plague when I captured it, however. After around 2 turns, the plague stopped on everybody except for my general. There were no more soldier deaths or civilian deaths, just my general having the plague. After around 2-4 turns of no plague at all in the city except him, I moved him to a navy and had him sitting by his lonesome in the middle of the sea. I must have had around 4 turns already at sea and he still has the plague and is slowly killing the navy he's sitting on. Weird.