What effect do mice droppings and/or urine have on human health?

My grandfather is quite old, and lives in a house which has a slight mice problem. Since he is often sick, i am wondering, do the mice have anything to do with it or do they contribute to his poor health in any way?What effect do mice droppings and/or urine have on human health?
Mice are the worst vectors for most infectious diseases. You need to get rid of the mice even if they aren't making your grandfather sick. Try laying out traps that catch them if you don't want them killed but they really don't belong in anyones household. They chew wires and when they do poo and urinate on things, if you don't know it and that thing ends up in your mouth, like on a soda can, you can get really sick or possibly die from that. I forgot what diseas it was exactly but mice are no good.What effect do mice droppings and/or urine have on human health?
I'm not sure if it's true or not since i got it in an e-mail, but i read it can make you really sick (can't remember if it kills you, but don't risk it) just in case, see if you can get rid of the mice