How long does herpes survive in saliva once it leaves the mouth? i have a sore on my tongue and got saliva on my hands.

Herpes? Canker?: Of course you should always wash your hands after contacting your mouth. However, a sore inside the mouth is much more likely to be a canker sore, not herpes. (Don't confuse canker sore with cold sore. Different problems, different causes.) If you do have oral herpes, it is extremely unlikely you can infect a new body area. You are immune to new infection with the same HSV type you already have.