From herpes viruses
A person can get herpes
from another person's fresh herpes sores.
The other person may have sores on his or her genitals, lips, fingers, etc..., and transmit viruses by touching the uninfected person. Sometimes, infected persons can transmit herpes even when they don't have visible fresh herpes sores, so prevention is not always possible. Most adults have had oral herpes, as it is so common.