Oral herpes is contagious and is caused by infection with the human herpes simplex virus, which can be found in the blistering fluid and saliva of patients, recovering patients, or asymptomatic persons with the virus. Transmission is mainly through direct contact, but also through indirect contact. Direct contact transmission can be by endogenous self-inoculation, for example, herpes simplex virus infection can be caused by biting the nails or sucking the thumbs. It can also be exogenous inoculation, such as when a health care worker comes in contact with a skin lesion, which can cause hand infection. There is also indirect contact transmission, mainly through saliva, etc. Although the saliva and secretions of asymptomatic carriers contain very low levels of virus, it is a major source of infection that can cause indirect contact. Therefore, it is important to avoid contact with patients with this virus in order to avoid causing herpes orofacialis.