Herpes simplex virus (HSV) belongs to the α virus subfamily of the Herpesvirus and is one of the common pathogens in human viral diseases. According to the antigenicity, it can be divided into two serotypes, HSV-I and HSV-II. The clinical manifestations of the two serotypes are different.

HSV-I mainly causes infections above the waist, such as the skin and mucous membranes of the eyes, mouth, and lips, and the central nervous system. 

HSV-II mainly causes infections of the skin and mucous membranes of the genitals and neonatal infections and is related to female vulvar cancer and the occurrence of cervical cancer.