Genital Herpes Simplex Serology

Serology

Fifty percent to ninety percent of adults have antibody to HSV. Because of the high incidence of antibodies to herpes simplex in the population, assay of a single serum specimen is not of great value.

Subtyping.

There are two serotypes of HSV. HSV-1 infections are primarily oropharyngeal; genital infections can also be caused by this serotype.

HSV-2 infections are primarily genital but are also detected in the mouth.

HSV-1 seropositivity is usually associated with orolabial infection. Herpes simplex virus type 2 seropositivity is usually associated with genital infection. HSV-1 is now a significant cause of genital herpes and is implicated in 5% to 30% of all first-episode cases. The proportion of HSV-1 among initial genital herpes infections is higher among men who have sex with men (46.9%) than among women (21.4%) and is lowest among heterosexual men (14.6%). Receptive oral sex significantly increased the odds that initial infections are HSV-1 rather than HSV-2. Genital HSV-1 may often be acquired through contact with a partners mouth.

Type-specific Serologic Tests

Type-specific and nonspecific antibodies develop during the first several weeks following infection and persist indefinitely. Almost all HSV-2 infections are sexually acquired. Therefore HSV-2 antibody indicates anogenital infection, but the presence of HSV-1 antibody does not distinguish anogenital from orolabial infection. Persons with subclinical or unrecognized infections are best diagnosed by type-specific antibody tests.