Herpes Simplex Virus 1 (HSV-1) is mainly transmitted by oral-to-oral contact during childhood, but also sexually later in life.1 The global prevalence of HSV-1 infection is estimated to be 67%, with highest prevalence in Africa, South-East Asia and Western Pacific.1
A primary infection with HSV is often associated with the development of painful watery blisters that release an infectious exudate. Typical sites are the mouth, lips (herpes labials) or genitals (herpes genitalis).2 Recurrent skin lesions are the hallmark of HSV pathogenesis.
Orofacial herpes manifestations are usually caused by HSV-1, whereas genital herpes is mainly caused by HSV-2.2 However, the new estimates highlight that HSV-1 is also an important cause of genital herpes.2 HSV-1 and HSV-2 can also be transmitted vertically before birth or perinatally during delivery.1 Such infections may have severe, if not fatal, consequences for the fetus/newborn.1 Subclinical viral shedding and unrecognised infections seem to be major factors in transmission, therefore laboratory tests are key for a correct diagnosis.
Type-specific serologic tests for the detection of IgG, based on the use of recombinant HSV-1 glycoprotein G (gG1) and the recombinant HSV-2 glycoprotein G (gG2), allow the distinction between HSV-1 and HSV-2.3,4 This is important for a proper development of strategies to prevent transmission to partners and neonates, counselling, and management of the disease. IgM testing is not recommended in routine clinical practice.4,5,6