The main risk factor is unprotected sex with an infected individual. Asymptomatic viral shedding promotes transmission to sex partners. Vaccines are being trialled. Cell culture is slower. IF and cell culture allow typing for HSV 1 and HSV 2.
Serology is of more value for epidemiological surveys than for individual clinical diagnosis.
Histopathology Ballooning degeneration of keratinocytes and intercellular oedema lead to deep intra-epidermal vesiculation. Predominantly mononuclear infiltration, followed by influx of polymorphonuclear leucocytes. Localised necrosis and ulceration occur. Pathogenesis Direct inoculation of the virus through skin and mucous membranes results in local lesions and travel of the virus along the peripheral nerve fibres to the sacral dorsal root sensory ganglion. There the virus resides indefinitely.