HSV-2 meningoencephalitis in an immunocompetent young man: what is the pathogenesis and what is the treatment?

Herpes simplex encephalitis is rarely caused by herpes simplex virus type 2 (HSV-2) after the neonatal period. The pathogenesis of HSV-2 encephalitis is not known and its treatment has not been discussed. We report a case of mild meningoencephalitis secondary to HSV-2 primary infection after sexual risk behaviour in a healthy young man. The diagnosis was established upon clinical, biological and electroencephalographic criteria. Aciclovir treatment led to rapid clinical improvement. This case highlights HSV-2 as a rare cause of meningoencephalitis, and questions the management of this rare manifestation of HSV-2 infection.