Recurrent viral meningitis Recurrent viral meningitis is most often due to Herpes simplex virus type 2 (HSV-2; called Mollaret meningitis) Typically when HSV-2 is the cause, patients have ≥ 3 episodes of fever, nuchal rigidity, and cerebrospinal fluid (CSF) lymphocytic pleocytosis; each episode lasts from 2 to 5 days, then resolves spontaneously.