Etiology of aseptic meningitis and clinical characteristics in immune-competent adults.

Viral meningitis is the most common cause of aseptic meningitis. Use of the polymerase chain reaction (PCR) has increased the ability to determine the etiology of viral meningitis. This study used PCR analysis to evaluate the etiology of aseptic meningitis in 177 previously healthy adults over a 5-year period, as well as analyzing the clinical characteristics, cerebrospinal fluid (CSF) findings, and prognosis according to each etiology. The most frequent cause of aseptic meningitis was enterovirus (EV), followed by varicella zoster virus (VZV). Patients with EV meningitis were significantly younger than those with VZV meningitis. The percentage of lymphocytes in white blood cell counts and protein concentrations in the CSF differed significantly among patients with EV, VZV and meningitis of undetermined etiology. Younger age and lower percentage of lymphocyte and protein level in CSF analysis may be suggestive of EV meningitis. Further prospective studies are warranted to identify the correlations between the clinical characteristics and the etiologies of meningitis.