Incidence and clinical features of herpes simplex viruses (1 and 2) and varicella-zoster virus infections in an adult Korean population with aseptic meningitis or encephalitis

Since there are limited data on the incidence and clinical findings of central nervous system (CNS) infection by three α-herpesviruses including human herpes simplex virus 1 (HSV-1), HSV-2 and varicella-zoster virus (VZV) in Korea, a retrospective analysis of clinical data and polymerase chain reaction (PCR) results was performed in patients who presented with suspicion of acute viral meningitis and/or encephalitis at the emergency department of a tertiary referral hospital in Seoul, Korea. During the 3-year study period, a total of 224 cerebrospinal fluid (CSF) samples from 224 patients were examined. Among the 224 patients, 135 (60.3%) patients were identified as having aseptic meningitis (n=70, 51.9%), encephalitis (n=41, 30.4%) or meningoencephalitis (n=24, 17.8%) at discharge. Twenty-four (17.8%) patients were identified as having VZV meningitis (n=16, 11.9%), VZV meningoencephalitis (n=2, 1.5%), HSV-2 meningitis (n=4, 3.0%), or HSV-1 encephalitis (n=2, 1.5%). Of the 24 patients infected with the three herpesviruses, immunocompromised patients accounted for 33.3% (n=8). Skin rashes were observed in half (n=9) of the patients with VZV, and none with HSV-1 or HSV-2. One patient with VZV meningitis and four patients with brain parenchymal involvement had neurologic sequelae. In conclusion, three herpesviruses are important causative agents of CNS infectious disease with significant morbidity in adults, regardless of the immunologic status. Therefore, CSF should be examined for HSV-1, HSV-2, and VZV using sensitive diagnostic methods in all cases of adult patients with clinical manifestations of CNS disease in order to identify the correct etiology and to determine appropriate therapy.