Detection of human herpesviruses in cerebrospinal fluids collected from patients suspected of neuroinfectious diseases

The full spectrum of human herpesviruses (HHV)-associated neuroinfectious diseases in immunocompetent adults remains unclear. Hence, we sought to elucidate the epidemiology and clinical features of these diseases. The study subjects were patients over 16 years old suspected of neuroinfectious diseases who underwent spinal tap performed by neurologists in our university hospital between April 2013 and March 2018. The presence of seven HHV DNAs in cerebrospinal fluid (CSF) was determined by real-time PCR. HHV DNAs were detected in 33 (10.2%) of the 322 patients. The most frequently detected herpesvirus was varicella zoster virus (VZV) (19 patients), followed by HHV-6 (four patients), herpes simplex virus (HSV)-1 (three patients), HSV-2 (three patients), and Epstein-Barr virus (two patients). HHV DNAs were detected in CSF collected from patients with various neuroinfectious diseases, including myelitis, peripheral neuritis, encephalitis, and meningitis. All patients with HSV-1 DNA had encephalitis, whereas all patients with HSV-2 DNA had meningitis. Eleven of the 19 patients with VZV DNA had meningitis. Patients with VZV-associated encephalitis (median age, 80 years) were significantly older than non-encephalitis patients (median age, 60.5 years) (P = 0.046). Although post-herpetic neuralgia was observed in seven (54%) of the 13 patients with VZV and without encephalitis, no such neurological sequela was observed in the four encephalitis patients. In conclusion, HHVs were associated with approximately 10% of neuroinfectious diseases in this cohort. VZV was the most common pathogen, probably due to the large number of VZV meningitis patients. In addition, patients with VZV-associated meningitis were significantly younger than patients with VZV-associated encephalitis.