Association between viral load of varicella zoster virus in cerebrospinal fluid and the clinical course of central nervous system infection

Varicella zoster virus (VZV) like other alphaherpes viruses stays latent after its primary infection. During its reactivation, it can infect the central nervous system (CNS) causing a variety of clinical presentations. Using polymerase chain reaction (PCR) for detection of VZV DNA in cerebrospinal fluid (CSF), it is now recognized in some series as the most common causative agent of viral CNS infection. We aimed to investigate in our study the correlation between VZV viral load in the CSF and the clinical course of its infection, using quantitative real-time PCR. For this purpose, we examined 56 specimens of consecutive patients with positive CSF for VZV DNA in a qualitative test, with a clinical picture of meningitis or encephalitis collected over 10 years in Rambam medical center. We found a significant correlation between VZV viral load and the severity and duration of neurological disease. We believe that using quantitative measurement of VZV DNA in the CSF, could serve as a prognostic marker which would influence treatment decisions.