Diagnosis of neurological herpesvirus infections: Real time PCR in cerebral spinal fluid analysis

Human herpesviruses (HHVs) cause many serious acute and persistent central nervous system (CNS) disorders. Because these infections manifest with various, often non-specific, symptoms and signs, and because specific therapy is often available, accurate diagnosis is essential. Cerebrospinal fluid (CSF) from 146 patients with acute meningitis or meningoencephalitis and 9 with "other neurological disorders" were analyzed by using an automatic system for nucleic acid extraction and quantitative real-time polymerase chain reaction (PCR) for herpes simplex 1 and 2 (HSV-1, HSV-2), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), herpesvirus-6 (HHV-6), and varicella-zoster virus (VZV). HHVs DNA was detected in 52 of 155 (33.5%) analyzed samples. In 39 CSF samples from patients with meningoencephalitis we found: VZV in 13, HSV-1 in 12, EBV in 6, HHV-6 in 4, and HSV-2 in 4. Co-infections of EBV and HSV2, HSV-I and HSV-2, HSV-1 and VZV were also disclosed in four cases. In addition, two patients with Guillain-Barré syndrome had HCMV and one showed HHV6 positivity, two patients with myelitis / polymyeloradiculitis had VZV and HCMV respectively, HHV-6 DNA was found in one patient with lateral amyotrophic sclerosis. Three CSF specimens from HIV-infected patients with CNS complications had HHV-6 or EBV DNA. Moreover quantitative data were also correlated to clinical conditions to obtain more information on the virus aetiopathogenic role.