Search for viruses in the CSF of patients with acute neurological disorders: possible involvement of beta-and gamma-herpesviruses

In the years 1999-2001, 868 samples of cerebrospinal fluid (CSF) from as many patients with acute neurological manifestations of suspected viral origin were analysed for the presence of viruses at the Centre for the Diagnosis of Viral Diseases of the University of Modena and Reggio Emilia. Neurological patients included 788 immunocompetent subjects and 80 patients with impaired immunity due to human immunodeficiency virus (HIV) seropositivity. Of the CSF samples, 125 (15.8%) were positive for one or more viruses among the immunocompetent patients, whereas 33 (41.1%) were positive among the HIV cohort. DNA and RNA viruses were detected in the first group of CSF samples whereas only DNA viruses were found in the second group. In immunocompetent patients the frequency of enteroviruses prevailed over that of other RNA virus families (p = 0.001) and that of herpesviruses over the frequency of other DNA virus families (p = 0.001). Among herpesvirus members, the Epstein-Barr gamma-herpesvirus prevailed on alpha-herpesviruses in each of the two groups of patients (p = 0.05 in the immunocompetent group and p = 0.006 in HIV-positive patients). The clinical relevance both of this virus and of beta-herpesviruses as a cause of neurological disorders is discussed.