Detection of neurotropic viruses circulating in Tuscany: the incisive role of Toscana virus.

Acute meningitis is perhaps the most frequent among central nervous system infections. We report a study considering 277 cases of meningitis hospitalized in the southern Tuscany area (Italy) during the period from 1995 to 1998 investigated by tissue culture and polymerase chain reaction (PCR) methods. The cytochemical analysis of the cerebrospinal fluid samples suggested the diagnosis of aseptic meningitis, recognized as viral meningitis in 104 cases by detection of viral DNA or RNA. The results collected by tissue culture technique, available for 95 clinical samples, reported a positive isolation for only 12 cases. The viruses identified in the neurological infection were Toscana virus (81%), enterovirus (12%), mumps virus (3%), measles virus (1%), and herpes virus type 1 (3%). These data demonstrate the incisive role of the RNA viruses as the cause of meningitis, and overall the relevance of Toscana virus.