Phlebotomus-transmitted toscana virus infections of the central nervous system: A seven-year experience in Tuscany

Toscana virus (TOSv) is a recently discovered Phlebotomus-transmitted human pathogen involved in acute infections of the central nervous system (CNS) occurring during the summer in natural foci in Italy. The purpose of this p rospective study was to investigate the role of this virus in 170 patients with meningitis-meningoencephalitis of suspected viral origin, admitted to the Departments of Infectious Diseases at the Siena Hospital from 1990 to 1 996, Infections caused by tick-borne encephalitis virus (TBEv) and TOSv or other neurotropic viruses were routinely diagnosed by means of conventional virological methods. 89 cases were attributed to TOSv, about 10% of which were Europeans on vacation in Tuscany. All of the TOSv-positive cases mere observed during the summer and mere residents of hilly areas in Siena and i ts province at an altitude not above 500 m, An increase in the number of ca ses was observed over the years, with a higher incidence among younger peop le. The clinical picture was similar to that observed in other viral infect ions of the CNS. Evolution was benign in all cases; in 2 subjects symptoms and signs of encephalitis were present.