Evidence of Toscana virus infections without central nervous system involvement: a serological study.

In central Italy, acute lymphocytic meningitis and meningoencephalitis due to a Phlebotomus transmitted virus (Phlebovirus Toscana, TOSv) occurring throughout the summer are frequently observed. Several serum specimens of patients hospitalized with a clinical picture of viral meningitis/meningoencephalitis showed anti TOS-IgG reactivity suggestive of a previous infection occurring at an unknown time in the past. This observation led us to design a serological investigation of 83 household contacts of 46 summertime CNS infection patients (index cases) with the purpose of evaluating the percentage of both IgG and IgM in seropositive healthy individuals, living, like the index cases, in areas at high risk of phlebotomine sandfly bites.