Maria G. Cusi, Gianni G. Savellini, Giacomo Zanelli
Department of Molecular Biology, Microbiology Section, University of Siena, Viale Bracci 1, 53100, Siena, Italy.
The Open Virology Journal, 2010, 4: 22-28
Toscana virus (TOSV) is an arthropod-borne virus which is transmitted to humans by Phlebotomus spp sandflies. Infection is the cause of brain injuries, such as aseptic meningitis and meningoencephalitis, in Italy mainly during the summer. More recently some unusual clinical manifestations due to TOSV with severe sequelae, such as ischemic complications and hydrocephalus, have been reported. TOSV represents an important emerging pathogen and its presence is being investigated in several European countries on the Mediterranean basin, including Italy, France, Spain, Portugal and Cyprus. Phylogenetic analysis has distinguished two genotypes of TOSV, A and B; the first is circulating mainly in Italy and the second in Spain, indicating a different geographic distribution possibly related to the vector. This distribution, evolving with the climate, globalization and habitat modification, has implications for the epidemiology of TOSV.
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VBORNET comment: 2010-05-01
Toscana virus (TOSV) infections account for a proportion of human aseptic meningitis cases in endemic regions, such as countries in the Mediterranean basin. Although the clinical picture is mild, with symptoms of mild meningitis, usually without encephalitic symptoms and frequent recovery without sequelae, severe outcomes, as indicated in this report, can also be observed. Turkey lies in the endemic zone for TOSV as well as other Phleboviruses and the activity of various species of Phlebotomine sandflies have been observed in Mediterranean, Aegean and Central Anatolian regions in Turkey, including P.papatasi and P.perfiliewi, well-known vector species for Sandfly Fever Phleboviruses. In Turkey, TOSV exposure in humans has been initially demonstrated by Y. Ozbel et al. (3rd Balkan Conf. of Microbiol. Sept. 2003) in the Aegean region. Recently, K. Ergunay et al. (Hacettepe University, Ankara, Turkey, submitted) revealed TOSV as well as other Sandfly Fever Virus exposure and identified cases of aseptic meningoencephalitis due to TOSV in Central Anatolia. In endemic regions, genetically divergent TOSV strains are known to co-circulate and at least two geographically distinct TOSV populations are suggested to be present in the Mediterranean basin. Based on the current data, existence of two lineages of TOSV was proposed for Spain and France. The phylogenetic analyses of the Turkish isolates displayed highest homologies to TOSV sequences from Italy and France and the Turkish TOSVs are placed in the group A of TOSV. Virus detection studies in sandflies are planned to determine the extent of TOSV and other Phlebovirus activity in Turkey.