viruses Article Circulation of Toscana Virus in a Sample Population of Corsica, France Shirley Masse 1, * , † , Nazli Ayhan 2, † , Lisandru Capai 1 , Frédéric Bosseur 3 , Xavier de Lamballerie 2 ,Rémi Charrel 2 and Alessandra Falchi 1 1 Université de Corse Pascal Paoli, EA7310 BIOSCOPE, 20250 Corte, France 2 Unité des Virus Emergents (UVE: Aix Marseille Univ, IRD 190, INSERM 1207, IHU Méditerranée Infection), 13385 Marseille, France 3 Sciences Pour l’Environnement—UMR CNRS 6134, Université de Corse, 20250 Corte, France * Correspondence: masse_s@univ-corse.fr; Tel.: +33-420-202-219; Fax: +33-420-202-392 † These authors contributed equally to this work. Received: 12 August 2019; Accepted: 31 August 2019; Published: 4 September 2019   Abstract: Sandfly-borne phleboviruses pathogenic to humans, such as Toscana virus (TOSV) and Sandfly Fever Sicilian virus (SFSV), are endemic in the Mediterranean region. In France, several autochthonous cases of TOSV infection have been described, causing either meningitis or encephalitis. The aim of the present study was to investigate the seroprevalence of TOSV and SFSV antibodies in a healthy population from Corsica. In this cross-sectional study, participants were enrolled (i) from a medical staff at the University of Corsica and (ii) from general practitioners of the Corsican Sentinelles Network. The seroprevalence study was based on a virus microneutralization assay. A total of 240 sera were tested. Altogether, 54 sera (22.5%) were confirmed positive for TOSV antibodies, whereas none were positive for SFSV (0/240). The residential district of participants was significantly associated with TOSV seropositivity (p value = 0.005). The rate of the seropositivity against TOSV in our study suggests that the Corsican population is well exposed to the TOSV. These results encourage the implementation of a systematic surveillance system including entomological, microbiological, and medical aspects for the collection of better information on the diseases that are associated with phleboviruses in Corsica and beyond in the regions where these viruses are present. Keywords: Sandfly Fever Sicilian virus; seroprevalence; microneutralization; meningitis; arbovirus; arthropod-borne virus; Phlebovirus; Phenuiviridae; Bunyavirales; sandfly 1. Introduction Sandfly-borne phleboviruses pathogenic to humans such as Toscana virus (TOSV) and Sandfly Fever Sicilian virus (SFSV) are endemic in the Mediterranean region [1,2]. Although most human infections are either asymptomatic or influenza-like syndromes, TOSV has emerged as outbreaks and sporadic cases of acute meningitis or meningoencephalitis. TOSV human cases have been reported in southern European countries such as Italy, Spain, Greece, Portugal, and France, including most of the Mediterranean islands [3]. SFSV frequently causes epidemics of febrile illness during the warm seasons [1] and is not neurotropic [4]. In France, the first case of TOSV infection was reported in a German tourist returning from the region of Marseille in southeastern France [5]. Since then, several autochthonous cases of TOSV infection in France have been described, causing either meningitis [6] or encephalitis [7]. Furthermore, myositis was reported as an additional clinical complication of TOSV infection [8]. Concerning SFSV, low seroprevalence rates of SFSV antibodies were recorded in southwestern France (2%) and in Marseille (1%) among blood donors [9]. Viruses 2019, 11, 817; doi:10.3390/v11090817 www.mdpi.com/journal/viruses