Virus isolation, genetic characterization and seroprevalence of Toscana virus in Algeria

Toscana virus (TOSV; Bunyaviridae, Phlebovirus) is transmitted by sandflies of the genus Phlebotomus in the Mediterranean area. One strain of TOSV was isolated from a total of almost 23 000 sandflies collected in Kabylia, Algeria. The complete genome was sequenced, and phylogenetic studies indicated that it was most closely related with TOSV strain from Tunisia within lineage A, which also includes Italian, French and Turkish strains. A seroprevalence study performed on 370 sera collected from people living in the same area showed that almost 50% possessed neutralizing antibodies against TOSV, a rate much higher than that observed in Southern Europe. Sandfly species distribution in the study area suggests that the vector of TOSV in this region belongs to the subgenus Larroussius. These data support the rapid implementation of the diagnosis of TOSV in clinical microbiology laboratories to estimate the burden in patients presenting with neuroinvasive infections and febrile illness.