Co-circulation of eight different phleboviruses in sand flies collected in the Northern Apennine Mountains (Italy)

The sand flies are the biological vectors of a variety of viruses belonging to the Phlebovirus genus. As several of these viruses, like Toscana virus, are important agents of diseases in humans, the definition the phleboviruses circulating in a particular area is an important health issue. This work presents results obtained between 2013 and 2016, by testing 25,853 field-collected sand flies, sampled at 50 sites in the Northern edge of the Apennine Mountains, in Emilia-Romagna and Lombardy regions (Italy). Isolation of the three reassortant Ponticelli I, II, and III viruses was successful from five pools of sand flies. These results, and phylogenetic analysis made by obtained sequences, suggest the presence of eight different viruses: Toscana virus, Fermo-like virus, Corfou virus, Ponticelli viruses, and two unknown putative viruses. The co-circulation of different phlebovirus reported in this study, indicate a very dynamic and complex situation, which deserves a more detailed investigation to characterize their possible pathogenicity to humans and animals.