Phleboviruses associated with sand flies in arid bio-geographical areas of Central Tunisia

Environmental changes following the increase in irrigated areas for agricultural in arid areas located in Central Tunisia may have led to an increase in the sand fly populations of the subgenus Larroussius and subsequently to the emergence of TOSV and other phleboviruses. [Display omitted] •Sandfly-borne phleboviruses including Toscana virus are widely distributed in Central Tunisia.•The overall infection rate of sand flies with phleboviruses was 0.12%.•The continued increase in irrigated areas in North Africa region is of high importance as it is associated with the spread of sand flies vector of phleboviruses. An entomological investigation was carried out in 2014 at two sites located in Central Tunisia, one irrigated and another non-irrigated situated in arid bio-geographical areas. Sand flies of the subgenus Larroussius namely Phlebotomus perfiliewi, Phlebotomus perniciosus, and Phlebotomus longicuspis are the most abundant sand fly species in the irrigated site. However, in the non-irrigated site, Phlebotomus papatasi of the Phlebotomus genus is the most abundant species. A total of 3191 sand flies were collected and pooled with up to 30 specimens per pool based on sex, trapping location and collection date, were tested for the presence of phleboviruses by nested reverse transcriptase polymerase chain reaction in the polymerase gene and sequenced. Of a total of 117 pools, 4 were positive, yielding a minimum infection rate of sand flies with phleboviruses of 0.12%. Phylogenetic analysis performed using partial nucleotide and amino acid sequence in the polymerase gene showed that these phleboviruses belonged to four different clusters corresponding to Toscana virus (TOSV), Saddaguia virus (SADV), Sandfly Fever Sicilian Virus (SFSV) and Utique virus (UTIV). This study provides more evidence that the abundance of P. perfiliewi is associated with the development of irrigation in arid bio-geographical areas of Central Tunisia which may have led to the emergence of phleboviruses. We report the first detection of TOSV from sand flies collected from Central Tunisia.