The initial detection of Toscana virus in phlebotomine sandflies from Turkey

Abstract

Toscana virus (TOSV) is a prominent arthropod-borne viral agent of human central nervous system infections occurring in the Mediterranean region. The main transmission route to susceptible individuals involves sandflies as vectors. Despite several reports revealing widespread TOSV activity in Turkey, vectors remained unidentified. A sandfly field survey was carried out in five provinces in Central, Southeast and Mediterranean Anatolia in 2017 to identify TOSV and related sandfly-borne phleboviruses and Leishmania parasites, with evidence for circulation in the region. A total of 7136 sandfly specimens, collected via standard methods, were evaluated in 163 pools. TOSV was detected in 11 pools (6.7%), comprising Phlebotomus major sensu lato, Sergentomyia dentata and Phlebotomus papatasi species. TOSV partial L and S segment sequences were characterized, that phylogenetically clustered with local and global genotype A strains. An amino acid substitution outside the conserved motifs of the viral polymerase, also present in previous TOSV sequences in endemic regions, was observed. Leishmania tropica was detected in a single pool of Ph. sergentii (0.6%). This is the first report of TOSV in sandflies from Turkey, and this study further provides evidence for additional sandfly species with the potential to transmit TOSV.

The current epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia and implications for disease emergence in European countries

“…infection rates in sand flies analysed individually ranged between 0% and 1.96% (Table 3) (Bolukbas et al, 2016; Özbel et al, 2016; Svobodová et al, 2009; Töz et al, 2009). Similarly, minimum infection rates in pooled sand fly samples were between 0.63% and 5.17% (Demir & Karakuş, 2015; Karakuş, Arserim, et al, 2019; Karakuş et al, 2017; Kavur et al, 2018; Kavur et al, 2015; Özbel et al, 2020).…”

Comprehensive Cross-Sectional Evaluation of Human Sandfly-Borne Phlebovirus Exposure in an Endemic Region

“…However, the relationship between phleboviruses and vectors does not seem exclusive, and identical phleboviruses can be identified within several sandfly species [ 3 ]. Interestingly, in the only available vector screening effort with TOSV detection from Turkey, virus sequences were identified in Phlebotomus papatasi , Phlebotomus major complex, and Sergentomyia dentata species [ 23 ]. The sandflies belonging in the Phlebotomus major complex were also documented as the main vector for SFTV, the regional SFSV variant in Anatolia [ 24 ].…”

First report of Karimabad virus in Rhombomys opimus in China

“…The genus Phlebovirus of the Phenuviridae Family (order Bunyavirales ) contained a group of pathogens associated with human diseases with severe public health concern [ 1 ]. According to the most recent classification of the International Committee on Taxonomy of Viruses (ICTV), 66 viral species had been grouped into the genus Phlebovirus [ 2 ], which were widely distributed in tropical areas of the New World and semi-arid and temperate areas of the Old World, including southern, southeastern and central Europe, Africa, central and western Asia [ 2 , 3 ]. The predominant part of known phleboviruses is transmitted by sandfly, while a few others are transmitted by mosquitoes (e.g., Rift Valley fever virus, Gouleak virus) and ticks (e.g., Mukawa virus) [ 4 ].…”