Isolation, genetic characterization, and seroprevalence of Adana virus, a novel phlebovirus belonging to the Salehabad virus complex, in Turkey

Abstract

A new phlebovirus, Adana virus, was isolated from a pool of Phlebotomus spp. (Diptera; Psychodidae) in the province of Adana, in the Mediterranean region of Turkey. Genetic analysis based on complete coding of genomic sequences indicated that Adana virus belongs to the Salehabad virus species of the genus Phlebovirus in the family Bunyaviridae. Adana virus is the third virus of the Salehabad virus species for which the complete sequence has been determined. To understand the epidemiology of Adana virus, a seroprevalence study using microneutralization assay was performed to detect the presence of specific antibodies in human and domestic animal sera collected in Adana as well as Mersin province, located 147 km west of Adana. The results demonstrate that the virus is present in both provinces. High seroprevalence rates in goats, sheep, and dogs support intensive exposure to Adana virus in the region, which has not been previously reported for any virus included in the Salehabad serocomplex; however, low seroprevalence rates in humans suggest that Adana virus is not likely to constitute an important public health problem in exposed human populations, but this deserves further studies.

Importance: Until recently, in the genus Phlebovirus, the Salehabad virus species consisted of two viruses: Salehabad virus, isolated from sand flies in Iran, and Arbia virus, isolated from sand flies in Italy. Here we present the isolation and complete genome characterization of the Adana virus, which we propose to be included in the Salehabad virus species. To our knowledge, this is the first report of the isolation and complete genome characterization, from sand flies in Turkey, of a Salehabad virus-related phlebovirus with supporting seropositivity in the Mediterranean, Aegean, and Central Anatolia regions, where phleboviruses have been circulating and causing outbreaks. Salehabad species viruses have generally been considered to be a group of viruses with little medical or veterinary interest. This view deserves to be revisited according to our results, which indicate a high animal infection rate of Adana virus and recent evidence of human infection with Adria virus in Greece.

FIG 1

Geographic representation of the results.

FIG 2

Negative staining electron microscopy of Vero cell culture supernatant medium at day five after infection with the Adana virus.

FIG 3

Phylogenetic analysis of the phlebovirus amino acid sequences. (A) L protein; (B) Gn protein; (C) Gc protein; (D) nucleocapsid protein; (E) nonstructural protein. The species recognized by ICTV are indicated in boldface and italics, and the tentative species are indicated in boldface roman. The GenBank accession numbers of all the phleboviruses included in the analysis can be found in Table S1 in the supplemental material.

FIG 3

Phylogenetic analysis of the phlebovirus amino acid sequences. (A) L protein; (B) Gn protein; (C) Gc protein; (D) nucleocapsid protein; (E) nonstructural protein. The species recognized by ICTV are indicated in boldface and italics, and the tentative species are indicated in boldface roman. The GenBank accession numbers of all the phleboviruses included in the analysis can be found in Table S1 in the supplemental material.

FIG 3

Phylogenetic analysis of the phlebovirus amino acid sequences. (A) L protein; (B) Gn protein; (C) Gc protein; (D) nucleocapsid protein; (E) nonstructural protein. The species recognized by ICTV are indicated in boldface and italics, and the tentative species are indicated in boldface roman. The GenBank accession numbers of all the phleboviruses included in the analysis can be found in Table S1 in the supplemental material.