Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey

Background: Active vector surveillance provides an efficient tool for monitoring the presence or spread of emerging or re-emerging vector-borne viruses. This study was undertaken to investigate the circulation of flaviviruses. Mosquitoes were collected from 58 locations in 10 provinces across the Aegean, Thrace and Mediterranean Anatolian regions of Turkey in 2014 and 2015. Following morphological identification, mosquitoes were pooled and screened by nested and real-time PCR assays. Detected viruses were further characterised by sequencing. Positive pools were inoculated onto cell lines for virus isolation. Next generation sequencing was employed for genomic characterisation of the isolates. Results: A total of 12,711 mosquito specimens representing 15 species were screened in 594 pools. Eleven pools (2%) were reactive in the virus screening assays. Sequencing revealed West Nile virus (WNV) in one Culex pipiens (s.l.) pool from Thrace. WNV sequence corresponded to lineage one clade 1a but clustered distinctly from the Turkish prototype isolate. In 10 pools, insect-specific flaviviruses were characterised as Culex theileri flavivirus in 5 pools of Culex theileri and one pool of Cx. pipiens (s.l.), Ochlerotatus caspius flavivirus in two pools of Aedes (Ochlerotatus) caspius, Flavivirus AV-2011 in one pool of Culiseta annulata, and an undetermined flavivirus in one pool of Uranotaenia unguiculata from the Aegean and Thrace regions. DNA forms or integration of the detected insect-specific flaviviruses were not observed. A virus strain, tentatively named as “Ochlerotatus caspius flavivirus Turkey”, was isolated from an Ae. caspius pool in C6/36 cells. The viral genome comprised 10,370 nucleotides with a putative polyprotein of 3,385 amino acids that follows the canonical flavivirus polyprotein organisation. Sequence comparisons and phylogenetic analyses revealed the close relationship of this strain with Ochlerotatus caspius flavivirus from Portugal and Hanko virus from Finland. Several conserved structural and amino acid motifs were identified. Conclusions: We identified WNV and several distinct insect-specific flaviviruses during an extensive biosurveillance study of mosquitoes in various regions of Turkey in 2014 and 2015. Ongoing circulation of WNV is revealed, with an unprecedented genetic diversity. A probable replicating form of an insect flavivirus identified only in DNA form was detected

Taxonomy of the order Bunyavirales : second update 2018

In October 2018, the order Bunyavirales was amended by inclusion of the family Arenaviridae, abolishment of three families, creation of three new families, 19 new genera, and 14 new species, and renaming of three genera and 22 species. This article presents the updated taxonomy of the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).Non peer reviewe

2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

Emergence And Co-Infections Of West Nile Virus And Toscana Virus In Eastern Thrace, Turkey

The objective of this study was to identify the impact of West Nile virus (WNV) and Toscana virus (TOSV) in febrile diseases of unknown aetiology in Eastern Thrace, Turkey; this study was conducted during August-October 2012, and included 18 clinical cases and 296 blood donors for local serosurveillance. Antibodies were determined via commercial assays and further tested for specificity via neutralization assays (NA). Viral RNAs were sought via specific and/or generic primers. WNV infections were diagnosed in seven patients (38.8%), detected via RNA+IgM in four, RNA in one and IgM and low avidity IgG in two cases. The most common symptom was fever (>38 degrees C), followed by headache, malaise/fatigue, myalgia/arthralgia, muscle stiffness/lower back pain, anorexia, nausea/vomiting, diarrhoea, supraorbital/retrobulbar pain and abdominal pain. Neurological symptoms were noted in one individual. WNV strains in RNA-detectable patients were characterized as lineage 1. TOSV RNA or IgM were identified in two individuals with confirmed WNV infections and in one patient without evidence of WNV exposure. The clinical and laboratory findings in individuals with WNV/TOSV co-infection were comparable to those in WNV-induced disease. The TOSV strain in the patient with detectable viral RNA was characterized as genotype A. In local blood donors, seroreactivity for specific WNV and TOSV immunoglobulins was observed in 1.7% (5/296) and 14.4% (26/180), respectively. These findings indicate the emergence of WNV and TOSV-associated diseases in Eastern Thrace. WNV/TOSV co-infections were documented for the first time.WoSScopu