West Nile Virus in Common Wild Avian Species in Israel

Abstract

In order to evaluate the contribution of different wild bird species to West Nile virus (WNV) circulation in Israel, during the months preceding the 2018 outbreak that occurred in Israel, we randomly sampled 136 frozen carcasses of a variety of avian species. Visceral and central nervous system (CNS) tissue pools were tested using WNV NS2A RT qPCR assay; of those, 15 (11.03%, 95% CI: 6.31–17.54%) tissue pools were positive. A total of 13 out of 15 WNV RT qPCR positive samples were successfully sequenced. Phylogenetic analysis indicated that all WNV isolates were identified as lineage 1 and all categorized as cluster 2 eastern European. Our results indicated that WNV isolates that circulated within the surveyed wild birds in spring 2018 were closely related to several of the isolates of the previously reported 2018 outbreak in birds in Israel and that the majority of infected birds were of local species.

Spatial and temporal dynamics of West Nile virus between Africa and Europe

“…Looking at the two major Eastern and Western phylogeography and genomic epidemiology of WNV L1 and L2 strains between Africa and Europe, they interestingly overlap with two most important Afro-Palaearctic bird migration flyways 34 , suggesting a possible role of migratory bird species as carriers of WNV across different geographical areas. This scenario is supported by several studies showing WNV to be carried around by migratory birds 2 , 6 , 10 , 35 , which move across the globe ( https://migrationatlas.org/ ) spreading the virus from their original niches to new areas during this natural process 8 . In fact, during their annual cycle, birds cross the borders of numerous countries with multiple stopovers while heading to their breeding and non-breeding grounds 36 .…”

“…In fact, during their annual cycle, birds cross the borders of numerous countries with multiple stopovers while heading to their breeding and non-breeding grounds 36 . At stopover sites, the virus can spread and become established depending on the composition of the mosquito and resident bird communities 6 , 37 . Each bird species appears to be characterised by a variability in migration patterns, creating a complex network of connectivity between Africa and Europe ( https://migrationatlas.org/ ), which may underlie the enormous and variable spread of WNV L1 and L2 strains worldwide.…”

“…Considered one of the main One Health challenges, this arthropod-borne virus belonging to the genus Flavivirus , family Flaviviridae , and Japanese Encephalitis serocomplex, is maintained in nature through a transmission cycle involving wild birds and vector-competent mosquitoes 3 . Although in the majority of the susceptible bird species infection generally does not lead to severe clinical signs, in some species it might cause severe neurological complications, including death 4 – 6 . Competent vector mosquitoes, mainly belonging to the Culex ( Cx .)…”

West Nile Virus Lineage 2 in Free-Living Corvus cornix Birds in Poland

“…The Poland bird checklist indexes 467 bird species belonging to 27 families wintering in Poland on 31 December 2022 (according to the division adopted by the Faunistics Commission of the Ornithological Section of the Polish Zoological Society). Birds belonging to Corvidae are described as a reservoir for WNV in Europe [ 29 , 30 ]. This highlights the need to extend the avifauna surveillance program in Poland in order to detect early WNV circulation in the country.…”

“…Most important from an epidemiological point of view were the birds belonging to Passeriformes . They are the primary birds involved as a reservoir of the virus and are also sensitive to WNV infection [ 30 ].…”