Usutu Virus RNA in Mosquitoes, Israel, 2014-2015

Abstract

We identified Usutu virus (USUV) RNA in 6 pools of mosquitoes trapped in northern Israel during 2014-2015. These Israeli strains were most similar to strains identified in Senegal and Germany, which further elucidates common ancestry and evolutionary dynamics of USUV. Our findings suggest that human infection with USUV might occur in Israel.

Keywords: Israel; USUV; Usutu virus; WNV; West Nile virus; flavivirus; mosquitoes; virus RNA; viruses.

Figure 1

Spatial distribution of collection sites and Usutu virus infectious mosquitoes, Israel 2014–2015. Small gray circles indicate collection sites. Red symbols and numbers indicate sites of Usutu virus–infected mosquitoes.

Figure 2

Phylogenetic tree of Usutu virus strains, Israel, 2014–2015. A) Structural protein genes. B) Nonstructural protein 5 genes. Analysis was conducted by using the maximum-likelihood method implemented in MEGA 6.0 software (http://www.megasoftware.net/). Robustness of branching pattern was tested by using 1,000 bootstrap replications. Percentage of successful bootstrap replicates is indicated at nodes (only values >70% are shown). Diamonds indicate virus strains sequenced in this study. Reference strains are indicated by GenBank accession numbers and country and year of isolation. Scale bars indicate nucleotide substitutions per site.