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. 2019 Oct;25(10):1988-1991.
doi: 10.3201/eid2510.190506. Epub 2019 Oct 17.

Emergence of Influenza A(H7N4) Virus, Cambodia

Dhanasekaran Vijaykrishna, Yi-Mo Deng, Miguel L Grau, Matthew Kay, Annika Suttie, Paul F Horwood, Wantanee Kalpravidh, Filip Claes, Kristina Osbjer, Phillipe Dussart, Ian G Barr, Erik A Karlsson

Emergence of Influenza A(H7N4) Virus, Cambodia

Dhanasekaran Vijaykrishna et al. Emerg Infect Dis. 2019 Oct.

Abstract

Active surveillance in high-risk sites in Cambodia has identified multiple low-pathogenicity influenza A(H7) viruses, mainly in ducks. None fall within the A/Anhui/1/2013(H7N9) lineage; however, some A(H7) viruses from 2018 show temporal and phylogenetic similarity to the H7N4 virus that caused a nonfatal infection in Jiangsu Province, China, in December 2017.

Keywords: Cambodia; H7N4; influenza surveillance; influenza virus; live poultry markets; phylogenetics; subtype A/H7N4; viruses; whole genome sequencing; zoonotic infection.

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Figures

Figure
Figure
Maximum-likelihood phylogeny of the evolutionary origins of influenza A(H7N4) virus in Cambodia and comparison with reference isolates. H7 hemagglutinin (A) and N4 neuraminidase (B) genes were inferred using a general time-reversible nucleotide substitution model with a gamma distribution of among-site rate variation in RAxML version 8 (https://cme.h-its.org/exelixis/web/software/raxml) and visualized using Figtree version 1.4 (http://tree.bio.ed.ac.uk/software/figtree/). Branch support values were generated using 1,000 bootstrap replicates. Green indicates A/Anhui 1/2013-like lineage viruses; red indicates viruses from Cambodia; blue indicates A/Jiangsu/2018-like viruses. Scale bars represent nucleotide substitutions per site.
See this image and copyright information in PMC

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