HIGHLY PATHOGENIC AVIAN INFLUENZA VIRUS OF THE A/H5N8 SUBTYPE, CLADE 2.3.4.4B, CAUSED OUTBREAKS IN KAZAKHSTAN IN 2020
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Date
2022
Authors
Amirgazin, Asylulan
Shevtsov, Alexandr
Karibayev, Talgat
Berdikulov, Maxat
Kozhakhmetova, Tamila
Syzdykova, Laura
Ramankulov, Yerlan
Shustov, Alexandr V.
Journal Title
Journal ISSN
Volume Title
Publisher
PeerJ
Abstract
Background. Large poultry die-offs happened in Kazakhstan during autumn of 2020.
The birds’ disease appeared to be avian influenza. Northern Kazakhstan was hit first
and then the disease propagated across the country affecting eleven provinces. This
study reports the results of full-genome sequencing of viruses collected during the
outbreaks and investigation of their relationship to avian influenza virus isolates in
the contemporary circulation in Eurasia.
Methods. Samples were collected from diseased birds during the 2020 outbreaks in
Kazakhstan. Initial virus detection and subtyping was done using RT-PCR. Ten samples
collected during expeditions to Northern and Southern Kazakhstan were used for
full-genome sequencing of avian influenza viruses. Phylogenetic analysis was used to
compare viruses from Kazakhstan to viral isolates from other world regions.
Results. Phylogenetic trees for hemagglutinin and neuraminidase show that viruses
from Kazakhstan belong to the A/H5N8 subtype and to the hemagglutinin H5 clade
2.3.4.4b. Deduced hemagglutinin amino acid sequences in all Kazakhstan’s viruses
in this study contain the polybasic cleavage site (KRRKR-G) indicative of the highly
pathogenic phenotype. Building phylogenetic trees with the Bayesian phylogenetics
results in higher statistical support for clusters than using distance methods. The
Kazakhstan’s viruses cluster with isolates from Southern Russia, the Russian Caucasus,
the Ural region, and southwestern Siberia. Other closely related prototypes are from
Eastern Europe. The Central Asia Migratory Flyway passes over Kazakhstan and birds
have intermediate stops in Northern Kazakhstan. It is postulated that the A/H5N8
subtype was introduced with migrating birds.
Conclusion. The findings confirm the introduction of the highly pathogenic avian
influenza viruses of the A/Goose/Guangdong/96 (Gs/GD) H5 lineage in Kazakhstan.
This virus poses a tangible threat to public health. Considering the results of this
study, it looks justifiable to undertake measures in preparation, such as install sentinel
surveillance for human cases of avian influenza in the largest pulmonary units, develop
a human A/H5N8 vaccine and human diagnostics capable of HPAI discrimination.
Description
Keywords
Type of access: Open Access, Highly pathogenic avian influenza virus, Kazakhstan, Whole genome sequencing, A/H5N8, Gs/GD lineage, Birds migration, Central Asia Migratory Flyway, Phylogenetic analysis, Bayesian MCMC
Citation
Amirgazin, A., Shevtsov, A., Karibayev, T., Berdikulov, M., Kozhakhmetova, T., Syzdykova, L., Ramankulov, Y., & Shustov, A. V. (2022). Highly pathogenic avian influenza virus of the A/H5N8 subtype, clade 2.3.4.4b, caused outbreaks in Kazakhstan in 2020. PeerJ, 10, e13038. https://doi.org/10.7717/peerj.13038