Epidemiology, Genetic Characterization, and Pathogenesis of Avian Influenza H5N8 Viruses Circulating in Northern and Southern Parts of Egypt, 2017–2019

Tarek, Mohamed; Naguib, Mahmoud M.; Arafa, Abdel Satar; Tantawy, Laila; Selim, Karim; Talaat, Shaimaa; Sultan, Hesham

doi:10.3390/ani11082208

Cited by 14 publications

(18 citation statements)

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“…However, the high prevalence of AIV H5N8 in vaccinated poultry, the increased distinction of circulating 2020/2021 viruses from vaccine strains and the selection of mutations in the HA immunogenic epitopes (i.e., R72N/S, T140A) highlight the need to revise the efficiency of the currently licensed H5 vaccines in Egypt. Furthermore, our sequence analyses confirmed previous findings of multiple introductions of H5N8 from Eurasia into Egypt via wild birds in 2016–2019 [ 23 , 24 , 25 , 36 , 43 ] and revealed the establishment of a new sub-cluster in 2020/2021. These results indicate the importance of poultry in Egypt in the global epidemiology of H5N8 clade 2.3.4.4b along the migration flyways and as an endemic hotspot for H5N8 in the Middle East.…”

Section: Discussionsupporting

confidence: 89%

“…Samples were purified from 1.5% gel using QIAquick Gel Extraction Kit (Qiagen, Hilden, Germany). Purified segments were subjected to sequencing using BigDye Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems, Waltham, MA, USA) and universal forward and reverse primers as previously published [ 35 , 36 ]. Sequences were assembled and edited using Geneious Prime® 2021.0.1.…”

Section: Methodsmentioning

confidence: 99%

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Isolation of Genetically Diverse H5N8 Avian Influenza Viruses in Poultry in Egypt, 2019–2021

Salaheldin

Elbestawy

Abdelkader

et al. 2022

Viruses

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The global spread of avian influenza virus (AIV) of clade 2.3.4.4b since 2016 has caused severe losses in wild birds and poultry and has posed a risk for the infection of mammals including humans. The vaccination of poultry has been used to limit the spread of the virus and mitigate its socioeconomic impact. Here, we describe H5N8 epidemics in chickens, turkeys and ducks from different localities in Egypt from 2019 to 2021. About 41.7% (n = 88/211) flocks were tested positive by RT-qPCR for H5N8 viruses with prevalence rates of 45.1% (n = 65/144) and 34.3% (n = 23/67) in vaccinated and non-vaccinated flocks, respectively. A sequence analysis of the hemagglutinin and neuraminidase genes indicated not only the multiple introduction events of H5N8 viruses in Egypt but also the establishment of endemic viruses in commercial poultry in 2020/2021. The recent H5N8 viruses in poultry in Egypt are genetically distinct from the majority of licensed vaccines used in the field. Together, our findings indicate that poultry in Egypt is an endemic center for clade 2.3.4.4b in the Middle East. The efficiency of current vaccines should be regularly evaluated and updated to fully protect poultry flocks in Egypt against H5N8 viruses.

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Section: Discussionsupporting

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Isolation of Genetically Diverse H5N8 Avian Influenza Viruses in Poultry in Egypt, 2019–2021

Salaheldin

Elbestawy

Abdelkader

et al. 2022

Viruses

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“…In Egypt, many factors may impact the prevalence and distribution of HPAI viruses, such as the density of birds and the weather. The cold weather might have favored the spread of both subtypes in the winter season, where a higher prevalence in the north of Egypt was found, compared to the warmer area in the south part of Egypt [ 40 ]. The national surveillance program that has been carried out in Egypt, depending on both active surveillance (collecting samples from farms, backyards, and live bird markets) and passive surveillance (reported cases by bird owners), has provided a robust data stream to uncover the full landscape of AIV dynamics.…”

Section: Discussionmentioning

confidence: 99%

Temporal Dynamics of Influenza A(H5N1) Subtype before and after the Emergence of H5N8

Amer

Rabie

et al. 2021

Viruses

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Highly pathogenic avian influenza (HPAI) viruses continue to circulate worldwide, causing numerous outbreaks among bird species and severe public health concerns. H5N1 and H5N8 are the two most fundamental HPAI subtypes detected in birds in the last two decades. The two viruses may compete with each other while sharing the same host population and, thus, suppress the spread of one of the viruses. In this study, we performed a statistical analysis to investigate the temporal correlation of the HPAI H5N1 and HPAI H5N8 subtypes using globally reported data in 2015–2020. This was joined with an in-depth analysis using data generated via our national surveillance program in Egypt. A total of 6412 outbreaks were reported worldwide during this period, with 39% (2529) as H5N1 and 61% (3883) as H5N8. In Egypt, 65% of positive cases were found in backyards, while only 12% were found in farms and 23% in live bird markets. Overall, our findings depict a trade-off between the number of positive H5N1 and H5N8 samples around early 2017, which is suggestive of the potential replacement between the two subtypes. Further research is still required to elucidate the underpinning mechanisms of this competitive dynamic. This, in turn, will implicate the design of effective strategies for disease control.

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“…2 ). The H5 clade 2.3.4.4b had evolved at around 2016 and currently this clade predominates worldwide ( World Health Organization, 2018 ; Lee et al, 2017b ; Lee et al, 2017a ; Chen et al, 2019 ; Le & Nguyen, 2014 ; Yamaji et al, 2020 ; Gu et al, 2013 ; Tarek et al, 2021 ; Zhang et al, 2020 ; Pohlmann et al, 2019 ; Laleye et al, 2021 ; Lewis et al, 2021 ; Globig et al, 2017 ; Liang et al, 2020 ; Baek et al, 2021 ).…”

Section: Resultsmentioning

confidence: 99%

Highly pathogenic avian influenza virus of the A/H5N8 subtype, clade 2.3.4.4b, caused outbreaks in Kazakhstan in 2020

Amirgazin

Shevtsov

Karibayev³

et al. 2022

PeerJ

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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.

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Epidemiology, Genetic Characterization, and Pathogenesis of Avian Influenza H5N8 Viruses Circulating in Northern and Southern Parts of Egypt, 2017–2019

Cited by 14 publications

References 40 publications

Isolation of Genetically Diverse H5N8 Avian Influenza Viruses in Poultry in Egypt, 2019–2021

Isolation of Genetically Diverse H5N8 Avian Influenza Viruses in Poultry in Egypt, 2019–2021

Temporal Dynamics of Influenza A(H5N1) Subtype before and after the Emergence of H5N8

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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