Avian Influenza A virus current situation summary

Avian Influenza A virus current situation summary

HPAI clade 2.3.4.4b viruses circulate from 2018 till now, In 2020, HPAI clade 2.3.4.4b outbreaks occur globally, Human cases of highly pathogenic avian influenza (HPAI) A(H5N1) have been identified worldwide since 2022.
Approximately, all human cases reported globally were associated with poultry exposure.
Global reported H5N1 human cases from 2022 to 2024 in Cambodia, Chile, China, Ecuador, Spain, United kingdom, United states & Vietnam from clade 2.3.4.4 (CDC, 2024).
The beginning of 2024, HPAI H5N1 cases reported in animals such as Cattle & Cat, Genetically characterize the HPAI from dairy cattle share nearly identical genome sequences, forming a new genotype B3.13 within the 2.3.4.4b clade. B3.13 viruses underwent two 21 reassortment events since 2023 and exhibit critical mutations in HA, M1, and NS (nonstructural) genes but lack 22 critical mutations in PB2 and PB1 genes, which enhance virulence or adaptation to mammals (Xiao Hu, et al., 2024).
When review the human outbreaks which occurred in Egypt (Figure), we will found out a moderate outbreak of (H5N1 clade 2.2.1) started from 2006 to 2011, then became low till starting of 2014, at the end of 2014 to 2015 huge outbreak of (H5N1 clade 2.2.1.2) occurred, these outbreaks affected negatively on the Health (Animal & Human) and Economic (poultry industry).
All of these events must be considered when dealing with the current situation of H5N1 clade 2.3.4.4b to prevent/limit the drawbacks on Health & Economics and try to reduce the opportunity for further mutations.

So, FAO & WHO Recommend: –
the candidate H5N1 clade 2.3.4.4b inactivated vaccine (high Protection and low shedding & mutation).
NB:- Not only HA gene is important, but NS & M genes also have a role.

Article Reference :

https://www.cdc.gov/bird-flu/php/technical-report/h5n1-06052024.html (CDC, 2024) Xiao Hu, Anugrah Saxena, Drew R. Magstadt, Phillip C. Gauger, Eric R. Burrough, Jianqiang Zhang, Chris Siepker, Marta Mainenti, Patrick J. Gorden, Paul J. Plummer & Ganwu Li (2024) Genomic characterization of highly pathogenic avian influenza A H5N1 virus newly emerged in dairy cattle, Emerging Microbes & Infections, 13:1, 2380421, DOI: 10.1080/22221751.2024.2380421
Tags :
Avian Influenza,H5Nx,HPAI,Human,Poultry,Zoonotic
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