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5 waves

Printed From: Pandemic Talk - Coronavirus Discussion Forum
Category: New emerging Diseases / Flu Tracking
Forum Name: Avian Flu
Forum Description: (Tracking avian flu outbreaks in the U.S and worldwide)
URL: http://www.avianflutalk.com/forum_posts.asp?TID=37337
Printed Date: August 12 2020 at 11:58am


Topic: 5 waves
Posted By: Kilt5
Subject: 5 waves
Date Posted: May 15 2018 at 4:14am

ABSTRACT

H7N9 virus has caused five infection waves since it emerged in 2013. The highest number of human cases was seen in wave 5; however, the underlying reasons have not been thoroughly elucidated. In this study, the geographical distribution, phylogeny, and genetic evolution of 240 H7N9 viruses in wave 5, including 35 new isolates from patients and poultry in nine provinces, were comprehensively analyzed together with strains from first four waves. Geographical distribution analysis indicated that the newly emerging highly pathogenic (HP) and low-pathogenicity (LP) H7N9 viruses were cocirculating, causing human and poultry infections across China. Genetic analysis indicated that dynamic reassortment of the internal genes among LP-H7N9/H9N2/H6Ny and HP-H7N9, as well as of the surface genes, between the Yangtze and Pearl River Delta lineages resulted in at least 36 genotypes, with three major genotypes (G1 [A/chicken/Jiangsu/SC537/2013-like], G3 [A/Chicken/Zhongshan/ZS/2017-like], and G11 [A/Anhui/40094/2015-like]). The HP-H7N9 genotype likely evolved from G1 LP-H7N9 by the insertion of a KRTA motif at the cleavage site (CS) and then evolved into 15 genotypes with four different CS motifs, including PKGKRTAR/G, PKGKRIAR/G, PKRKRAAR/G, and PKRKRTAR/G. Approximately 46% (28/61) of HP strains belonged to G3. Importantly, neuraminidase (NA) inhibitor (NAI) resistance (R292K in NA) and mammalian adaptation (e.g., E627K and A588V in PB2) mutations were found in a few non-human-derived HP-H7N9 strains. In summary, the enhanced prevalence and diverse genetic characteristics that occurred with mammalian-adapted and NAI-resistant mutations may have contributed to increased numbers of human infections in wave 5.


http://jvi.asm.org/content/92/11/e00301-18.short" rel="nofollow - New Threats from Journal of Virology-19 hours ago
H7N9 virus has caused five infection waves since it emerged in 2013. The highest number of human cases was seen in wave 5; however, the ...




Replies:
Posted By: EdwinSm,
Date Posted: May 15 2018 at 10:18pm
I wonder what wave six will do. 



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