A two-year monitoring period of the genetic properties of clade 2.3.2.1c H5N1 viruses in Nigeria reveals the emergence and co-circulation of distinct genotypes

Abstract

Phylogenetic analyses of the complete genomes of the highly pathogenic avian influenza (HPAI) 2.3.2.1c H5N1 virus strains causing outbreaks in Nigeria's poultry population from 2014 to 2016 showed evidence of distinct co-circulating genotypes and the emergence of reassortant viruses. One of these reassortants became the predominant strain by 2016, and the NA protein of this strain possessed the V96A substitution known to confer reduced susceptibility to neuraminidase inhibiting antiviral drugs. Our findings also demonstrated evolutionary relationships between Nigerian isolates and European and Middle Eastern strains of H5N1 which provides further evidence for the proposed role of migratory birds in spreading the virus, although the involvement of the live poultry trade cannot be excluded. Efforts must be directed towards improving biosecurity and gaining the cooperation of poultry farmers for more effective control of HPAI, in order to mitigate the emergence of HPAI strains in Nigeria with biological properties that are potentially even more dangerous to animals and humans.

A Highly Pathogenic H5N1 Influenza A Virus Isolated from a Flamingo on the Caspian Sea Shore

“…The deduced amino acid sequence of the hemagglutinin (HA) gene cleavage site revealed the presence of the PQRERRRKR*GLF motif that is typical of HPAI. BLASTn analyses showed significant genetic similarity of the flamingo isolate in all eight genes to the highly pathogenic H5N1 influenza viruses that were isolated from poultry in West Africa (Table 1) and caused outbreaks there (7). Phylogenetic analysis showed that the HA gene of the isolate was closely related to that of isolates from clade 2.3.2.1c, which has been identified since 2014 in Asia, the Middle East, Eastern Europe, and West Africa (Fig.…”

Avian influenza overview September – November 2017

“…There is also evidence of the intersubtype reassortments (including A(H5N1)/A(H9N2)) of clades 2.3.2.1a (Marinova-Petkova et al, 2016b) or 7.2 . The analysis of the whole-genome sequences from the (A)H5N1 virus clade 2.3.2.1c detected in poultry in Nigeria in 2014-2016 showed the dynamic nature of the epidemic in this country, demonstrated by the emergence and co-circulation of different genotypes (Laleye et al, 2017).…”

“…The analysis of the whole-genome sequences from the (A)H5N1 virus clade 2.3.2.1c detected in poultry in Nigeria in 2014-2016 showed the dynamic nature of the epidemic in this country, demonstrated by the emergence and co-circulation of different genotypes(Laleye et al, 2017). The analysis of the whole-genome sequences from the (A)H5N1 virus clade 2.3.2.1c detected in poultry in Nigeria in 2014-2016 showed the dynamic nature of the epidemic in this country, demonstrated by the emergence and co-circulation of different genotypes(Laleye et al, 2017).…”

Novel Mutations Evading Avian Immunity around the Receptor Binding Site of the Clade 2.3.2.1c Hemagglutinin Gene Reduce Viral Thermostability and Mammalian Pathogenicity

“…Some clade 2.3.2 viruses evolved into clade 2.3.2.1 and further diversified into 2.3.2.1a, b, and c in 2009 [6,7]. Clade 2.3.2.1c viruses have spread from Far East and South East Asian countries to Dubai, Bulgaria, Romania, and Nigeria and have become enzootic in Asian countries [8,9,10,11].…”