title: Highly pathogenic avian influenza (H5N1) in Nigeria in 2015: evidence of widespread circulation of WA2 clade 2.3.2.1c.
abstract: Genetic analysis of the complete haemagglutinin (HA) gene of fourteen Nigerian avian influenza isolates showed multiple basic amino acids at the cleavage site (321PQRERRRKdelR*GLF333), characteristic of highly pathogenic avian influenza (HPAI). Substitution of Gln to Lys at position 322 (H5-specific numbering) was identified in one isolate. In some isolates, amino acid substitutions were observed across the HA gene, however the receptor binding, antigenic and glycosylation sites were conserved in all. Phylogenetic analysis revealed two clusters of the HPAI H5N1 clade 2.3.2.1c. Cluster I has close genetic relatedness (97.8-99.8%) with viruses circulating in some West Africa countries. Cluster II shared close identity (98.9-100.0%) with isolates from Europe, Côte d'Ivoire and Niger and viruses from this cluster were detected in five of the eleven states investigated in Nigeria. In view of the continuous HPAI outbreaks being recorded in Nigerian poultry and the zoonotic potential of the virus, extensive and continued characterization of HPAI isolates is advocated.
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria. ismaila.shittu@gmail.com.
authors.forename: Ismaila
authors.identifier: http://orcid.org/0000-0002-2977-9578
authors.initials: I
authors.lastname: Shittu
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Clement A
authors.initials: CA
authors.lastname: Meseko
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Dorcas A
authors.initials: DA
authors.lastname: Gado
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Abraham K
authors.initials: AK
authors.lastname: Olawuyi
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Chinonyerem N
authors.initials: CN
authors.lastname: Chinyere
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Anefu
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: Ponman
authors.initials: P
authors.lastname: Solomon
authors.affiliation: Central Diagnostic Division, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Okewole
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria.
authors.forename: David
authors.initials: D
authors.lastname: Shamaki
authors.affiliation: Virology Division, National Veterinary Research Institute, PMB 01, Vom, 930010, Plateau State, Nigeria. tmjoannis@gmail.com.
authors.forename: Tony M
authors.initials: TM
authors.lastname: Joannis
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002645:Chickens; D004196:Disease Outbreaks; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D009549:Nigeria / Q000453:epidemiology; D010802:Phylogeny; D011201:Poultry Diseases / Q000453:epidemiology / Q000821:virology*; D014774:Virulence
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus
keywords: Clade 2.3.2.1c; Evolution; H5N1; Haemagglutinin gene; Highly pathogenic avian influenza; Nigeria