Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany

Abstract

Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.

Keywords: Germany; H5N8 subtype; highly pathogenic; influenza; influenza A virus; poultry; viruses; wild birds; zoonoses.

Figure 1

Pathomorphologic results for 2 dead turkeys infected with influenza A(H5N8) virus, Germany. A, C) Gross pathology showing acute, focally extensive to diffuse pancreatic necrosis with fibrinous serositis. B, D) Hematoxylin and eosin staining showing acute coagulative necrosis of the pancreas and multifocal staining within the exocrine pancreatic acini for influenza A virus nucleocapsid protein. Scale bars indicate 50 µm (B) and 100 µm (D).

Figure 2

Phylogenetic analysis of hemagglutinin (HA) 1 nucleotide sequences of highly pathogenic avian influenza viruses subtype H5 from Southeast Asia and Germany. Insert shows the structural model of the HA protein of the German H5N8 isolate AR2472/14. A) Nucleotide sequences encoding the membrane-distal part of the HA1 of influenza A(H5N8) viruses were retrieved from public databases, aligned by using MAFFT (http://mafft.cbrc.jp/alignment/software) and phylogenetically analyzed by using a maximum-likelihood approach (best fit model: K3Pu+G4) implemented in IQ-Tree (http://www.cibiv.at/software/iqtree) (12). Numbers at nodes represent surrogates of branching robustness obtained by an ultrafast bootstrap approach (12). Scale bar indicates nucleotide substitutions per site. B) Model of an HA monomer of AR2472/14 with PDB:3FKU used as template. Green depicts unique mutations distinguishing this virus from other South Korea–origin avian influenza (H5N8) viruses; red indicates additional substitutions relative to the closest vaccine candidate within clade 2.3.4.4. (A/Sichuan/26221/2014 [H5N6]).