Novel reassortant of swine influenza H1N2 virus in Germany

1 Institut für Virologie und Antivirale Therapie, Universitätsklinikum, Friedrich Schiller Universität, Hans-Knöll-Str. 2, D-07745 Jena, Germany 2 Impfstoffwerk Dessau-Tornau (IDT), Bereich Forschung und Entwicklung, Streetzer Weg 15a, D-06861 Dessau-Roßlau, Germany Correspondence Roland Zell Roland.Zell{at}med.uni-jena.de European porcine H1N2 influenza viruses arose after multiple reassortment steps involving a porcine influenza virus with avian-influenza-like internal segments and human H1N1 and H3N2 viruses in 1994. In Germany, H1N2 swine influenza viruses first appeared in 2000. Two German H1N2 swine influenza virus strains isolated from pigs with clinical symptoms of influenza are described. They were characterized by the neutralization test, haemagglutination inhibition (HI) test and complete sequencing of the viral genomes. The data demonstrate that these viruses represent a novel H1N2 reassortant. The viruses showed limited neutralization by sera raised against heterologous A/sw/Bakum/1832/00-like H1N2 viruses. Sera pools from recovered pigs showed a considerably lower HI reaction, indicative of diagnostic difficulties in using the HI test to detect these viruses with A/sw/Bakum/1832/00-like H1N2 antigens. Genome sequencing revealed the novel combination of the human-like HAH1 gene of European porcine H1N2 influenza viruses and the NAN2 gene of European porcine H3N2 viruses. The GenBank/EMBL/DDBJ accession numbers for the nucleotide sequences reported in this study are EU053130–EU053151 and EU163946–EU163949.