The molecular basis of the pathogenicity of the Dutch highly pathogenic human influenza A H7N7 viruses

J Infect Dis. 2007 Jul 15;196(2):258-65. doi: 10.1086/518792. Epub 2007 Jun 4.


During the highly pathogenic avian influenza (HPAI) H7N7 virus outbreak in The Netherlands in 2003, 88 infected persons suffered from mild illnesses, and 1 died of pneumonia. Here, we studied which of the 14 amino acid substitutions observed between the fatal case (FC) virus and a conjunctivitis case (CC) virus determined the differences in virus pathogenicity. In virus-attachment experiments, the CC and FC viruses revealed marked differences in binding to the lower respiratory tract of humans. In a mouse model, the hemagglutinin (HA) gene of the FC virus was a determinant of virus tissue distribution. The lysine at position 627 of basic polymerase 2 (PB2) of the FC virus was the major determinant of pathogenicity and tissue distribution. Thus, remarkable similarities were revealed between recent HPAI H5N1 and H7N7 viruses. We conclude that the influenza virus HA and PB2 genes should be the prime targets for molecular surveillance during outbreaks of zoonotic HPAI viruses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Conjunctivitis, Viral / pathology
  • Disease Models, Animal
  • Female
  • Hemagglutinin Glycoproteins, Influenza Virus / chemistry
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics*
  • Humans
  • Influenza A Virus, H5N1 Subtype / genetics
  • Influenza A Virus, H7N7 Subtype / genetics*
  • Influenza A Virus, H7N7 Subtype / pathogenicity*
  • Influenza in Birds / genetics
  • Influenza, Human / genetics
  • Influenza, Human / pathology*
  • Lung / pathology
  • Lung / virology
  • Mice
  • Molecular Sequence Data
  • Netherlands
  • Poultry
  • Reassortant Viruses / genetics
  • Reassortant Viruses / pathogenicity*
  • Virus Attachment


  • Hemagglutinin Glycoproteins, Influenza Virus