The potential of avian H1N1 influenza A viruses to replicate and cause disease in mammalian models

PLoS One. 2012;7(7):e41609. doi: 10.1371/journal.pone.0041609. Epub 2012 Jul 25.


H1N1 viruses in which all gene segments are of avian origin are the most frequent cause of influenza pandemics in humans; therefore, we examined the disease-causing potential of 31 avian H1N1 isolates of American lineage in DBA/2J mice. Thirty of 31 isolates were very virulent, causing respiratory tract infection; 22 of 31 resulted in fecal shedding; and 10 of 31 were as pathogenic as the pandemic 2009 H1N1 viruses. Preliminary studies in BALB/cJ mice and ferrets showed that 1 of 4 isolates tested was more pathogenic than the pandemic 2009 H1N1 viruses in BALB/cJ mice, and 1 of 2 strains transmitted both by direct and respiratory-droplet contact in ferrets. Preliminary studies of other avian subtypes (H2, H3, H4, H6, H10, H12) in DBA/2J mice showed lower pathogenicity than the avian H1N1 viruses. These findings suggest that avian H1N1 influenza viruses are unique among influenza A viruses in their potential to infect mammals.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Female
  • Ferrets / virology
  • Influenza A Virus, H1N1 Subtype / pathogenicity
  • Influenza A Virus, H1N1 Subtype / physiology*
  • Mice
  • Orthomyxoviridae Infections / transmission
  • Orthomyxoviridae Infections / virology*
  • Species Specificity
  • Viral Load
  • Virus Replication*