Tropism of avian influenza A (H5N1) in the upper and lower respiratory tract

Nat Med. 2007 Feb;13(2):147-9. doi: 10.1038/nm1529. Epub 2007 Jan 7.


Poor human-to-human transmission of influenza A H5N1 virus has been attributed to the paucity of putative sialic acid alpha2-3 virus receptors in the epithelium of the human upper respiratory tract, and thus to the presumed inability of the virus to replicate efficiently at this site. We now demonstrate that ex vivo cultures of human nasopharyngeal, adenoid and tonsillar tissues can be infected with H5N1 viruses in spite of an apparent lack of these receptors.

Publication types

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

MeSH terms

  • Cells, Cultured
  • Epithelium / virology
  • Histocytochemistry
  • Hong Kong
  • Humans
  • Influenza A Virus, H1N1 Subtype / metabolism
  • Influenza A Virus, H3N2 Subtype / metabolism
  • Influenza A Virus, H5N1 Subtype / metabolism*
  • Influenza, Human / metabolism
  • Influenza, Human / transmission*
  • Phytohemagglutinins / metabolism
  • Receptors, Cell Surface / metabolism*
  • Respiratory System / virology*
  • Virus Attachment*
  • Virus Replication / physiology


  • Phytohemagglutinins
  • Receptors, Cell Surface
  • leukoagglutinins, plants
  • sialic acid receptor