Further evidence for infection of pigs with human-like H1N1 influenza viruses in China

Virus Res. 2009 Mar;140(1-2):85-90. doi: 10.1016/j.virusres.2008.11.008. Epub 2009 Jan 3.

Abstract

Classical swine and avian-like H1N1 influenza viruses were reported widely in swine population worldwide, but human-like H1N1 swine viruses were reported occasionally. In 2006, a human-like H1N1 swine virus (A/swine/Guangdong/96/06) was isolated from pigs in Guangdong province, which was reported in China for the first time. To get further evidence for infection of pigs with human-like H1N1 influenza viruses, we analyzed eight gene segments of three human-like swine H1N1 viruses (A/swine/Guangdong/96/06, A/swine/Tianjin/01/04 and A/swine/Henan/01/06) isolated in China. All the eight genes of the three viruses are highly homologous to recent (about 2000) and early (1980s) human H1N1 influenza viruses, respectively. Phylogenetic analyses revealed that A/Swine/Guangdong/96/06 was directly derived from about 2000 human H1N1 influenza viruses, while A/swine/Tianjin/01/04 and A/swine/Henan/01/06 seemed to be descendants of human H1N1 viruses circulating in 1980s. Seroprevalence of our isolate (A/swine/Guangdong/96/06) confirmed the presence of human-like H1N1 virus in pigs in China. Existence of these influenza viruses, especially older viruses (A/swine/Tianjin/01/04 and A/swine/Henan/01/06), indicates that human-like H1N1 influenza viruses may remain invariant for long periods in pigs and provides the evidence that pigs serve as reservoirs of older influenza viruses for human pandemics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Viral / blood
  • China / epidemiology
  • Evolution, Molecular
  • Genes, Viral
  • Humans
  • Influenza A Virus, H1N1 Subtype / genetics*
  • Influenza A Virus, H1N1 Subtype / isolation & purification
  • Influenza A Virus, H1N1 Subtype / pathogenicity
  • Molecular Sequence Data
  • Orthomyxoviridae Infections / epidemiology
  • Orthomyxoviridae Infections / veterinary*
  • Orthomyxoviridae Infections / virology
  • Phylogeny*
  • RNA, Viral / genetics
  • Sequence Alignment
  • Sequence Analysis, RNA
  • Sequence Homology, Nucleic Acid
  • Seroepidemiologic Studies
  • Swine / virology*
  • Swine Diseases / epidemiology*
  • Swine Diseases / virology

Substances

  • Antibodies, Viral
  • RNA, Viral