National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2011

09. Potential emergence of a novel influenza virus from pigs in Southeast Asia


Little is known about swine influenza viruses (SIVs) in Southeast Asia, although the emergence of the A(H1N1)pdm09 virus—an SIV reassortant—has raised concerns about SIVs and public health. We collected 759 and 731 nasal swabs from pigs in Vietnam in 2010 and Thailand from 2008 to 2009, respectively. H3N2 SIVs with a novel genetic constellation was isolated in Vietnam. They were a reassortant of a human epidemic strain and a swine triple reassortant, the constellation of which has not been recognized in any other place in the world. Nine H1N1, 2 H3N2, and A(H1N1)pdm09 viruses were isolated in Thailand during the collection period. The isolation rate was high in piglets on farms in Thailand with farrow-to-finish operations. This study is the first to isolate SIVs in Vietnam, and the discovery of an SIV with a novel genotype highlights genetic diversity of SIVs in the region. Monitoring SIVs in Southeast Asia would contribute not only to animal health but also to public health sectors.
(Viral Disease and Epidemiology Research Division)


  • Ngo L. T. et al (2011) Influenza Other Respi. Viruses 6(1):6-10 
  • Takemae N. et al (2011) Virol. J. 8:537 (DOI:10.1186/1743-422X-8-537)