The first identified case of pandemic H1N1 influenza in pigs in Australia

Aust Vet J. 2011 Nov;89(11):427-31. doi: 10.1111/j.1751-0813.2011.00844.x.


A 300-sow farrow-to-finish herd in New South Wales was infected with influenza pandemic (H1N1) 2009 (H1N1/09) virus in July 2009 and became the first recorded case of influenza in pigs in Australia. The outbreak resulted from human-to-pig transmission. Clinical signs in affected pigs were mild compared with overseas reports of 'classical' swine influenza virus and included coughing and decreased appetite in a small proportion of non-lactating breeding stock, weaners, growers and finishers. A diagnosis of H1N1/09 influenza virus infection was confirmed using a combination of serology (haemagglutination inhibition, blocking enzyme-linked immunosorbent assay) and real-time reverse transcription polymerase chain reaction. Attempts at virus isolation were unsuccessful. Results of a longitudinal study of pigs on this farm suggested that the virus continued to circulate for 9 weeks after the onset of infection, but was not present 6 months later. This report highlights the difficulties in preventing transmission of H1N1/09 influenza virus from infected humans to pigs during a human pandemic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Australia / epidemiology
  • Disease Outbreaks / veterinary
  • Female
  • Humans
  • Influenza A Virus, H1N1 Subtype*
  • Influenza, Human / epidemiology*
  • Influenza, Human / prevention & control
  • Influenza, Human / transmission
  • Male
  • Orthomyxoviridae Infections / epidemiology
  • Orthomyxoviridae Infections / prevention & control
  • Orthomyxoviridae Infections / transmission
  • Orthomyxoviridae Infections / veterinary*
  • Swine
  • Swine Diseases / epidemiology*
  • Swine Diseases / prevention & control
  • Swine Diseases / transmission
  • Zoonoses*