The first identified case of pandemic H1N1 influenza in pigs in Australia.
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.
Industry and Investment, Wagga Wagga Agricultural Institute, New South Wales, Australia. trish.holyoake@dpi.vic.gov.au
P K
PK
Holyoake
P D
PD
Kirkland
R J
RJ
Davis
K E
KE
Arzey
J
J
Watson
R A
RA
Lunt
J
J
Wang
F
F
Wong
B J
BJ
Moloney
S E
SE
Dunn
D000818:Animals; D001315:Australia / Q000453:epidemiology; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D008297:Male; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D015047:Zoonoses