Veterinary Services
Centers for Epidemiology and Animal Health
August 29, 2007
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Short Report
Equine Influenza in Australia
Background
Outbreaks of equine influenza (EI) occur regularly
throughout most countries of the world. Prior to the
current outbreak in Australia, Iceland, New Zealand and
Australia were the only countries that had never reported
the occurrence of EI. EI is the most frequently diagnosed
and economically important cause of viral respiratory
disease of horses. Because EI is an ongoing risk among
horses that co-mingle (shows, races, sales), vaccination
to prevent disease is commonly employed in the United
States. Equine influenza is not a human pathogen, but
the virus can be transported on people’s clothing, hands,
or equipment. In 2004 in the United States, a strain of
equine influenza A H3N8 virus caused a major outbreak
of influenza in canines.
Sources:
1) Equine Influenza Infection. 2007. Landolt, G.A.; Townsend,
H.G.G.; Lunn, P. In: Equine Infectious Diseases. Sellon, D.C.;
Long, M.T. (eds.). Elsevier Inc.
2) Equine 2005. National Animal Health Monitoring System.
http://nahms.aphis.usda.gov.
3) Landolt, G.A. 2006. Review of Interspecies Transmission of
Influenza A Viruses: Implications for the Equine Population,
AAEP Proceedings, vol. 52.
Outbreak Summary
On August 25, 2007, Australian government authorities
reported to the OIE an outbreak of equine influenza (EI).
This is the first occurrence of EI in Australia. EI H3 was
first detected on August 17 at the Eastern Creek
Quarantine Station in Sydney, New South Wales (NSW)
and confirmed on August 20. On August 22 horses at
the Centennial Parklands Equestrian Centre in Sydney
displayed clinical signs consistent with EI, and
subsequently tested positive for EI H3. Since these initial
two detections, EI has been found at additional locations
in NSW and in