Influenza A subtype H1,
Australia

Information received on 31/07/2009 from Dr Andy Carroll, Chief Veterinary Officer , Department of Agriculture, Fisheries and Forestry, Australian Government , Canberra, Australia

Summary

Report type Immediate notification
Start date 24/07/2009
Date of first confirmation of the event 31/07/2009
Report date 31/07/2009
Date submitted to OIE 31/07/2009
Date event resolved 13/08/2009
Reason for notification Emerging disease
Morbidity 5 %
Mortality 0 %
Zoonotic impact People associated with the piggery had shown influenza-like illness prior to this incident
Causal agent Influenza A H1 subtype
Related reports

New outbreaks
Outbreak 1 Central West New South Wales, NEW SOUTH WALES
Date of start of the outbreak 24/07/2009
Outbreak status Resolved (13/08/2009)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Destroyed Slaughtered
Swine 1950 100 0 0 0
Affected Population Integrated farrow-to-finish farm; finishers had mild cough, weaners less affected.
Summary of outbreaks Total outbreaks: 1
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Swine 5.13% 0.00% 0.00% 0.00%

* Removed from the susceptible population through death, destruction and/or slaughter

Epidemiology
Source of the outbreak(s) or origin of infection
  • Most likely, contact with people
Epidemiological comments This is the first outbreak of influenza in swine in Australia.
The affected farm is isolated. It is a mixed farming operation, raising both cattle and sheep (separated from the piggery). There is no poultry nearby. There has been no introduction of live pigs for more than 2 years. The property has been placed under quarantine.
Disease has been very mild in affected pigs. 12 of 13 clinical cases sampled gave a positive result to the Influenza A matrix qPCR, with one indeterminate result. 9 of 13 animals gave a positive result to a H1 specific qPCR, with 4 indeterminate results.
Epidemiological investigations are continuing. Further work is under way to isolate virus and sequence PCR material.

Control measures
Measures applied
  • Quarantine
  • Movement control inside the country
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • No other measures

Diagnostic test results
Laboratory name and type Elizabeth Macarthur Agricultural Institute (Local laboratory)
Tests and results
Species Test Test date Result
Swine enzyme-linked immunosorbent assay (ELISA) 31/07/2009 Positive
Swine haemagglutination inhibition test (HIT) 31/07/2009 Positive
Swine real-time PCR 31/07/2009 Positive
Laboratory name and type Australian Animal Health Laboratory (National laboratory)
Tests and results
Species Test Test date Result
Swine enzyme-linked immunosorbent assay (ELISA) 31/07/2009 Positive
Swine haemagglutination inhibition test (HIT) 31/07/2009 Positive
Swine real-time PCR 31/07/2009 Positive

Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.

Map of outbreak locations
Location of current outbreaks

Click on map to zoom in.