Low pathogenic avian influenza (poultry),
United States of America
Information received on 12/09/2018 from Dr John Clifford, Official Delegate, Chief Trade Advisor, Animal and Plant Health Inspection Service, United States Department of Agriculture, Washington, United States of America
Report type Immediate notification
Date of start of the event 06/09/2018
Date of confirmation of the event 08/09/2018
Report date 12/09/2018
Date submitted to OIE 12/09/2018
Date event resolved 01/07/2019
Reason for notification Recurrence of a listed disease
Date of previous occurrence 30/04/2018
Manifestation of disease Sub-clinical infection
Causal agent Low pathogenic avian influenza virus
Serotype H7N3
Nature of diagnosis Laboratory (advanced)
This event pertains to a defined zone within the country
Related reports Immediate notification (12/09/2018)
Follow-up report No. 1 (19/09/2018)
Follow-up report No. 2 (25/09/2018)
Follow-up report No. 3 (12/10/2018)
Follow-up report No. 4 (08/07/2019)
New outbreaks (1)
Outbreak 1 ( Stanislaus 1) Stanislaus County, Stanislaus, California
Date of start of the outbreak 06/09/2018
Outbreak status Resolved (15/01/2019)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 26258 26258 0
Affected population Commercial meat-type turkey flock
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 26258 ** 26258 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds ** ** ** **
*Removed from the susceptible population through death, destruction and/or slaughter
**Not calculated because of missing information
Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
Epidemiological comments As part of the pre-slaughter testing and surveillance program for H5/H7 Avian Influenza, H7N3 low pathogenic avian influenza (LPAI) was detected in a commercial meat-type turkey flock. Partial HA /NA sequencing determined the H7 and N3 to be a low pathogenic virus of North American wild bird lineage. Further characterization is pending virus recovery. The affected flock was depopulated and the carcasses have been rendered. The USDA Animal Plant Health Inspection Service (APHIS) and the California Department of Food and Agriculture (CDFA) are conducting an epidemiological investigation of the event and have increased testing as a result of the detection. Ten additional commercial poultry premises located within the 10km zone are being tested for influenza virus.
Control measures
Measures applied
  • Movement control inside the country
  • Surveillance outside containment and/or protection zone
  • Surveillance within containment and/or protection zone
  • Quarantine
  • Stamping out
  • Zoning
  • Vaccination permitted (if a vaccine exists)
  • No treatment of affected animals
Measures to be applied
  • Disinfection
Diagnostic test results
Laboratory name and type Species Test Test date Result
California Animal Health & Food Safety Laboratory (Local laboratory) Birds agar-gel precipitation (AGP) test 06/09/2018 Positive
National Veterinary Services Laboratory (National laboratory) Birds real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 08/09/2018 Positive
National Veterinary Services Laboratory (National laboratory) Birds virus sequencing Pending
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations