Highly pathogenic avian influenza,
United States of America
Information received on 07/01/2015 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 Follow-up report No. 1
Date of start of the event 10/12/2014
Date of confirmation of the event 15/12/2014
Report date 07/01/2015
Date submitted to OIE 07/01/2015
Date event resolved 13/11/2015
Reason for notification Recurrence of a listed disease
Date of previous occurrence 2004
Manifestation of disease Clinical disease
Causal agent Highly pathogenic avian influenza virus
Serotype H5N2
Nature of diagnosis Laboratory (advanced)
This event pertains to a defined zone within the country
Related reports Immediate notification (16/12/2014)
Follow-up report No. 1 (07/01/2015)
Follow-up report No. 2 (13/01/2015)
Follow-up report No. 3 (22/01/2015)
Follow-up report No. 4 (03/02/2015)
Follow-up report No. 5 (17/02/2015)
Follow-up report No. 6 (24/02/2015)
Follow-up report No. 7 (06/03/2015)
Follow-up report No. 8 (12/03/2015)
Follow-up report No. 9 (20/03/2015)
Follow-up report No. 10 (31/03/2015)
Follow-up report No. 11 (08/04/2015)
Follow-up report No. 12 (15/04/2015)
Follow-up report No. 13 (24/04/2015)
Follow-up report No. 14 (01/05/2015)
Follow-up report No. 15 (08/05/2015)
Follow-up report No. 16 (20/05/2015)
Follow-up report No. 17 (29/05/2015)
Follow-up report No. 18 (09/06/2015)
Follow-up report No. 19 (17/06/2015)
Follow-up report No. 20 (26/06/2015)
Follow-up report No. 21 (02/07/2015)
Follow-up report No. 22 (22/07/2015)
Follow-up report No. 23 (31/07/2015)
Follow-up report No. 24 (10/08/2015)
Follow-up report No. 25 (17/08/2015)
Follow-up report No. 26 (24/08/2015)
Follow-up report No. 27 (01/09/2015)
Follow-up report No. 28 (08/09/2015)
Follow-up report No. 29 (14/09/2015)
Follow-up report No. 30 (21/09/2015)
Follow-up report No. 31 (07/10/2015)
Follow-up report No. 32 (13/10/2015)
Follow-up report No. 33 (13/11/2015)
Follow-up report No. 34 (18/11/2015)
New outbreaks (1)
Outbreak 1 ( 3) Benton County, Benton, Washington
Date of start of the outbreak 24/12/2014
Outbreak status Resolved (08/04/2015)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 253 37 37 216 0
Affected population The affected premises was a small backyard mixed free-range flock of geese, turkeys, chickens, ducks, and pigeons that were allowed access to the outdoors and regularly exposed to wild migratory waterfowl. The affected premises also included a related epidemiology linked backyard flock that received birds (ducks) from the index flock.
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 253 37 37 216 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds 14.62% 14.62% 100.00% 100.00%
*Removed from the susceptible population through death, destruction and/or slaughter
Source of the outbreak(s) or origin of infection
  • Contact with wild species
Epidemiological comments The USDA Animal and Plant Health Inspection Service (APHIS), in conjunction with State Departments of Agriculture and Wildlife, are continuing to conduct a comprehensive epidemiological investigation and enhanced surveillance in response to the HPAI H5N2 wild bird related event. The USDA APHIS National Veterinary Services Laboratory (NVSL) confirmed avian influenza virus (AIV) H5N2 in a backyard mixed flock. Preliminary results indicate that the H5N2 identified is 99% similar to the recent H5N2 isolated from the Northern pintail duck. Epidemiological investigation of backyard AIV infected premises as of 6 January 2015: Two high risk epidemiologically linked contact backyard premises have been identified and placed under quarantine. Biological sampling for AIV has been completed and results are pending. Enhanced surveillance in a 10 km radius has been implemented. The HPAI H5N2 virus has NOT been found in commercial poultry anywhere in the United States.
Control measures
Measures applied
  • Movement control inside the country
  • Quarantine
  • Stamping out
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • Disinfection / Disinfestation
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Veterinary Services Laboratory (NVSL) (National laboratory) Birds real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 03/01/2015 Positive
National Veterinary Services Laboratory (NVSL) (National laboratory) Birds virus isolation Pending
National Veterinary Services Laboratory (NVSL) (National laboratory) Birds virus sequencing 03/01/2015 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations