Highly pathogenic avian influenza,
United States of America
Information received on 20/01/2015 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 Immediate notification
Date of start of the event 16/01/2015
Date of confirmation of the event 16/01/2015
Report date 20/01/2015
Date submitted to OIE 20/01/2015
Date event resolved 05/06/2015
Reason for notification Recurrence of a listed disease
Date of previous occurrence 2004
Manifestation of disease Sub-clinical infection
Causal agent Highly pathogenic avian influenza virus
Serotype H5N1
Nature of diagnosis Laboratory (advanced)
This event pertains to a defined zone within the country
Related reports Immediate notification (20/01/2015)
Follow-up report No. 1 (03/02/2015)
Follow-up report No. 2 (13/02/2015)
Follow-up report No. 3 (25/02/2015)
Follow-up report No. 4 (05/03/2015)
Follow-up report No. 5 (20/03/2015)
Follow-up report No. 6 (08/04/2015)
Follow-up report No. 7 (15/04/2015)
Follow-up report No. 8 (09/06/2015)
Follow-up report No. 9 (16/06/2015)
New outbreaks (1)
Outbreak 1 Whatcom County, Whatcom, Washington
Date of start of the outbreak 16/01/2015
Outbreak status Resolved (15/04/2015)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Green-winged Teal:Anas carolinensis(Anatidae)
Affected population Wild American green-winged teal duck
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Green-winged Teal:Anas carolinensis(Anatidae) **
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Green-winged Teal:Anas carolinensis(Anatidae) ** ** ** **
*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
  • Contact with wild species
Epidemiological comments As part of the increased AI surveillance of wild birds (performed by testing hunter harvested birds), another Eurasian H5 clade virus has been identified through whole genome sequencing of the virus isolate. Introduction of the Eurasian (EA) H5N8 virus into the Pacific Flyway sometime during late 2014 has allowed mixing with North American (AM) lineage viruses and generated new combinations with genes from both EA and AM origin (or “reassortant” viruses) such as the EA/AM H5N2-reassortant detected in Canada and the United States. Such findings are not unexpected as the EA-H5N8 virus continues to circulate. A novel EA/AM H5N1-reassortant clade was isolated from an American green-winged teal in Whatcom County, Washington. This H5N1 subtype is different from strain circulating in Asia. The gene constellation is as follows: Eurasian lineage genes (PB2, H5, NP, MP >99% identical to A/gyrfalcon/WA/41088/2014 H5N8); North American lineage genes (PB1 {98% identical to A/Northern pintail/Washington/40964/2014 H5N2}, PA, N1, NS of North American LPAI wild bird lineage. The HA cleavage site is compatible with strains that are highly pathogenic. This novel HPAI EA/AM H5N1-reassortant virus has NOT been found in commercial poultry anywhere in the United States.
Control measures
Measures applied
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • No other measures
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Veterinary Services Laboratories (NVSL) (National laboratory) Green-winged Teal gene sequencing 16/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Green-winged Teal real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 16/01/2015 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations