Highly pathogenic avian influenza,
United States of America
Information received on 22/01/2015 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
Summary
Report type Follow-up report No. 4
Date of start of the event 10/12/2014
Date of confirmation of the event 14/12/2014
Report date 22/01/2015
Date submitted to OIE 22/01/2015
Date event resolved 22/07/2015
Reason for notification Recurrence of a listed disease
Date of previous occurrence 2004
Manifestation of disease Clinical disease
Causal agent Highly pathogenic avian influenza
Serotype H5N8
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 (19/12/2014)
Follow-up report No. 2 (29/12/2014)
Follow-up report No. 3 (07/01/2015)
Follow-up report No. 4 (22/01/2015)
Follow-up report No. 5 (25/01/2015)
Follow-up report No. 6 (03/02/2015)
Follow-up report No. 7 (13/02/2015)
Follow-up report No. 8 (25/02/2015)
Follow-up report No. 9 (05/03/2015)
Follow-up report No. 10 (20/03/2015)
Follow-up report No. 11 (31/03/2015)
Follow-up report No. 12 (22/04/2015)
Follow-up report No. 13 (21/05/2015)
Follow-up report No. 14 (09/06/2015)
Follow-up report No. 15 (16/06/2015)
Follow-up report No. 16 (22/07/2015)
Follow-up report No. 17 (17/08/2015)
New outbreaks (4)
Outbreak 1 Butte County, Butte, CALIFORNIA
Date of start of the outbreak 02/01/2015
Outbreak status Resolved (02/04/2015)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Gadwall:Anas strepera(Anatidae)
Affected population Hunter harvested wild gadwall duck
Outbreak 2 Davis County, Davis, UTAH
Date of start of the outbreak 09/01/2015
Outbreak status Resolved (09/04/2015)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
American wigeon:Anas americana(Anatidae)
Affected population Hunter harvested wild American wigeon duck.
Outbreak 3 Yolo county, Yolo, CALIFORNIA
Date of start of the outbreak 09/01/2015
Outbreak status Resolved (09/04/2015)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Green-winged Teal:Anas carolinensis(Anatidae)
Affected population Hunter harvested wild American green-winged teal duck.
Outbreak 4 Gooding County, Gooding, IDAHO
Date of start of the outbreak 16/01/2015
Outbreak status Resolved (16/04/2015)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Mallard:Anas platyrhynchos(Anatidae)
Affected population Hunter harvested wild mallard duck
Summary of outbreaks Total outbreaks: 4
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Gadwall:Anas strepera(Anatidae) **
American wigeon:Anas americana(Anatidae) **
Green-winged Teal:Anas carolinensis(Anatidae) **
Mallard:Anas platyrhynchos(Anatidae) **
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Gadwall:Anas strepera(Anatidae) ** ** ** **
American wigeon:Anas americana(Anatidae) ** ** ** **
Green-winged Teal:Anas carolinensis(Anatidae) ** ** ** **
Mallard:Anas platyrhynchos(Anatidae) ** ** ** **
*Removed from the susceptible population through death, destruction and/or slaughter
**Not calculated because of missing information
Epidemiology
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 (including wild bird surveillance of hunter harvested birds) in response to the HPAI H5N8 wild bird related event. Novel avian influenza virus of Eurasian origin (EA-H5N8 clade 2.3.4.4) spread rapidly along wild bird migratory pathways during 2014. Introduction of this EA-H5N8 virus into the Pacific Flyway sometime during 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 this EA/AM H5N2-reassortant detected in Canada and the US. These findings are not unexpected as the EA-H5N8 virus continues to circulate. The EA H5 clade 2.3.4.4 viruses are highly pathogenic for poultry. As part of the increased AI surveillance of wild birds (performed by testing hunter harvested birds), H5N8 with an amino acid sequence at the HA cleavage site that is consistent with highly pathogenic avian influenza has been identified in wild ducks in the Pacific flyway. HA and NA sequence fragments from these viruses, and the virus from the backyard finding, are essentially identical to that found in the reported gyrfalcon. Update on the Oregon backyard premises as of 17 January 2015: • A 10 km active surveillance zone was initiated for avian influenza. o All surveillance and testing has been negative for AI. The HPAI EA-H5N8 virus has NOT been found in commercial poultry anywhere in the United States.
Control measures
Measures applied
  • Movement control inside the country
  • Disinfection / Disinfestation
  • Quarantine
  • Stamping out
  • 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) American wigeon real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 09/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Gadwall real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 02/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Gadwall virus sequencing 02/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Green-winged Teal real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 09/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Green-winged Teal virus sequencing 09/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Mallard real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 16/01/2015 Positive
National Veterinary Services Laboratories (NVSL) (National laboratory) Mallard virus sequencing 16/01/2015 Positive
NationalVeterinary Services Laboratories (NVSL) (National laboratory) American wigeon virus sequencing 09/01/2015 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations