United States - 2 new outbreaks of highly pathogenic avian influenza H5N8 in birds (OIE, May 21, 2015)

[Pathfinder]

Highly pathogenic avian influenza, United States of America

Information received on 21/05/2015 from Dr John Clifford, Deputy Administrator, Animal and Plant Health Inspection Service, United States Department of Agriculture, Washington, United States of America

Summary Report type Follow-up report No. 13 Date of start of the event 10/12/2014 Date of confirmation of the event 14/12/2014 Report date 21/05/2015 Date submitted to OIE 21/05/2015 Reason for notification Reoccurrence of a listed disease Date of previous occurrence 2004 Manifestation of disease Clinical disease Causal agent Highly pathogenic avian influenza virus 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)

New outbreaks (2)

Outbreak 1 Siskiyou County, Siskiyou, CALIFORNIA Date of start of the outbreak 10/01/2015 Outbreak status Resolved (10/04/2015) Epidemiological unit Not applicable Affected animals Species Susceptible Cases Deaths Destroyed Slaughtered American wigeon:Anas americana(Anatidae) Affected population Wild bird surveillance.

Outbreak 2 Whitley County, Whitley, INDIANA Date of start of the outbreak 08/05/2015 Outbreak status Continuing (or date resolved not provided) Epidemiological unit Backyard Affected animals Species Susceptible Cases Deaths Destroyed Slaughtered Birds 77 10 10 67 0 Affected population The affected premises was a small mixed backyard poultry flock of chickens, turkeys, ducks, and geese.

Summary of outbreaks Total outbreaks: 2 Total animals affected Species Susceptible Cases Deaths Destroyed Slaughtered American wigeon:Anas americana(Anatidae) ** Birds 77 10 10 67 0 Outbreak statistics Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost* American wigeon:Anas americana(Anatidae) ** ** ** ** Birds 12.99% 12.99% 100.00% 100.00% *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 and H5N2 wild bird related events. Novel avian influenza virus of Eurasian origin (EA-H5N8 clade 2.3.4.4) spread 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 the 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. The HPAI identified in a backyard flock in Whitley County, Indiana is the first detection of H5N8 HPAI in the Mississippi flyway, which parallels and overlaps largely with the Central flyway, and is the first detection of HPAI in Indiana. Together with the Indiana State Departments of Agriculture and Wildlife, USDA APHIS is conducting an epidemiological investigation and enhanced surveillance in response to this HPAI H5N8 event. To date, all testing results from the enhanced surveillance have been negative for avian influenza and the HPAI virus has not been found in commercial poultry anywhere in Indiana.

Control measures Measures applied Quarantine Movement control inside the country Zoning Disinfection of infected premises/establishment(s) Modified 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) 08/05/2015 Positive National Veterinary Services Laboratories (NVSL) (National laboratory) American wigeon virus sequencing 08/05/2015 Positive National Veterinary Services Laboratories (NVSL) (National laboratory) Birds real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 10/05/2015 Positive National Veterinary Services Laboratories (NVSL) (National laboratory) Birds virus sequencing 10/05/2015 Positive

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

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