As a precaution and in response to the recent HPAI outbreak in Canada, surveillance of poultry premises and of wild bird mortality events was enhanced by the USDA, and State personnel along the US-Canadian border.

Through this surveillance, highly pathogenic avian influenza (HPAI) H5 was identified in wild birds.

Two serotypes were identified on enhanced surveillance, both with amino acid sequence at the HA cleavage site consistent with HPAI, H5N8 and H5N2.

H5N8 was identified in a captive wild gyrfalcon that was fed hunter killed wild birds from Whatcom County, Washington and H5N2 was identified in a wild pintail duck also from Whatcom County, Washington.

Preliminary analysis suggests this H5N2 is similar to the HPAI identified in the current Canadian outbreak.

Based upon sequence attempt from a virus isolate, an avian influenza subtype H5 of Eurasian lineage (partial HA 98 per cent similarity to A/bean goose/Korea/H40/2014) and N2 of US wild bird lineage (partial NA 98 per cent similarity to A/American green-winged teal/California/HKWF609/2007); the amino acid sequence at the hemagglutinin cleavage site is consistent with highly pathogenic avian influenza (HPAI).

Preliminary data suggests that these virus strains (H5N2 and H5N8) may be related with the H5N8 strain potentially representing the progenitor; however further analysis is needed.

Neither of these viruses has been found in any poultry in the United States. These H5N8 and H5N2 detections involve only wild birds. Further investigation and characterisation of the HPAI viruses is ongoing.

Further Reading

You can visit the Avian Flu page by clicking here.