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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #323423
Title: Highly pathogenic Eurasian H5N8 avian influenza outbreaks in two commercial poultry flocks in California

Author
item STOUTE, SIMONE - California Animal Health & Food Laboratory
item CHIN, RICHARD - California Animal Health & Food Laboratory
item CROSSLEY, BEATE - California Animal Health & Food Laboratory
item SENTIES-CUE, GABRIEL - California Animal Health & Food Laboratory
item BICKFORD, ARTHUR - California Animal Health & Food Laboratory
item Pantin Jackwood, Mary
item BREITMEYER, RICHARD - California Animal Health & Food Laboratory
item JONES, ANNETTE - California Animal Health & Food Laboratory
item CARNACCINI, SILVIA - California Animal Health & Food Laboratory
item SHIVAPASAD, H - California Animal Health & Food Laboratory

Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2016
Publication Date: 9/1/2016
Citation: Stoute, S., Chin, R., Crossley, B., Senties-Cue, G., Bickford, A., Pantin Jackwood, M.J., Breitmeyer, R., Jones, A., Carnaccini, S., Shivapasad, H.L. 2016. Highly pathogenic Eurasian H5N8 avian influenza outbreaks in two commercial poultry flocks in California. Avian Diseases. 60(3):688-693. doi:10.1637/11314-110615-Case.1.

Interpretive Summary: A highly pathogenic Eurasian lineage H5N8 avian influenza (AI) virus was detected in a commercial meat turkey flock, and in commercial chickens in California, in January of 2015. Five, 14-week-old turkey hens, and eleven 12-week-old chickens were submitted to diagnostic laboratories due to an acute increase in flock mortality. Birds had enlarged and mottled pale spleens and pancreas. Microscopically, the major lesions observed were splenitis, pancreatitis, encephalitis, and pneumonia. Diagnosis was based on virus molecular detection from cloacal and pharyngeal swabs, sequencing, and virus isolation. Confirmatory diagnosis and AI virus characterization was done at the National Veterinary Services Laboratory (NVSL), Ames, Iowa. The AI virus isolated from both cases was 99% identical to an H5N8 AI virus (A/gyrfalcon/Washington/41088-6/2014) isolated in Washington State in December 2014. Immunohistochemistry performed on various tissues to detect virus antigen indicated widespread tissue distribution and was similar in the chickens and turkeys.

Technical Abstract: In January 2015, a highly pathogenic Eurasian lineage H5N8 avian influenza (AI) virus was detected in a commercial meat turkey flock in Stanislaus County, California. Approximately 3 weeks later, a similar case was diagnosed in commercial chickens from a different company located in Kings County, California. Five, 14-week-old turkey hens were submitted to the California Animal Heath and Food Safety Laboratory System (CAHFS), Turlock, and eleven, 12-week-old chickens were submitted to CAHFS, Tulare, laboratories due to an acute increase in flock mortality. Gross lesions included enlarged and mottled pale spleens and pancreas in turkeys and chickens. Histologically, the major lesions observed in turkeys and chickens were splenitis, pancreatitis, encephalitis, and pneumonia. In both cases, diagnosis was based on real time reverse transcriptase polymerase chain reaction (RT-PCR) from cloacal and pharyngeal swabs, sequencing, and virus isolation. Confirmatory diagnosis and AI virus characterization was done at the National Veterinary Services Laboratory (NVSL), Ames, Iowa. The AI virus isolated from both cases was 99% identical to an H5N8 AI virus (A/gyrfalcon/Washington/41088-6/2014) isolated from a captive gyrfalcon from Washington State in December 2014. Immunohistochemistry (IHC) performed on various tissues from both cases indicated a widespread AI virus tissue distribution. Except for minor variations, the AI antigen tissue distribution was similar in the chickens and turkeys. There was positive IHC staining in brain, spleen, pancreas, larynx, trachea, lungs, and air sacs in both chickens and turkeys. The liver sections from the chickens had occasional AI positive staining in mononuclear cells, but the IHC on liver sections from the turkeys were negative. The bursa of Fabricius, small intestine, pharynx. and skeletal muscle sections were negative for AI antigen in both chickens and turkeys.