Study of an #Outbreak of Highly Pathogenic #Avian #Influenza #H5N8 in Commercial Pekin #Ducks ( Anas platyrhynchos domesticus) in #California (Avian Dis., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Avian Dis. 2018 Mar;62(1):101-108. doi: 10.1637/11773-112017-Reg.1.

Study of an Outbreak of Highly Pathogenic Avian Influenza H5N8 in Commercial Pekin Ducks ( Anas platyrhynchos domesticus) in California.

Stoute S1, Crossley B2, Shivaprasad HL3.

Author information: 1 A California Animal Health & Food Safety Laboratory System, Turlock Branch, 1550 N. Soderquist Road, Turlock, CA 95381. 2 B California Animal Health & Food Safety Laboratory System, Davis Branch, One Shields Avenue, Davis, CA 95616. 3 C California Animal Health & Food Safety Laboratory System, Tulare Branch, 18830 Road 112, Tulare, CA 93274.



A February 2015 outbreak of highly pathogenic avian influenza (HPAI) H5N8 in a flock of commercial Pekin ducks ( Anas platyrhynchos domesticus) in California was investigated in detail. Approximately 17,349 five-wk-old ducks experienced an increased mortality from a normal of eight birds per day to 24, 18, 24, 33, and 61 birds per day, respectively, in the last 5 days prior to flock depopulation. Clinically, there was decreased water and feed consumption, and approximately 1.0% of the affected flock exhibited neurologic signs. Necropsy of five clinically ill ducks revealed pale, patchy areas on the epicardium in two birds, pale foci of necrosis in the liver of one bird, and airsacculitis in three birds. Histopathology revealed multifocal nonsuppurative encephalomyelitis, myocarditis, myositis, pancreatitis, hepatitis, and glossitis. Immunohistochemistry revealed avian influenza virus (AIV) nucleoprotein in the nucleus and cytoplasm of various cells in the aforementioned organs, as well as in the skin and feathers. Eight of the 10 sera samples tested were positive for avian influenza antibodies by agar gel immunodiffusion serology. Oropharyngeal and cloacal swabs taken from 15 birds, as well as from the lungs, livers, pancreas, and spleen, were positive for AIV by real-time reverse transcriptase (rRT) PCR. AIV was isolated and typed as Eurasian lineage HPAI H5N8, clade, by the National Veterinary Services Laboratory, Ames, IA. Extensive surveillance of birds for AIV around the 10-km zone did not reveal any additional cases. Ducks on the affected premises were humanely euthanatized by foam and composted in-house, the houses were heated to 57 C for 4 days, and swabs were taken periodically from the compost to ensure negativity for AIV by rRT-PCR. The compost and litter were then removed, and the house was pressure cleaned, disinfected, and repopulated approximately 120 days after euthanatization of the ducks.

KEYWORDS: California; Pekin; avian influenza; commercial; ducks; highly pathogenic; immunohistochemistry; pathology; serology; virus isolation

PMID: 29620470 DOI: 10.1637/11773-112017-Reg.1

Keywords: Avian Influenza; H5N8; Poultry; USA; California.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum ( in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.