Flock characteristics at farms with avian influenza H5N1 in 2021/2022


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Flock characteristics at farms with avian influenza H5N1 in 2021/2022


At the time of writing, 28 and 35 NVWA specialist team visits had been conducted due to suspicion of avian influenza (AI) in the fourth quarter of 2021 and first quarter of 2022, respectively. Table 1 gives an overview of the past history of the flocks at the poultry farms visited by the specialist team, whereby the PCR test was positive for AI type H5. It also indicates which clinical abnormalities were detected and which abnormalities were found upon necropsy.

There was no production drop in layers in the days prior to testing, and there was only a slight decrease in feed and water intake. The cases were reported mainly because of increased losses in a specific section of the house. No specific abnormalities were found at necropsy, yet lesions of diverse origin could be found. The necropsy results were often ‘negative’, showing only local and random haemorrhage in some animals. Localised increased losses were also the reason for reporting in broilers and turkeys, as well as a limited number of seriously ill animals, again with lesions of diverse origin and often ‘negative’ necropsy results. In the case of ducks, a serious decrease in feed and water intake suggested the presence of the H5N1 virus. The AI PCR was negative in the duck cases of increased losses without decreased feed intake.

More Monitoring Animal Health
This newsitem is published in Monitoring Animal Health Poultry of April 2022.
Other subjects:

  • Increase in clinical outbreaks of M.g. in the commercial poultry sector
  • Insight into Erysipelas strains in Dutch poultry
  • Animal health barometer for poultry 2021

Download Animal Health Monitoring Poultry april 2022 (PDF)

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