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Bird flu at poultry farms in 2021/2022

Published on
January 4, 2022

Wageningen Bioveterinary Research (WBVR) has confirmed yet another outbreak of bird flu in the Netherlands. Highly pathogenic H5N1 avian influenza was found in laying hens at a poultry farm in Bentelo. To prevent the virus from spreading, the Dutch Food and Consumer Product Safety Authority (NVWA) culled all 120,000 animals at the site.

Next to the infected farm is a poultry farm of the same owner with 69,000 chickens. This farm is preventively culled.

Very high risk of infections at poultry farms

The Rapid Risk Assesment (in Dutch) of November 2021 by WBVR indicates a very high risk for HPAI bird flu infections at commercial poultry farms in the Netherlands.

Housing requirement

As a result of the first outbreak in Zeewolde on 26 October, a housing obligation was set in place by the government for all commercial poultry farms in the Netherlands. Zoos, petting zoos and hobby farmers are required to fence off their poultry and waterfowl to prevent contact between these birds and diseased wild birds or their droppings.

A nationwide ban applies to exhibiting poultry and waterfowl and visits to bird accommodation where at-risk birds are kept.

Genetic analysis indicates the introduction of a new HPAI H5N1 virus by migratory birds

WBVR has analysed the HPAI H5N1 viruses found at the first three infected Dutch farms since October 2021. The virus is a newly introduced one, probably brought to the Netherlands by migratory birds. The viruses currently present in the Netherlands are not related to the Asian H5N1 strains that can infect humans.

Further reading on the H5N1 genetic analysis

WBVR has performed whole genome sequencing of the HPAI H5N1 viruses found at the first three commercial poultry farms that were infected since October 2021. This analysis has revealed a different genetic composition to the HPAI H5N1 viruses found in the Netherlands earlier in 2021, even as recently as the summer. The latest HPAI H5N1 viruses found in the Netherlands feature new PB2, PA and NP gene segments. A virus with the same genetic composition was identified in late September 2021 in Saratov, Russia. The analysis indicates that the virus is new to the Netherlands and that it was probably introduced by migratory birds.

Genetic analysis of these HPAI H5N1 viruses has revealed that they belong to H5 clade 2.3.4.4b. The viruses are therefore related to HPAI H5 viruses that have caused previous outbreaks, starting from 2016.

The H5N1 viruses currently present in the Netherlands are therefore not related to the zoonotic Asian H5N1 strains that can infect humans. There is a low risk of the new H5N1 viruses infecting humans, according to an assessment by the Institute for Public Health and the Environment (RIVM). However, people are still advised to avoid contact with any dead birds, wild or captive.

Infections from autumn 2021

Tables: Highly pathogenic avian influenza (HPAI) infections as of October 2021 at Dutch poultry farms and hobby farms with 50 or more birds.

Highly pathogenic bird flu at commercial poultry farms

Location Type of farm Number of animals Type Date
Bentelo Laying Hens 189,000 H5N1 4 Jan 2022
Blija Broilers 222,000 H5N1 3 Jan 2022
Ysselsteyn Turkeys 64,000 H5N1 21 Dec 2021
Den Ham Broilers 80,000 H5N1 17 Dec 2021
Vinkeveen Laying hens 10,000 H5N1 21 Nov 2021
Tzum Broilers 122,500 H5N1 14 Nov 2021
Lutjegast Laying hens 48,000 H5N1 8 Nov 2021
Zeewolde Meat ducks 21,000 H5N1 5 Nov 2021
Zeewolde Meat ducks 10,000 H5N1 4 Nov 2021
Grootschermer Broilers 107,000 H5N1 30 Oct 2021
Zeewolde Laying hens 36,000 H5N1 26 Oct 2021

Highly pathogenic bird flu at large hobby farms

Location Type of farm Number of animals Type Date
Nieuwerbrug Small-scale farm 220 H5N1 14 Jan 2022
Parrega Private owner 200 H5N1 3 Nov 2021
Assendelft Small-scale farm 190 H5N1 1 Nov 2021

For all cases tested positive see the bird flu map elsewhere on this page

This page was last updated on January 17th.