The Netherlands Ministry of Agriculture has reported to the World Organization for Animal Health (OIE) two outbreak of H5N1 highly pathogenic avian influenza during the last week in October. The first case was diagnosed on a farm of laying hens near the town of Zeewolde in the Province of Flevoland in Central Holland. A total of 36,000 hens were housed on the farm that is being depopulated. Given that the farm was designated as an organic unit it is presumed that flocks had outside access and were vulnerable to infection from migratory waterfowl. Appropriate restrictions have been place on movement of birds within a six-mile area around the index farm and intensive surveillance is in progress involving six other farms within 1.9 miles and nine other farms within six miles of the affected premises.
The most recent outbreak occurred on a farm housing 107,000 broilers in three adjacent buildings. In addition to depleting the farm in the Municipality of Alkmaar, and imposing the quarantine restrictions as required by the OIE, preemptive depletion of a flock of 18,700 broilers was carried out based on proximity to the larger farm and presumably some biological connection.
The Minister of Agriculture Carola Schouten has mandated confinement of all poultry flocks to limit transmission of influenza virus from migratory waterfowl. Residents of the Netherlands have been requested to report dead wild birds to agricultural and veterinary authorities to be sampled for the presence of influenza virus.
Other nations in Europe are experiencing cases of avian influenza. On October 22nd, authorities in Germany reported on an outbreak involving 633 geese on a farm in Brunsbuttel in the northern state of Schleswig-Holstein. Isolates of H5N1 were obtained concurrently from free-living birds in the states of Bavaria and West Pomerania. A second outbreak in Germany involved a small multi-species poultry farm with 224 chickens, geese and ducks in the state of Brandenburg
A farm holding 27,600 turkeys in Sjaeland, Denmark was diagnosed with H5 avian influenza on October 30th followed by depletion and quarantines.
Russia reported an outbreak of H5N1involving 422,000 “birds” (type not specified) on a farm near Kirov The widespread distribution of cases suggests extensive infection among waterfowl with implication for non-confined poultry flocks in Western Europe.
England recorded mortality in swans on the River Avon at Stratford and in waterfowl at the Wychbold Rehabilitation Center, also located in Worcestershire. A separate outbreak in a small farm was diagnosed in Wrexham, Wales concurrently with isolation from dead wild birds.
The following extract from a September 29th E.U. report on avian Influenza is provided to illustrate the magnitude of the problem of interaction between migratory waterfowl serving as reservoirs and disseminators of virus and both backyard and commercial flocks in Europe:-
The occurrence of HPAI A(H5) virus incursions in commercial farms
even where birds are kept indoors raises concern about the capacity of
applied biosecurity measures in effectively preventing virus exposure.
Biosecurity standards should be revised and reinforced, and their
implementation regularly checked, primarily in poultry production
systems at high risk of avian influenza.
"The 2020-2021 epidemic with a total of 1,298 outbreaks in poultry,
22,9 million birds affected, 85 detections in captive birds, and 2,394
events in wild birds in 31 European countries appears to be one of the
largest HPAI epidemics that has ever occurred in Europe. Note that the
number of reported wild bird events is an underestimate of the total
number of wild birds that have died from HPAI during this epidemic."