New measures include preventative culling of poultry from farms near to a confirmed outbreak in a high-risk area. Meanwhile, France continues its suffer steadily mounting losses from further outbreaks in commercial birds, and 16 countries report the detection of HPAI virus in wild birds.
For the Netherlands, the first cases of highly pathogenic avian influenza HPAI for the winter season were detected at the end of October last year. Up to March, just over 30 outbreaks were confirmed in the nation’s poultry flocks — as well as in wild birds — in a similar pattern to other European nations.
However, in the period April 12-21, the Dutch agriculture ministry has already reported six further outbreaks — each on a commercial premises. All have occurred within the eastern province of Gelderland. In each case, presence of an H5 virus serotype — likely H5N1 — has been confirmed, and high pathogenicity is suspected.
Because of the spike in infections and the concentration of poultry production in this region, the ministry has stepped up disease control measures over the past week.
Currently, all poultry farms within 1 kilometer of a confirmed outbreak are being depopulated, and the birds are undergoing preventative culling. At premises within a 3-km radius, monitoring and testing are being intensified so surveillance continues for 14 days. For all units within 10 kilometer of the outbreak, the transport ban on poultry and their products continues as before.
These measures have been in place since mid-April, when the first of five recent outbreaks was confirmed by the ministry. Affected was a laying hen flock near Barneveld, where around 34,000 birds were culled. Subsequently, 26,000 chickens were destroyed near Voorthuizen, and near Lunteren, 280,000 chickens at two farms and 3,000 ducks at another premises have been culled.
Within 1 kilometer of these five outbreaks were 19 poultry farms that are affected by the preventative cull. This covers more than 145,000 birds around the Lunteren outbreak alone. Birds at a hatchery in the same area have been spared.
Based on these latest ministry reports and previous official notifications, Dutch poultry losses from HPAI outbreaks since October already exceed 2.25 million birds.
France registers more than 1,300 outbreaks in poultry
Eight of the 13 regions of mainland France have reported at least one HPAI outbreak since the start of the 2021-2022 winter.
Latest update from the French agriculture ministry puts the number of confirmed HPAI outbreaks on commercial farms since November of last year at 1,315. This is as of April 20, and the figure is 85 more than on April 8.
Accounting for most of the latest outbreaks — 24 — is Dordogne in the southwestern region of Nouvelle-Aquitaine. Recording first outbreaks of the season are Haute-Vienne in the same region, and Aveyron in Occitanie in the south of France.
Registering the most new infections over the past two-week period were departments in regions of Nouvelle-Aquitaine, Occitanie, and Pays de la Loire. Part of this latter region in western France is Vendée, which continues to be the department worst affected by HPAI on commercial premises this season. There have been 529 confirmed outbreaks there.
In France, ministry releases do not include details of numbers of poultry involved in each outbreak. However, official reports to the World Organisation for Animal Health (OIE) up to the end of March put the number of mortalities at more than 327,000, with just under 12 million domestic poultry culled.
According to the ministry, 28 backyard poultry flocks have also tested positive for HPAI since the end of last year. These have occurred in 15 departments, including most recently for the first time Sarthe in Pays de la Loire.
General HPAI situation in European poultry flocks
As of April 8, 18 European countries had registered one or more outbreaks in poultry so far this year. This is according to the latest update of the Animal Disease Information System by the European Commission (EC). Up to that date, the System has a total of 1,300 outbreaks for the year.
For comparison, 1,756 outbreaks in poultry were registered with the EC by 24 European states during the whole of 2021.
Of the 88 new outbreaks recorded since the previous update on April 1, 86 were in France. With 1,098 outbreaks, France accounts for 84% of the region’s total for the year to date. With an unchanged total of 31 outbreaks, Spain has registered the next highest total for the year so far.
Also registering new outbreaks though the EC system were Germany and Italy.
Further outbreaks in central European poultry
Over the past week, veterinary authorities of Bulgaria and Hungary have each notified OIE about two new outbreaks in poultry flocks.
In Hungary, latest outbreaks are linked to the H5N1 HPAI virus, and follow short periods free of the disease in two southern counties. Affected since mid-April have been a farm with around 3,500 foie-gras geese in Bacs-Kiskun, and another in Bekes with an unreported number and type of poultry.
Meanwhile, the virus responsible for HPAI outbreaks in Bulgaria has not been typed. Over the past week, however, the national animal health agency has registered two new outbreaks in poultry to the OIE. These involved firstly a backyard flock in the southeastern province of Burgas, One week later, the disease hit a large commercial layer farm with almost 88,000 hens in the central province of Plovdiv.
A flock of more than 44,500 meat turkeys in North Rhine-Westphalia is the latest German poultry flock to test positive for the H5N1 HPAI virus. This is according to the latest official OIE notification. Furthermore, data published by the national veterinary reference laboratory, Friedrich-Loeffler Institute point to a second outbreak in turkeys in the same area.
In the southwest of the Czech Republic, a backyard poultry flock tested positive for the same virus serotype in mid-April. Based on OIE notifications, this was the first outbreak in the country since the beginning of March.
To the OIE, the veterinary authority of Croatia has recently declared an earlier HPAI situation “resolved.” This followed a single outbreak in a backyard flock in mid-January.
HPAI in European wild birds
For the year to date, HPAI outbreaks in wild birds across Europe reported to the EC animal disease system have reached 1,578 (as of April 8). This represents an increase of 49 compared with the previous update one week previously. Of these, 15 were reported by the Netherlands, and 13 by Germany. With the first case of this year in Northern Ireland, 30 states have already registered one or more outbreaks in wild birds through the system so far in 2022.
These figures compare with 31 European countries registering a total of 2,437 HPAI outbreaks in wild birds with the EC last year.
In 2022 so far, Germany has detected the most outbreaks in wild species (804), followed by the Netherlands (323), and Denmark (82). Also confirming with the EC new outbreaks were Austria, France, Greece, Hungary, Lithuania, Norway, Spain, and Sweden.
In addition, one or more new cases have been detected in Belgium, Bulgaria, Finland, Iceland, and Poland. This is according to recent official notifications to the OIE. For Bulgaria and Iceland, the isolated cases have been reported as “resolved.”
All of the outbreaks reported above have involved the H5N1 virus serotype.
In contrast, the Danish authorities have reported that a harbor seal was found to be infected with the H5N8 virus variant in 2021. In a case in an “unusual host,” one dead seal out of 44 tested in September was positive for this virus serotype.