Developments in highly pathogenic avian influenza (HPAI) outbreaks since the autumn point to a growing risk of infections in poultry flocks, according to the latest disease risk assessment for Europe.
This is the warning to the continent’s poultry sector in the latest quarterly assessment of avian flu by the European Food Safety Authority (EFSA).
In its report, EFSA highlights that this increase in cases has begun later in 2023 than in previous years — likely as a result of the delayed migration of wild birds.
According to this source, HPAI virus was detected in 88 outbreaks in poultry and 175 wild birds in Europe over the three months to December 1. Cases were widespread, occurring in 23 European states.
EFSA noted that 11 different virus variants were identified over the period. Of these, seven were newly emerging, and affected different bird species from previous seasons — particularly cranes. Around 86% of outbreaks in wild populations involved influenza A(H5N1) viruses. Development of the new variants is likely through genetic reassortment of the circulating viruses, including low-pathogenic types thought to be present widely in wild water birds.
In poultry, all outbreaks were linked to viruses of the influenza A(H5) family. The most outbreaks were recorded in Hungary (43), but almost half of the 2.5 million poultry that died or were culled over the study period were in Bulgaria.
Most of outbreaks in poultry were traced to infections from wild birds, EFSA noted. However, there have been two clusters of outbreaks in commercial poultry in Hungary, which may have involved secondary spread.
Despite these trends, the risk to human health from these viruses remains low for the general public, reports EFSA. For those exposed to infected birds or mammals, the risk level is unchanged at low to moderate.
European poultry outbreak total reaches 485
So far this year, 473 outbreaks of HPAI have been confirmed on poultry farms in 23 European states. This is according to the Animal Disease Information System from the European Commission (EC) in its update dated December 8. Through the System, the EC monitors the disease situation in European Union (EU) member states and neighboring countries. The total includes two outbreaks in Turkey (Tűrkiye) and one in the French overseas territory of Reunion, although these territories are not on the continent of Europe.
During the whole of 2022, a total of 2,321 outbreaks in commercial poultry flocks were registered through the System by 24 countries.
Since the EC’s previous update (dated December 2), four nations together confirmed to the EC 12 further outbreaks in this category. Reporting the most new infections were France (four), Germany and Hungary (three each) and Poland (two).
For 2023 to date, the nation with the highest total — 157 - continues to be France, followed by Hungary (136), and Poland (64).
To December 8, 15 European countries have together registered a total of 97 outbreaks of HPAI in captive birds in 2023 through the EC’s system. This category covers non-commercial poultry flocks, and birds other than poultry, such as zoos. Only change from the previous edition dated December 2 was a second outbreak of the year in Slovakia.
Latest developments in HPAI in European poultry flocks
In Germany, latest update on the HPAI risk to poultry by the national veterinary reference laboratory Friedrich-Loeffler Institute is now “high.” This classification arises from the growing prevalence of avian influenza viruses in wild birds in Germany and widely across Europe. As the virus can easily be transmitted from wild species to poultry, farmers and other owners are now required by law to maintain specified biosecurity measures, and to report any signs of illness or elevated mortality in their birds.
One week previously, the French government also raised the HPAI risk level for poultry to “high.”
Latest update on the HPAI vaccination policy in France puts the number of ducks that have received their first dose of HPAI vaccine at just under 8.85 million. That was the status on December 8, according to the agriculture ministry. The scheme mandates the vaccination of ducks on commercial premises in regions of high production density in the west and south west of the country — Pays de la Loire, Nouvelle Aquitaine, Occitan, and Bretagne (Brittany). All but one of France’s mainland regions has now begun vaccinations of this population.
HPAI spreads to eighth Hungarian county
Further details of the outbreaks are provided in the official notifications by national veterinary agencies to the World Organisation for Animal Health (WOAH).
Over the past week, the Hungarian authority has registered HPAI outbreaks at six more commercial premises. These were located in five different counties, including for the first time this season in Komarom-Esztergom in the north of the country. These outbreaks bring to 59 the total on Hungarian poultry farms over the past month, based on WOAH reports.
In Germany, first cases of HPAI linked to the H5N1 virus serotype have been detected in the western state of North Rhine-Westphalia following an eight-month hiatus. Testing positive for the virus since December 11 have been one commercial flock each of meat turkeys and ducks.
The chief veterinary office of Poland has confirmed that two HPAI outbreaks earlier this month involved a total of more than 104,000 meat turkeys in the same area in the northwestern province of West Pomerania.
Also testing positive for the same virus variant have been one commercial flock in each of Belgium and Denmark, based on recent notifications from the respective national authorities to WOAH.
More cases in wild birds across Europe
As of December 8, a total of 3,468 HPAI outbreaks in their respective wild bird populations have been confirmed to the EC by 28 states of the EU member and adjacent states, according to the EC. This is an increase of 16 from the edition dated December 2.
For comparison, 3,245 outbreaks were confirmed in 33 of the region’s nations during 2022.
Based on the EC System, Germany has registered the most outbreaks in this population so far this year — 1,096 for the year to date — followed by France (407).
Countries reporting to the EC further cases in wild birds since the previous edition were Denmark, Germany, Italy, and The Netherlands.
Also reporting new cases in their respective wild populations to WOAH over the past week were the health agencies of Austria, Belgium, and Sweden.
View our continuing coverage of the global avian influenza situation.
