For the first time this fall, cases of highly pathogenic avian influenza (HPAI) have occurred on poultry farms in Bulgaria, Great Britain, and The Netherlands. Worst affected so far have been commercial birds in Hungary, where the virus has hit premises in three more regions.
The first HPAI cases of the 2024-2025 season in Bulgaria were detected during the last week of October.
The presence of the H5N1 virus variant was confirmed in a flock of close to 374,000 poultry at a farm in Yambol, according to the official notification to the World Organisation for Animal Health (WOAH). Yambol is a province in the southeast of Bulgaria.
Following an eight-month hiatus, the same virus was detected on a Dutch poultry farm last week. Directly impacted was an organic layer flock of around 23,000 birds in the central-eastern province of Gelderland.
Reacting to the news, agriculture minister Femke Marije Wiersma said that bird flu was likely to re-emerge in The Netherlands sooner or later. However, she said, the development is a heavy blow for the affected poultry farmer, and the ministry is taking appropriate measures.
Among those measure is the monitoring of nearby poultry farms. There are no such premises within a 1-km radius of the outbreak, but 13 are located within 3km.
For the first time since March of this year, poultry in Great Britain have tested positive for the H5N1 HPAI virus.
According to the official WOAH notification, affected was a small flock of poultry in Cornwall. Increased mortality and clinical signs were observed among the 49 birds last week.
Contact with infected wild birds is thought to be the most likely source of infection. Cornwall is the most southwesterly county of England.
Rise in farm outbreaks elsewhere in Europe
Based on reports to WOAH, presence of the H5N1 HPAI virus serotype has been confirmed at 155 poultry farms in nine countries of Hungary since September. Hungary is by far the country worst affected by the disease so far this season. Furthermore, the nation’s veterinary agency has recorded the first cases in three of these counties over the past week.
Most of the official reports omit details of the flock sizes at affected farms in Hungary. However, most of those affected have been ducks or geese — for fattening, foie-gras production or breeding.
So far this year, a total of 344 HPAI outbreaks linked to the H5N1 virus variant have been registered in 18 countries in and adjacent to Europe. This is according to the latest update of the Animal Disease Information System by the European Commission (EC; as of November 13). The system monitors listed animal diseases in European Union member states and surrounding states (but not Great Britain).
For comparison, 521 outbreaks in this population in 24 countries were reported to the EC system during the whole of last year.
Of the total to date in 2024, the H5N1 virus serotype has been identified as the cause in 281 of the outbreaks in 17 of the countries.
So far this year, the EC System identifies the country with the most HPAI outbreaks as Hungary (with 156). It is followed by Moldova (45), and Poland (37), while Bulgaria and Germany each have 18.
Also registering new outbreaks in commercial poultry to WOAH over the past week have been France (at three farms), Italy (two), and the Czech Republic (Czechia) and Poland, each with one additional outbreak.
HPAI outbreak total in captive birds reaches 100
The EC system monitors the disease situation in captive birds separately from commercial poultry. This category generally covers backyard poultry, zoos, and similar premises.
For the year to date, the system has registered a total of 100 outbreaks in this category in 13 countries (as of November 13).
For comparison, 15 nations confirmed a total of 93 outbreaks affecting captive birds to the EC during the whole of 2023.
Over the previous week, two further flocks of captive birds have been confirmed with HPAI in each of Slovakia and Ukraine, and one in Moldova.
Registering outbreaks in this population with WOAH over the past week have been also France, Italy, and Poland — each with one additional outbreak, and all linked to the H5N1 virus serotype.
Meanwhile, Norway has reported its first outbreak in poultry involving the H5N5 virus variant. Affected was a backyard flock of 91 birds not far from the city of Trondheim.
Outbreak total in wild birds close to 650
So far in 2024, the EC has been informed about a total of 646 outbreaks of HPAI affecting wild birds in 31 countries.
For comparison, 30 nations recorded more than 3,500 outbreaks with the system during the whole of 2023.
Over the previous week, new cases had been reported to the EC by Austria, Croatia, France, Germany, Hungary, Italy, Poland, Portugal, Romania, Slovakia, Slovenia, and Switzerland. All of these were linked to H5N1 virus serotypes.
The H5N5 virus serotype was identified in one more wild bird in Norway. Furthermore, the animal health agencies of Great Britain and Iceland reported to WOAH one additional case testing positive for the same virus variant.
View our continuing coverage of the global avian influenza situation in poultry, and on disease developments in the U.S. dairy sector.
