For the coming winter, Europe is facing a higher risk of highly pathogenic avian influenza (HPAI) in birds than in previous years.
This is the main conclusion of a new assessment of the avian influenza situation across the continent from the European Food Safety Authority (EFSA). The report was prepared with the European Centre for Disease Prevention & Control, and the EU reference laboratory.
Already in early July, EFSA had described 2021-2022 as Europe’s worst ever avian flu season. However, the situation has not improved since. Between June and September, there was an unprecedented number of HPAI cases in wild and domestic birds in many European countries, according to the latest report. In previous years, cases in both populations have dwindled.
Summarizing the recent pattern of disease, the report puts the number of detections at 788 between June 11 and September 9. This total comprised 56 detections in poultry, 22 in captive birds, and 710 in wild birds. Furthermore, there was wide distribution of the cases across 16 countries of the European Union (EU), European Economic Area (EEA), and the United Kingdom (U.K.).
As a result of the persistence of the virus in Europe during the summer, and the imminent arrival of migrating wild birds, EFSA is warning of a higher risk of HPAI infection than in previous years.
This has led the authority to urge that appropriate HPAI mitigation strategies are implemented with urgency. Among these, it recommends effective biosecurity measures be put in place, along with surveillance strategies for early virus detection. EFSA is also calling for national administrations to consider medium and long-term prevention strategies for the highest-risk areas. These include areas of high poultry population density, and the most susceptible avian species and production systems.
At the end of September, the agriculture ministry of France raised the avian flu alert level, and reinstated disease control measures that had been eased during the summer months.
The Netherlands takes steps to control HPAI
Over the past two weeks, the Dutch agriculture ministry has confirmed 11 new outbreaks of HPAI linked to the H5N1 virus serotype in the nation’s poultry flocks. They occurred at premises in five of the country’s northern and eastern provinces — Drenthe, Friesland, Gelderland, Groningen, and Overijssel. Affected have been three small flocks of ornamental water birds, and 11 farms with broilers, laying hens and/or ducks. Including one epidemiologically linked farm, more than 410,000 poultry have been culled since September 21.
Last week, one of the first announcements made by new agriculture minister Piet Adema was the mandatory protection of the nation’s most at-risk birds. The decision followed a risk assessment by an expert group, and the earlier introduction of confinement and screening of poultry in limited areas.
Now, all commercial birds must be kept housed and subjected to regular testing. Only exceptions are pheasants, waterfowl, and ratites (ostriches), which need not be confined but must now be monitored. Meanwhile, non-commercial birds such as those at zoos and in hobby flocks must be shielded so they have no contact with wild birds or their droppings.
Dutch study begins into vaccine efficacy
At the end of September, Wageningen Bioveterinary Research (WBVR) announced it was testing several vaccines against HPAI. Part of Wageningen University & Research, WBVR was commissioned to carry out the experiments by the Dutch agriculture ministry.
Currently under investigation are vaccines from three commercial companies against virus of the H5 family in laying hens, compared with experimental products developed using new technologies.
According to avian flu researcher Nancy Beerens, the trial period will last three months, and these vaccines will be compared for efficacy clinical signs and virus transmission. This latter point is particularly important, according to Beerens, because a vaccines that does not reduce virus transmission sufficiently could lead to the “silent spread” of the infection to more farms.
“This aspect is one of the reasons why the European Union has rules in place for vaccinated poultry,” she said.
Combined with those of similar trials carried out elsewhere in Europe, she added, the results from Wageningen might pave the way for vaccination of poultry as part of future European agricultural policy.
England’s housing order extended
Following a continued spike in new HPAI outbreaks, an order was introduced to keep poultry and captive birds housed specified areas of eastern England. This was announced by the agriculture department, Defra on October 8.
As an extension to the Avian Influenza Prevention Zone (AIPZ) measures introduced in this area last month, affected owners are urged to make preparations for the more stringent measures in the coming days.
From October 12, it will be mandatory for all bird owners in the counties of Norfolk, Suffolk, and parts of Essex to keep poultry and captive birds confined in houses. Furthermore, stricter biosecurity procedures must be followed.
Under the previous AIPZ, there were requirements to restrict access to farms for non-essential visitors, disinfect vehicles regularly, and ensure workers changed clothing and footwear before entering bird enclosures.
In addition from this week in the high-risk area, all poultry and captive birds will have to be housed or kept in netted enclosures, with minimum direct or indirect access to wild birds, and none to ponds and watercourses. Before and after contact with birds, clothing, footwear, equipment and vehicles must be cleaned and disinfected. Poultry houses must be cleaned and disinfected continuously, vermin controlled, and disinfectant points must be kept effective at all entry and exit points. Last but not least, records must be kept of mortalities, movements of poultry and products, and any changed in production.
According to the Animal and Plant Health Agency, which is part of Defra, there have been 152 confirmed outbreaks of HPAI in England since October of 2021, and 18 since the start of this month (as of October 9).
Of the latest outbreaks, 13 were in commercial poultry flocks or captive birds in the newly restricted parts of eastern England. Other cases were detected at two locations in Staffordshire (central England), and one each in Oxfordshire (south-east), Somerset (south-west), and Lancashire (north-west).
Overall situation in European poultry flocks
As of October 1, 1,852 HPAI outbreaks have been recorded across Europe so far this year. This is based on the latest update of the Animal Disease Information System by the European Commission (EC). The total represents an increase of eight outbreaks since September 25. To date, one or more outbreaks have occurred in 21 European countries since the start of 2022.
For comparison, this season’s figure has passed the total of 1,756 outbreaks registered with the EC by 24 European states over the whole of 2021.
This year, France has been the nation reporting the most outbreaks to the EC (1,365). Next came Hungary (205), the Netherlands (58), Germany (55), and Poland and Spain (each with 36).
The latest official reports submitted by the U.K. authorities to the World Organisation for Animal Health (WOAH) covered 10 outbreaks, all linked to the H5N1 virus serotype.
Starting in the period September 8-25, three were in backyards, and seven on commercial premises. Among the larger flocks to be affected were 61,000 meat turkeys, almost 32,000 laying hens, around 24,500 geese, and 17,000 broilers.
These recently reported outbreaks bring the total recorded among U.K. commercial poultry since October of 2021, directly impacting 3.25 million birds through mortality or culling. In addition, more than 4,000 non-commercial/backyard birds have also been affected by the infection.
Over the past week, Belgium’s veterinary authority has notified WOAH about one new HPAI outbreak in a flock of around 113,000 chickens in West Flanders.
In Portugal, cases were detected in almost 12,000 meat turkeys at a farm near the capital, Lisbon.
Further outbreaks among backyard flocks, captive birds
In its reporting system, the EC has recently introduced a separate category for HPAI outbreaks in captive birds. Covering non-commercial poultry flocks, zoos, and similar premises, this year’s total stands at 131 (as of October 1).
With 54 so far this year, France leads the region’s nations for this type of outbreak, followed by the Netherlands (37). Each of the 13 other countries reporting cases in this category in 2022 has registered between one and eight outbreaks.
Since September 25, France has confirmed with the EC seven new outbreak in backyard/captive birds, and the Netherlands three more.
In Germany, North Rhine-Westphalia is the latest state to notify WOAH about new cases in a non-commercial poultry. First outbreak in this state since May of this year was in a backyard flock comprising 240 birds.
Meanwhile, the latest outbreak in Belgium reported to the same agency affected a backyard flock of 18 birds, and 1,556 of mixed species at the premises of a bird trader.
HPAI outbreaks continue in wild species across Europe
For the year to October 1, a total of 2,701 HPAI outbreaks in wild birds have been reported to the EC. One or more outbreaks have now been confirmed in 32 European states in 2022.
Of the total, 1,134 outbreaks have been reported by Germany, followed by the Netherlands (552) and France (239). Since September 25, total cases have also risen for Belgium, Finland, Ireland, Italy, Norway, and Spain.
For comparison, the EC disease system recorded a total of 2,437 HPAI outbreaks in captive and wild birds in 31 European states during the whole of 2021.
A red fox has tested positive for the H5N1 HPAI virus in the Republic of Ireland - a first cases in an unusual species in County Cork.
Not covered by the EC system (except for Northern Ireland), the U.K. has registered a further 52 cases of HPAI in wild birds with WOAH.
For all of the outbreaks described above, tests were positive for the H5N1 serotype of the HPAI virus.
View our continuing coverage of the global avian influenza situation.
