Close to 48 million poultry have been culled in response to Europe’s largest highly pathogenic avian influenza (HPAI) epidemic. As the region’s winter deepens, the number is expected to rise further still.
Over the 2021-2022 epidemic seasons, 2,467 outbreaks were recorded on poultry farms, while 187 detections were seen in captive birds and 3,573 in wild birds, according to data published by the European Food Safety Authority (EFSA) in late September.
Indicative of the severity of Europe’s most serious epizootic in recent history, conclusions on a strategic approach for the developing vaccination as a complementary tool for HPAI control and prevention were adopted by the European Union Council in May.
In some parts of the continent, the disease is thought to be putting the survival of poultry production at serious risk.
In France, for example, the Pays de Loire, the country’s second largest poultry-producing region, recorded 860 outbreaks of HPAI in only six months. ANVOL, the country’s broiler association, has warned that the entire production chain is in danger and that, for the first time, all domestic species had been affected.
Unprecedented spread
Europe’s 2021-2022 HPAI season has had unprecedented geographical spread, extending from the Svalbard Islands, one the world’s northernmost inhabited areas, through to the south of Portugal. Thirty-seven European countries have been affected.
While the European poultry industry may now again be heading into the peak transmission period, it has had at least some relief over recent months.
EFSA’s latest report, covering June-September, reveals that the number of outbreaks in domestic poultry rapidly fell over the period, following two peaks between the fall of 2021 and the spring of 2022.
In August, however, a third, smaller, peak occurred. This comprised 56 poultry premises – five times more than during the same period during the last epidemic – with Germany, where 15 premises were affected, the Netherlands and the U.K. being the most affected countries.
In the U.K., which confirmed at least 190 bird flu outbreaks and saw over 3.5 million birds culled over the 12 months to October this year, the country’s Chief Veterinary Officer Dr. Christine Middlemiss, commented: "We are seeing a growing number of bird flu cases on commercial farms and in backyard birds across the country driven by higher levels of disease within wild birds.
"Unfortunately, we expect the number of cases to continue to rise over the coming months as migratory birds return to the U.K., bringing with them further risk of disease that can spread to our kept flocks."
Seabird colonies
Along Europe’s northwestern coast, several colony breeding seabird species have exhibited widespread and massive mortality due to HPAI, with the number of HPAI detections in seabirds being 35% higher than over the same period last year.
Summer months have traditionally seen little, or no, virus detected in seabirds. However, between June and September this year, detections in wild birds reached 710, although the actual level of infection will probably be much higher.
The highest number of detections in wild birds occurred in Germany, with 199 incidences reported. Germany was followed by France, with 142 detections, and the Netherlands and the U.K. with 112 apiece.
Changing migration patterns are thought to be contributing to the spread of the virus and its survival through the summer months, possibly due to mutation, which represents an ongoing risk for poultry production.
Since October 2020, the H5Nx 2.3.4.4b lineage of HPAI has spread across Europe, the Middle East, Africa and Asia. Seven genotypes are now present in Europe, with three having been identified for the first time during the latest reporting period.
Growing interest in vaccination
If further evidence were needed that attitudes to HPAI vaccination are changing in Europe, in late October, the International Alliance for Biological Standardization, an independent, non-profit scientific alliance, held an international meeting to look at HPAI vaccination strategies and the removal of unnecessary barriers to their usage.
The event took place at the headquarters of the World Organization for Animal Health and looked at how a harmonized vaccination strategy with updated vaccination strains and innovative technologies, combined with appropriate diagnostics, surveillance and disease management, could offer a better approach than stamping out alone.
Western European poultry hard hit by avian flu
