NEW research has confirmed this winter’s avian influenza season as the worst on record, with a total of 2,398 outbreaks across the continent and the UK and 46 million birds culled.

And with highly pathogenic H5 strains of the virus persisting in wild birds since the winter of 2020-2021, it may be endemic in wild birds in parts of Europe, according to the latest review by the European Food Safety Authority (Efsa).

See also: Govt lab fighting avian influenza needs rebuilding

That would imply a year-round risk to poultry production and wildlife, as well as a smaller risk to human health, with a peak during the Autumn and winter months.

The comments were made in Efsa’s most recent analysis of AI, covering 16 March – 10 June this year.

Over that period, there were 1,182 HPAI virus detections across the 28 EU/EEA states and the UK – 750 in poultry, 410 in wild birds and 22 in captive birds. Of the outbreaks in poultry, 86% were considered secondary due to spread between farms.

Secondary spread

France accounted for 68% of the outbreaks, Hungary for 24% and the remaining countries less than 2% each.

A secondary peak of detections in wild birds has been reported and continued beyond the reporting period – 10 June.

Mass die-offs of wild birds have been recorded in Scotland, as we have previously reported, and in the Netherlands, Iceland, Norway, France and Greece.

There is also a change from migratory wild waterfowl being infected to more raptors and other wild bird species.

This, the report says, “suggests a shift of infection from winter migrants to wild birds that are resident and/or breeding in Europe, including those that breed in colonies”.

Efsa says that, in the short-term, measures to control AI should include “appropriate biosecurity measures” and surveillance strategies, and in the medium to long-term, countries could consider reducing the density of poultry in high-risk areas.

Read the full publication on Efsa’s website.