Experts discover cause of bird flu outbreak across Europe

Europe is grappling with an unprecedented and early surge in bird flu, driven by widespread outbreaks in wild birds, the European Food Safety Authority (EFSA) announced on Thursday.

This highly pathogenic avian influenza has already necessitated the culling of hundreds of millions of farmed birds, disrupting food supplies and driving up prices, though human infections remain rare.

While outbreaks typically peak in autumn with migratory patterns, this season has witnessed an earlier onset, causing significant mortality among wild bird populations.

Common cranes along routes spanning Germany, France, and Spain have been particularly affected, alongside numerous waterfowl.

Between 6 September and 28 November, the EFSA’s report detailed 2,896 detections of the highly pathogenic H5 avian influenza virus – predominantly H5N1 – across 29 European nations.

Of these, 442 cases were identified in poultry, with a substantial 2,454 found in wild birds.

"We are currently seeing an unprecedented sharp increase in the highly pathogenic avian influenza virus detections, mostly in wild birds," Lisa Kohnle, scientific officer at EFSA, told Reuters.

Poultry outbreak numbers were similar to previous years but five times higher than in 2023, and almost double those of 2021. Turkeys were the most affected.

"What is interesting for poultry is that in previous years those epidemics were characterised by a lot of farm-to-farm spread," Kohnle said. "This year it seems we mostly have introduction from wild birds".

For humans, bird flu infected 19 people in four countries (Cambodia, China, Mexico and the US), killing one in Cambodia and one in the US, EFSA said. All cases involved exposure to poultry or poultry environments.

Bird flu outbreaks in mammals were fewer than in 2022 and 2023, but remain a concern due to potential mutations that would make it transmissible between humans.

Kohnle said detections were likely to keep rising, although high wild bird mortality could prompt tighter farm controls and help slow the virus's spread.