Avian Influenza Update – September 2025

Published on : 12 Sep 2025

Since the last update, the avian influenza (AI) situation across Great Britain has remained relatively stable, with no new declarations of disease control zones and activity focused mainly on ongoing surveillance. This is encouraging news, as it indicates limited immediate pressure on the sector. While no outstanding report cases are currently under review, detections in wild birds continue, highlighting the importance of sustained vigilance and robust biosecurity measures.

Current risk levels and outbreak assessments
The risk of HPAI H5 in wild birds in Great Britain is assessed as high (event occurs very often).

The risk of poultry exposure to HPAI H5 in Great Britain is assessed as:

medium (event occurs regularly) where there is suboptimal or poor biosecurity
low (event is rare but does occur) where stringent biosecurity is consistently applied at all times.

Regional authorities (Scotland and Wales) are preparing targeted biosecurity guidance for the gamebird sector.

The UK has had 81 cases since 1st October 2024 (3 in Wales, 3 in Scotland, 4 in Northern Ireland & 71 cases in England).

Wild Birds
Since the last Avian Core Group update:

• Wild bird detections continue, with fluctuating but sometimes high positivity rates.
• 28 wild birds tested positive for HPAI H5N1 and 1 for HPAIV H5Nx, out of 374 tested.
• Cumulative total for GB since 01/10/24:
• 894 wild birds confirmed with HPAIV.
• Breakdown: 812 (H5N1), 41 (H5Nx), 41 (H5N5).
• Detected across 346 locations, involving 55 species in 90 counties.