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The ECDC publishes a highly detailed avian influenza surveillance report roughly every 3 months, and while they tend to be EU centric, in its 70+ pages you'll find ample coverage of outbreaks and infections from around the world on a wide variety of avian subtypes.
Four years ago, following a complex series of genetic changes to the HPAI H5 virus, we began to see a global surge and spread of H5N1, characterized by increased spillovers into mammals (mink, foxes, marine mammals, and eventually even cattle).
Avian influenza overview December 2024-March 2025
Surveillance and monitoring
21 Mar 2025
Publication series: Avian influenza overviewBetween 7 December 2024 and 7 March 2025, 743 highly pathogenic avian influenza (HPAI) A(H5) virus detections were reported in domestic (239) and wild (504) birds across 31 countries in Europe. HPAI A(H5N1) virus detections were predominant and mainly located in central, western and south-eastern Europe.Most HPAI A(H5) virus detections in wild birds concerned waterfowl, particularly mute swans, barnacle geese and greylag geese. Limited secondary spread was observed among the poultry outbreaks, and outdoor poultry access remained an important risk factor at the interface between wild and domestic birds. HPAI A(H5N5) outbreaks occurred only in wild birds and were increasingly reported in waterfowl. For the first time since spring 2024, several HPAI virus detections were reported in domestic cats and wild carnivores in Europe.
No evidence of human-to-human transmission has been documented during the reporting period. The risk of infection with the avian A(H5) influenza viruses of clade 2.3.4.4b currently circulating in Europe remains low for the general public in the European Union/European Economic Area (EU/EEA). The risk of infection remains low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.In the United States of America (USA), the number of dairy cattle farms reportedly affected rose to almost 1,000 in 17 States, and a different HPAI A(H5N1) virus genotype (D1.1) was reported in this species.Between 12 December 2024 and 7 March 2025, 22 new cases of avian influenza virus infection in humans were reported in the USA (12 A(H5) cases), Cambodia (two A(H5N1) cases), United Kingdom (one A(H5N1) case), and China (six A(H9N2) cases and one A(H10N3) case).Most of the A(H5) human cases (93%, n = 14/15) had reported exposure to poultry or dairy cattle prior to avian influenza virus detection or onset of illness. Considering the widespread circulation of avian influenza viruses in animal populations, human infections with avian influenza viruses remain infrequent. No evidence of human-to-human transmission has been documented during the reporting period. The risk of infection with the avian A(H5) influenza viruses of clade 2.3.4.4b currently circulating in Europe remains low for the general public in the European Union/European Economic Area (EU/EEA). The risk of infection remains low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.
Avian influenza overview December 2024–March 2025 - EN - [PDF-2.43 MB]
As impressive as these quarterly reviews are, they can only provide us with an overview. Surveillance and reporting has it's limits - even in higher resource European nations - and this report reflects only what countries were willing or able to publicly divulge.
Last summer the ECDC published Enhanced Influenza Surveillance to Detect Avian Influenza Virus Infections in the EU/EEA During the Inter-Seasonal Period which cautioned:
Sentinel surveillance systems are important for the monitoring of respiratory viruses in the EU/EEA, but these systems are not designed and are not sufficiently sensitive to identify a newly emerging virus such as avian influenza in the general population early enough for the purpose of implementing control measures in a timely way.
Similarly, in 2023's analysis from the UKHSA (see TTD (Time to Detect): Revisited), the UK estimated there could be dozens or even hundreds of undetected human H5N1 infections before public health surveillance would likely detect them, potentially over a period of weeks or even months.
For reasons that likely vary widely between nations, details that once were shared are now often redacted or delayed (see From Here To Impunity).
While the risk assessments provided in this overview (low or very low for the general public) seem reasonable based on the data provided, confidence in the quality and completeness of that data is difficult to gauge.
Which is why - despite recent slowdowns in reported cases - we can't afford to be complacent.
