Avian Influenza: Could the current situation represent a Public Health problem?blem?

Abstract

Introduction: Avian influenza is a viral disease caused by influenza A viruses that primarily affects birds and, occasionally, mammals and humans. It is classified as low or high pathogenicity according to its severity in birds and is mainly transmitted through direct contact with infected animals, with potential zoonotic and pandemic risk. The objective was to describe the epidemiology (animals and humans), the situation global and in Spain, and future challenges are analyzed from a One Health perspective.

Method: Bibliographic review of the current global situation based on scientific evidence and recent documents.

Results/Discussion: Highly pathogenic avian influenza (HPAI) A(H5N1), particularly clade 2.3.4.4b, has spread globally since 2020, with increasing outbreaks in domestic and wild birds and growing involvement of mammals. Europe has recorded unprecedented numbers at the begining of 25-26 season, and in Spain active circulation and outbreaks in domestic birds have required preventive measures. Since 1997, approximately 1,000 human cases have been reported, generally linked to close contact with infected animals and without sustained human-to-human transmission. The risk to the general population is very low, and control measures focus on surveillance, animal control, and protection of exposed workers.

Conclusions: At the beginning of the 2025–2026 season, Europe is experiencing unprecedented notifications of outbreaks in wildbirds. Although the human risk in Spain remains low, the virus’s ability to mutate and break through species barriers, requires continuous surveillance, strengthened biosecurity and international cooperation under a One Health approach.