The Director of the Barcelona Public Health Agency, Joan Ramón Villalbí, has expressed concern over a potential mutation of the avian influenza virus. According to Villalbí, this mutation could lead to a form of flu in humans that is "much more lethal" than common infections, reaching levels comparable to the 1918 Spanish flu.

Speaking on the program Bon dia, Barcelona, Villalbí stated that mechanisms are in place for the early detection of such a mutation. He also highlighted the ongoing surveillance efforts aimed at preventing the spread of avian flu cases.

Avian influenza is a viral disease primarily affecting birds, both domestic and wild. Caused by subtypes of the influenza A virus, it can range from mild illness to being extremely contagious and fatal. Most outbreaks occur in rural or peripheral areas with poultry farms. In 2025, according to data from the Generalitat government, six outbreaks were recorded in Catalonia.

While human transmission is uncommon, it is possible through close contact with infected animals or contaminated surfaces. Symptoms include high fever, dry cough, headache, muscle pain, and general malaise, similar to the common flu. The incubation period typically lasts two to eight days, and treatments like oseltamivir and zanamivir are available to reduce the severity and duration of the illness.