Health authorities in Extremadura and Andalusia are raising the alarm: the West Nile virus is spreading in Spain. After the first case of 2025 was confirmed in Extremadura in a 57-year-old man, officials are calling for increased vigilance. While Extremadura relies on classic prevention measures, Andalusia is taking an innovative approach by using a natural ally in the fight against mosquitoes – the bat. This strategy, which highlights the ecological role of bats, could make a decisive difference.
First West Nile Case in Extremadura: Asymptomatic Infection Confirmed
The Extremadura Health Service (SES) reported the first confirmed case of West Nile fever. A 57-year-old man from the Cáceres health region tested positive for the virus during routine donor screenings. Fortunately, the infection was asymptomatic, a scenario that occurs in about 80% of human infections. Nevertheless, an alert has been issued in all health areas to strengthen diagnostic capacities and raise public awareness.
Andalusia’s Natural Weapon: The Bat
In Andalusia, authorities are implementing a unique and ecologically sustainable strategy. In the Sierra de Aracena and Picos de Aroche Natural Park, home to at least nine different species of bats, these insectivorous mammals are being used as biological pest controllers. A single bat can consume its own body weight in mosquitoes each night, about 500 specimens.
In collaboration with the energy company Endesa, the Junta de Andalucía has launched a pilot project to create bat shelters near electrical infrastructure and build nesting boxes. A five-year monitoring program will assess the success of this initiative. Night routes are also being organized for the public to raise awareness of the important ecological role of bats as “free and efficient biological controllers” in the fight against diseases like West Nile fever.
