The Junta de Andalucía has deployed a surveillance system against the West Nile Virus, utilizing a network of 215 traps distributed throughout the autonomous community. Despite the increased activity of vector mosquitoes with the arrival of warmer weather, analyses conducted to date have not detected the virus in mosquitoes, wild birds, or equids.
The Regional Ministry of Health coordinates the information from these control points, which include traps managed by the General Directorate of Public Health and others installed by organizations such as provincial councils and the Doñana Biological Station. The objective is to anticipate potential transmission foci and assess the risk level in each municipality.
Although the analyses are negative, weekly reports indicate an increase in mosquito density in several areas. The highest concentrations have been recorded in La Puebla del Río (Seville), with weekly catches exceeding 1,000 specimens in some traps, and in Montalbán (Córdoba), with figures between 500 and 1,000 mosquitoes. Moderate levels have been detected in municipalities in Cádiz, Huelva, Málaga, and Almería.
Regarding health surveillance in humans, Andalusia has not registered any cases of West Nile fever in 2026. Health services have investigated 58 cases of viral meningitis and conducted studies on 154 individuals to rule out arbovirus infections. No infections have been detected in the 102 analyzed wild birds or in controls on equids.
The current campaign classifies 117 municipalities as high risk, 302 as medium risk, and 366 as low risk. The regions of La Janda (Cádiz) and Bajo Guadalquivir (Seville) are among the areas under special surveillance due to their historical mosquito activity.
The Integrated Surveillance and Control Program for West Nile Fever Vectors is updated with new measures, including genomic sequencing of the virus in human samples and expanded laboratory analyses. Two reference laboratories are consolidated in Seville and Granada. Over 400 Public Health agents collaborate with local councils on pest control plans.
