Andalusia confirms fifth West Nile fever case, extends alert to 15 municipalities as new areas declared

Fifth case confirmed in Coria del Río

A man residing in Coria del Río (Seville) developed symptoms on 17 July and tested positive for West Nile virus via PCR at the Hospital Universitario Virgen del Rocío on 24 July, the Andalusian health department confirmed. The case is mild and brings the total number of human West Nile fever infections in Andalusia this season to five. All five cases have been recorded in Seville province. The two most recent prior cases were two women in La Puebla del Río, who showed symptoms on 19 and 20 July and were confirmed on 23 July. The first two cases of the season were identified in Palomares del Río and Villamanrique de la Condesa. All cases were detected through the regional vector surveillance programme, which targets residents and visitors in high-risk municipalities who present compatible symptoms.

Alert areas expanded across the region

Following the new case, the health authority extended the alert period for Coria del Río until 14 August. La Puebla del Río's alert status was already prolonged to 17 August after the two cases there. Additionally, the regional government declared new alert areas due to virus circulation in mosquitoes: Bollullos de la Mitación (Seville), Fuengirola (Málaga), the Las Lagunas district of Mijas (Málaga), and Salobreña (Granada). These declarations last a minimum of four weeks or until no further cases or virus detections occur. Andalusia now has 15 municipalities under alert, according to the latest update, including Pulpí (Almería), Torredonjimeno (Jaén), and several towns in Seville such as Almensilla, Aznalcázar, and Coria del Río. The alert status triggers intensified entomological, animal, and human surveillance, community outreach through pharmacies and nursing services, and mandatory mosquito control measures by local councils. These include treatment of larval sites and adult mosquito refuges within a 1.5 km radius of population centres, as stipulated in each municipality's vector control plan.

2024 outbreak remains a stark reference point

The current figures are far below the severe 2024 season, when Spain recorded 158 human West Nile cases, 118 of them in Andalusia and 102 in Seville province alone. Ten people died in Seville province that year, sparking neighbourhood protests and a broad political debate over mosquito control. In 2025, reinforced prevention measures helped keep numbers low: Spain reported 45 cases (37 confirmed, 8 probable), with only two in Seville province. The five cases so far in 2026 already double the 2025 Seville total, but health officials note that all have been mild and detected through the active surveillance programme.

Prevention and expert warning

After the 2024 crisis, authorities strengthened their response with a regional vector control programme, a provincial fumigation plan covering 15 high-risk municipalities, and local action plans. The current surveillance system, which identified all five cases, targets residents and visitors in high-risk areas who show symptoms. At a conference in Seville last October, Jordi Figuerola Borrás, a researcher at the Doñana Biological Station (CSIC), warned that the virus is not a temporary threat.

West Nile virus is not a passing problem; it has come to stay.

He described it as an ongoing public health challenge requiring sustained prevention efforts.