Spain is grappling with a concerning surge in West Nile virus (WNV) cases, with the death toll reaching five this year. Two recent fatalities in Seville have heightened concerns about the virus’s spread. Health officials are urging both residents and visitors to take proactive steps to prevent mosquito bites, the primary mode of transmission.
Key recommendations include using insect repellent, wearing long sleeves and pants, especially during dawn and dusk when mosquitoes are most active, and avoiding stagnant water. The virus has also been reported in several other European countries, including Austria, Croatia, France, Greece, Hungary, Italy, Romania, and Serbia. The European Centre for Disease Prevention and Control (ECDC) has confirmed that these cases were acquired locally, not through travel to tropical regions.
West Nile virus is known to cause severe neurological diseases and belongs to the Japanese encephalitis virus group, which also includes dengue and yellow fever. While birds are natural hosts, mosquitoes serve as the primary carriers. Transmission can occur through blood transfusions, organ donations, or from mother to child during pregnancy, though these occurrences are rare.
Approximately 80% of WNV infections are asymptomatic. For the remaining 20%, symptoms may develop into West Nile fever, characterized by high fever, headache, neck stiffness, and a rash on the neck, arms, or legs. In severe cases, neurological complications such as seizures, muscle weakness, and paralysis can occur. Older adults and individuals with pre-existing health conditions are at a higher risk for severe illness.
Severe neurological infections like meningitis or encephalitis occur in less than 1% of cases, with about 10% of these proving fatal. Symptoms typically appear within two to six days after infection, but can take up to 14 days. Most cases resolve within three to six days without complications. There is currently no vaccine available for WNV, making prevention crucial. Avoiding travel to high-risk areas during mosquito season and minimizing outdoor exposure can help reduce the risk of infection.
