Concerns are rising in Spain after five people have died from the West Nile virus, with two more deaths reported in Seville, raising the total to five deaths this year. Travellers and locals have been advised to take precautions such as wearing insect repellant, covering up, and avoiding breeding grounds like stagnant water, particularly between dusk and dawn. Cases of West Nile virus have been reported in several European countries this year, including Austria, Croatia, France, Greece, Hungary, Italy, Romania, and Serbia. These cases were confirmed to have been acquired locally rather than on trips to tropical regions. The European Centre for Disease Prevention and Control (ECDC) also reported dengue fever outbreaks in Europe putting travellers on red alert in the spring.
West Nile virus can cause a fatal neurological disease in humans and belongs to the Japanese encephalitis group of viruses. It is typically spread by mosquitoes and in some cases, through blood transfusion, organ donations, or pregnancy. Symptoms of West Nile fever include sudden high fever, headache, neck stiffness, and a rash on the neck, arms, or legs. In severe cases, symptoms can progress to seizures, muscle weakness, and paralysis. People over the age of 50, especially those with underlying health conditions, are more likely to get seriously ill. Less than 1% of people develop neurological infections such as meningitis or encephalitis, with a fatality rate of 10% in these cases. Symptoms typically appear two to six days after infection but can take up to 14 days or more to develop, and usually ease within three to six days in uncomplicated cases.
There is currently no available vaccine against West Nile virus for humans, so the best way to protect against it is by preventing mosquito bites. This can be done by avoiding affected areas when mosquitoes are more active, such as in the summer, and reducing time spent outdoors in these areas. Using mosquito repellent, covering arms, legs, and feet, and keeping mosquitoes out of living spaces can also help prevent infection. In the event of feeling unwell, especially with a fever, individuals should contact their doctor and inform them of recent travel history. The virus was first detected in Uganda in 1937 and has since spread to various countries across the world, including parts of Africa, the Middle East, Asia, North America, and Europe.
Climate change is contributing to an increase in mosquito-borne illness outbreaks in Europe due to record-high temperatures and extreme weather events. This has created more favorable conditions for invasive mosquitoes to spread into previously unaffected areas and infect more people with diseases like dengue and West Nile virus. The director of the European Centre for Disease Prevention and Control, Andrea Ammon, has warned of the increased risk of imported cases and local outbreaks due to international travel from dengue-endemic countries. The tiger mosquito, which carries dengue, is now established in 13 European countries, and there have been reports of locally acquired cases of West Nile virus in various European regions.
The first large outbreak of West Nile virus in Europe occurred in Romania in 1996, and cases have since been identified in several European countries, including Austria, Croatia, France, Greece, Hungary, Italy, Portugal, Romania, Serbia, and Spain. Recent reports have shown the presence of WNV-carrying mosquitoes in towns near Spain’s Guadalquivir River and various regions in Greece and Italy. In 2023, 713 locally acquired cases of WNV were reported in the EU/EEA, with 67 deaths. The mosquito responsible for transmitting dengue and Zika virus is spreading further north, east, and west in Europe, with recent establishment in Cyprus. The case seen in Spain in March was unusually early, likely due to unseasonably warm weather. ECDC continues to monitor the spread of mosquito-borne illnesses in Europe and advises on preventive measures to reduce the risk of infection.
