Deadly West Nile virus sweeps Europe as southern Mediterranean expects heat dome

The deadly West Nile virus is rapidly spreading across Europe as mosquitoes thrive due to global warming, according to the most recent data from the European Centre for Disease Prevention and Control. Cases of the virus have surged by nearly 50% compared to the previous year, with Italy and Greece accounting for the majority of occurrences.

The disease is also spreading northwards, with a fatality reported in the Netherlands on Wednesday following a person's infection. The Dutch public health institution RIVM recently noted the first case of West Nile virus in the country since 2020.

The virus, primarily transmitted through mosquito bites, can lead to severe illness in approximately one in every 150 infected individuals, as reported by the World Health Organisation. Warmer temperatures are providing mosquitoes with more time and territory to spread the virus across Europe. Currently, about 99 areas in 12 countries are affected by the West Nile Virus. Italy has reported 46 cases, Greece 17, Romania 14, and France 8.

In August 2025, 67 areas and nine countries were impacted by the virus, as per the ECDC. The West Nile virus is primarily transmitted by the Culex mosquito, with the Asian tiger mosquito also serving as a carrier of dengue fever, a second carrier in Europe since the early 2000s. This week, German authorities reported that two airport workers died after six staff members were infected by the Anopheles mosquito, which was introduced by aircraft.

The Robert Koch Institute suggests that heat could be contributing to the local transmission, given the scale of the outbreak that began in early July. None of the workers had visited malaria-risk countries.

Europe, which is warming more than twice as fast as the global average, is experiencing a scorching summer that has resulted in at least 35,000 excess deaths, with figures expected to rise further. France, Spain, and Germany alone have recorded 25,000 excess deaths. High temperatures returned to Italy on Friday, with forecasts of 37°C in Rome and 46°C in Sicily. A heatwave has also gripped Greece, with temperatures reaching 40°C in the north.