Italy is currently facing a significant West Nile virus (WNV) outbreak in 2025. As of August 15, there have been 275 confirmed cases and 19 deaths, with a case fatality rate of 15.1%. Among the cases, 126 are neuroinvasive, 125 present with fever, and 11 are asymptomatic. The most affected regions are Lazio and Campania. The virus, transmitted by Culex mosquitoes, circulates seasonally in the country, but this year shows notable expansion.
Comparison with other European countries
- Spain: in 2025, only one case has been reported, in a blood donor from Cáceres (August). However, in 2024, there were 119 cases and 11 deaths, mainly in Andalusia and Extremadura, with confirmed circulation in mosquitoes since July. The most severe outbreak in recent years occurred in 2020, with 71 cases and 8 deaths in Andalusia.
- France: in 2023, reported 39 human cases, mostly in southern regions such as Nouvelle-Aquitaine, Provence-Alpes-Côte d’Azur, and Corsica. Historically, human transmission is concentrated in the Mediterranean belt.
- Greece: since its emergence in 2010, WNV has become endemic, with recurrent outbreaks. In 2022, there were 282 human cases, with sustained circulation every summer, especially in northern rural areas.
Historical context in Italy
Italy has experienced several significant peaks over the past decade:
- 2024: 382 cases and 16 deaths.
- 2023: 336 cases and 29 deaths.
- 2022: recent record with 588 cases and 36 deaths.
- 2018: historic year with 618 cases and 49 deaths.
Prevention and travel risk
There is no vaccine available for West Nile virus in humans. Prevention relies on avoiding mosquito bites (use of repellents, long-sleeved clothing, mosquito nets) and robust epidemiological surveillance. Travelers to affected areas should take extra precautions, especially older adults and people with chronic conditions, due to the higher risk of severe disease.
