Brussels, November 14, 2025 — Cases of infection with the West Nile virus (WNV) have exceeded the threshold of one thousand in Europe in 2025, according to the latest joint report from the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA). Romania reported 49 local cases, remaining among the most affected countries in Central and Eastern Europe.
At the continental level, 1,096 local human cases have been confirmed as of November 5, 2025, in 14 countries, with 95 deaths. The most were recorded in Italy (773 cases, 71 deaths), followed by Greece (95), Serbia (62), France (59), Romania (49), and Spain (31). The cases exceed the average of the last decade (751), but remain below the levels of years with intense virus circulation (2018, 2022, 2024).
For Romania, ECDC notes that the virus remains endemic in the southern and eastern areas, but that in 2025, for the first time, an expansion towards the northwest was reported, with the appearance of a confirmed case in Sălaj County. Experts emphasize that this development reflects climate change and favorable conditions for vector breeding, especially in wet and agricultural areas.
"The persistence of the virus in endemic regions and the emergence of new cases in northern Europe indicate that West Nile is becoming a long-term public health issue," states the joint analysis of ECDC and EFSA. The report warns of the risk that infections may be underreported, as many cases are asymptomatic or diagnosed late.
In 2025, Italy recorded the largest outbreak in its history, with 773 confirmed cases and 71 deaths, mostly in the Lazio and Campania regions. France reported local cases in the Paris region for the first time, while Belgium and the Netherlands identified the first outbreaks in birds, a sign of geographical expansion towards northwestern Europe.
In total, 35 European regions reported West Nile cases for the first time, including urban areas such as Paris, Naples, Palermo, Messina, and Alicante. ECDC also confirms 178 outbreaks in horses and 345 in birds, which represent early indicators of the virus's circulation in the natural environment.
Although the number of cases is decreasing with the end of the warm season, experts warn that the 2025 season was above average and recommend maintaining surveillance measures in 2026. According to the report, the transmission of the West Nile virus is no longer an isolated problem in southern Europe. The geographical expansion confirmed in 2025 necessitates strengthening European cooperation in vector surveillance and in preventing human infections.
The report notes that the transmission season is nearing its end, and only a few sporadic cases are expected until the end of the year. However, European health authorities believe that the virus has definitively established itself in European ecosystems and will continue to reappear seasonally, especially in the context of rising average temperatures and high humidity.