:INFO
650 infections, 17 dead, and the season still has weeks left
Italy has recorded more than 650 West Nile virus infections in 2026 and 17 deaths, accounting for roughly half of all cases logged across Europe this year. In 2025 the full season produced 779 confirmed cases and 72 deaths. At the current rate, 2026 is on course to match or exceed that total before October. The ECDC published its most recent monthly surveillance report on August 5, 2026, covering 245 locally acquired human cases across seven European countries as of that date. Italy held the largest share then, as it does now. West Nile has been considered endemic in Italy since 2020, when cases began to rise sharply every summer. It is no longer a disease of isolated outbreaks. It is a permanent feature of Italian summers, and the boundaries of that summer are expanding.

:STATS
[icon:USERS] West Nile cases in Italy so far in 2026 | 650+ confirmed
[icon:FIRE] Deaths from West Nile in Italy in 2026 | 17
[icon:CHART] Full-year Italy total in 2025 | 779 cases, 72 deaths
[icon:TARGET] Italy's share of all European cases in 2026 | roughly 50%
[icon:TARGET] Italian regions with confirmed virus circulation | 12 of 20
[icon:TARGET] Italian provinces with confirmed virus circulation | 47
[icon:USERS] European countries reporting West Nile cases in 2026 | 7
[icon:CLOCK] Year Italy declared West Nile virus endemic | 2020

:LINK
https://pmc.ncbi.nlm.nih.gov/articles/PMC13482765/
ECDC and EFSA: Monthly West Nile virus surveillance report, August 5 2026 (primary source)

:INFO
The season starts earlier, runs later, and goes further north
The twelve Italian regions with confirmed virus circulation in 2026 run from Piedmont in the northwest to Sicily in the south, including Lombardy, Veneto, Emilia-Romagna and Lazio. The 47 affected provinces include areas rarely touched five years ago. Culex pipiens, the common house mosquito and primary West Nile carrier in Europe, breeds faster and bites more frequently as temperatures rise. Warmer springs allow colonies to establish earlier; milder autumns delay the end of the transmission season. The Netherlands recorded more than 20 locally acquired West Nile cases in 2026, the first there since 2020. A Belgian research team visited Italy's National Institute of Health in May to study its surveillance model after Belgium began recording its own locally acquired cases. The virus is moving north.

:QUOTE [quotetype:plain, subtitle:Antonino Bella · Researcher at Italy's National Institute of Health]
Higher temperatures linked to climate change help mosquitoes reproduce and extend the transmission season, increasing the chances that infected mosquitoes will spread the virus to people.

:INFO
What the disease actually does
About 80% of those infected develop no symptoms at all. In most of the remaining 20% the illness resembles a mild flu: fever, headache, fatigue, body aches, sometimes a rash. The danger is concentrated in the roughly 1% who develop neuroinvasive disease, encephalitis or meningitis, which carries a high case fatality rate particularly among the elderly and the immunocompromised. Italy's 2025 neuroinvasive case fatality rate was 9.2%. There is no approved human vaccine. Prevention rests entirely on reducing mosquito exposure: repellents, protective clothing, draining standing water, and the municipal spraying programmes Italian regions run each summer.

:LINK
https://www.ecdc.europa.eu/en/infectious-disease-topics/west-nile-virus-infection/surveillance-and-updates-west-nile-virus
ECDC: West Nile virus surveillance and updates, 2026 season

:QUOTE [quotetype:plain, subtitle:Marc-Alain Widdowson · Pandemic Threats Division at WHO Europe]
There's no doubt that warming weather will expand the period of replication for the virus.

:INFO
Italy's experience is a preview for the rest of Europe
Francesco Severino, a senior researcher in medical entomology at the ISS, has tracked invasive mosquito species across Europe for over a decade. Thirteen European countries now have established populations of Aedes albopictus (the tiger mosquito), up from eight a decade ago. The number of European regions with invasive mosquito populations has grown from 114 to 337 in the same period. For now, Culex pipiens drives most Italian West Nile transmission. But the broader expansion of mosquito habitat signals how much the baseline has shifted. Italy's burden, half of all European cases from a country with strong surveillance and established public health infrastructure, is not exceptional. It is the clearest current data point on what warming summers mean for vector-borne disease in the northern hemisphere.

:LINK
https://www.ecdc.europa.eu/en/infectious-disease-topics/west-nile-virus-infection/surveillance-and-disease-data/monthly-updates
ECDC: Monthly West Nile virus seasonal surveillance updates, 2026