West Nile virus spreads across Europe as Italy reports broadest outbreak yet

The World Health Organization warns of a wider spread of West Nile virus across Europe this summer, with Italy experiencing its most extensive outbreak to date, prompting calls for heightened surveillance and public awareness.

The World Health Organization’s Europe office has warned that West Nile virus is spreading more widely across parts of Europe this summer, with Italy recording the broadest geographical spread of the infection so far.

According to a WHO media release on 24 July, Italy had confirmed 21 cases across 17 areas by 15 July. Greece had reported 21 human cases by 22 July, including 14 in the preceding week, underlining the pace at which transmission can build during peak mosquito season.

The agency said countries should intensify mosquito monitoring and public awareness campaigns, while stressing that most infections remain mild. It added that around one in 150 patients can develop severe disease affecting the central nervous system.

West Nile virus is carried mainly by birds and transmitted to humans through mosquito bites, most often from Culex species. Many infections cause no symptoms at all, while others bring fever, headache, nausea, vomiting, rash or swollen lymph nodes. In rare cases, the illness can progress to encephalitis, meningitis or paralysis.

Italy has long been a focal point for the virus in Europe. Public health data in previous years showed the pathogen spreading across multiple regions and provinces, reinforcing concerns that surveillance and prevention need to remain a summer priority.