West Nile cases surge in Italy as health officials stress mosquito control

Italy’s West Nile virus infections more than doubled over the past three years, reaching 773 confirmed cases in 2025 – a 133 % increase from 2023. The outbreak spread to almost every region, with the highest numbers in Lazio (87 cases), Campania (83) and Lombardy (56). Of the 2025 cases, 367 were neuro‑invasive and 339 presented as fever, including three imported infections from Kenya, Egypt and the Maldives.

Extensive screening of blood, organ, tissue and cell donations prevented any transmission to recipients. The safety program identified 56 asymptomatic blood donors and two organ donors carrying the virus, who were excluded from donation.

Entomologists note that around 40 mosquito species inhabit Italy, with the tiger mosquito (Aedes albopictus) and the common house mosquito (Culex pipiens) being the most relevant vectors for West Nile and Dengue. “L’uomo può ammalarsi, ma non può trasmettere il virus ad altri perché è un ‘binario morto’,” explained Roberto Pantaleoni.

Health authorities advise local administrations to map risk areas, monitor larval presence and eliminate standing water, while citizens are urged to use screens, repellents and remove water‑collecting containers to curb mosquito breeding.