Europe mosquito-borne disease data

The first human West Nile virus case of the 2026 season in the European Region was reported in the Vardar region of North Macedonia — one locally-acquired case — per the ECDC weekly West Nile virus surveillance report dated 3 June 2026. At season opening (week 23) North Macedonia was the only European country reporting a 2026 human WNV case.

Source: ECDC · Surveillance of West Nile virus infections in humans in Europe (weekly report, 3 June 2026) · verified 10 June 2026

Italy recorded the most human West Nile virus cases in the EU/EEA in 2025 — 779 confirmed cases — the largest single-country WNV total in the region that year, concentrated in Lombardia, Veneto and Emilia-Romagna.

Source: Istituto Superiore di Sanità (ISS) · verified 25 May 2026

Italy reported 72 West Nile virus deaths in 2025 — a case fatality rate of 9.2% across 779 confirmed cases — the highest national WNV death toll in the EU/EEA that season.

Source: Istituto Superiore di Sanità (ISS) · verified 25 May 2026

France had the largest autochthonous chikungunya outbreak in continental Europe in 2025 — 809 locally-acquired cases across 79 transmission episodes (1 May – 30 November), with symptom onset between 27 May and 13 November. It was the largest continental-European autochthonous CHIKV outbreak on record for that year.

Source: Santé publique France · enhanced arbovirus surveillance · verified 25 May 2026

Italy reported 384 autochthonous (locally-acquired) chikungunya cases in 2025 across four regions — Emilia-Romagna, Veneto, Toscana and Lazio — out of 472 total cases including travel-imported ones, with no deaths. All Italian and French CHIKV clusters were declared closed by the end of 2025.

Source: Istituto Superiore di Sanità (ISS) · verified 31 May 2026

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