Europe disease surveillance
West Nile virus in Europe, 2025-2026 case data
In 2025, Italy reported the most West Nile virus cases of any EU/EEA country, 779 cases and 72 deaths, ahead of Greece (96) and France (62). The 2026 season's first human case in Europe was reported in North Macedonia (Vardar). Figures cover the countries Mosticare tracks (updated 27 July 2026); ECDC publishes the full EU/EEA total.
Last updated · 27 July 2026 · CC BY 4.0
Key facts
The first human West Nile virus case of the 2026 season in the European Region (EU/EEA + neighbourhood) was reported in the Vardar region of North Macedonia, one locally-acquired case, first appearing in the ECDC weekly West Nile virus surveillance report dated 3 June 2026. As of ECDC Week 29/2026 (data to 15 July 2026), the European Region total has risen to 5 countries, 34 locally-acquired human cases and 28 affected areas: Italy 21 (the mainland EU/EEA leader, up from 6 at W28), Greece 7 (up from 1), North Macedonia 2, Romania 2 and Spain 2 (up from 1). North Macedonia is an EU candidate country included in ECDC's weekly EU/EEA-and-neighbourhood WNV surveillance.
Source: ECDC · Surveillance of West Nile virus infections in humans in Europe (weekly report, Week 29/2026, data to 15 July 2026) · verified 27 July 2026
Italy recorded the first mainland EU/EEA West Nile virus case of the 2026 season, first detected at the ECDC Communicable Disease Threats Report Week 27 reading (data to 1 July 2026): three locally-acquired cases across three NUTS3 sub-areas, IT Caserta (NUTS3 ITF31, Campania), IT Firenze (NUTS3 ITI14, Toscana) and a W27-additional NUTS3 area. Italy has since risen to 21 locally-acquired human cases at ECDC Week 29 (data to 15 July 2026), leading the European Region (which stands at 34 cases across 5 countries and 28 affected areas). The 2026 Piano Nazionale Arbovirosi integrated surveillance is in force; the ISS national bulletin with the per-NUTS3 W29 breakdown remains pending, so the sub-area detail is the last-confirmed W27 set.
Source: ECDC · Surveillance of West Nile virus infections in humans in Europe (weekly report, Week 29/2026, data to 15 July 2026); first-detection context from ECDC CDTR Week 27 (data to 1 July 2026) · verified 27 July 2026
Italy recorded the most human West Nile virus cases in the EU/EEA in 2025, 779 locally-acquired cases per ECDC's end-of-season cross-country report (data to 3 December 2025), the largest single-country WNV total in the region that year, concentrated in Lombardia, Veneto and Emilia-Romagna. Italy's own ISS integrated surveillance recorded 773 confirmed cases (770 autochthonous) as of its final 30 October 2025 bulletin, with the consolidated 2025 summary still pending.
Source: ECDC · Surveillance of West Nile virus infections in Europe (cross-country, data to 3 Dec 2025); Istituto Superiore di Sanità (ISS) for national detail · verified 15 June 2026
Greece had the second-most human West Nile virus cases in the EU/EEA in 2025, 96 locally-acquired cases (76 of them neuro-invasive) and 9 deaths, behind only Italy (779). Attica was the main hotspot. The figures are EODY/NPHO's final 2025 count, consistent with ECDC's cross-country report.
Source: EODY · National Public Health Organization (NPHO), Greece · verified 14 June 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
Romania was among the first EU/EEA-and-neighbourhood countries to report 2026 autochthonous West Nile virus cases, 2 locally-acquired cases (both within the 2 June to 30 October 2026 enhanced-surveillance window, 0 deaths), and holds at 2 through the ECDC Week 29 reading (data to 15 July 2026). Romania no longer leads the European count: at Week 29 Italy leads with 21 cases and Greece is second with 7, within a European Region total of 34 locally-acquired human cases across 5 countries and 28 affected areas (Italy 21, Greece 7, North Macedonia 2, Romania 2, Spain 2). Romania was a new 2026 reporting country (0 cases through W26, 2 from W27); the ECDC weekly directs readers to the joint monthly report at https://wnv-monthly.ecdc.europa.eu/ for the county/NUTS3 breakdown. INSP/CNSCBT weekly informer corroborates both RO cases as autochthonous.
Source: ECDC · Surveillance of West Nile virus infections in humans in Europe (weekly report, Week 29/2026, data to 15 July 2026); Institutul Național de Sănătate Publică (INSP) · CNSCBT weekly informer · verified 27 July 2026
The first 2026 autochthonous (locally acquired) human West Nile virus case in metropolitan France was reported in the Pyrénées-Orientales département (Occitanie). Santé publique France's national reinforced arbovirus bulletin of 23 July 2026 (data to 20 July 2026) recorded 1 locally-acquired human WNV case there, 0 deaths, the first of the metropolitan-France 2026 season. It is SpF-sourced and not yet reflected in the ECDC weekly WNV report (which at Week 29, data to 15 July 2026, lists Italy 21, Greece 7, North Macedonia 2, Romania 2 and Spain 2); France would become the sixth ECDC-reporting country when the case is picked up. WNV is transmitted by Culex mosquitoes; most human infections are silent, and there is no licensed human vaccine or specific antiviral, so avoiding bites is the primary individual defence.
Source: Santé publique France · national reinforced arbovirus bulletin (chikungunya-dengue-Zika et-17, 23 July 2026, data to 20 July 2026) · verified 27 July 2026
West Nile virus in Europe over time (2016-2025)
Reported West Nile virus cases in the EU/EEA swing sharply from one summer to the next rather than rising in a straight line. Between 2016 and 2025, EU/EEA Member States reported between 141 locally-acquired human cases (2021) and 1,548 (2018) a year, averaging about 689. Each of the last 4 seasons (2022-2025) has been above that 2016-2025 average, so the burden has been elevated and geographically wider in recent years, though 2018 remains the peak. Figures are reported locally-acquired (autochthonous) human cases in EU/EEA Member States per ECDC. Year-to-year comparisons are affected by changes in surveillance intensity, case definitions and the set of reporting countries; West Nile virus activity is strongly driven by summer weather and varies sharply between seasons. ECDC is the primary surveillance authority for the complete European total.
The data
About West Nile virus
West Nile virus (WNV) is the most widespread mosquito-borne disease in continental Europe. It is transmitted by Culex mosquitoes, mainly Culex pipiens, the common house mosquito, which bridge from birds to humans during late-summer urban swarms. Most human infections are mild or symptom-free; a small share progress to neuro-invasive disease, which carries the mortality risk. The European transmission window runs roughly from week 22 to week 43 (early June to late October).
Frequently asked questions
What was the first West Nile virus case in Europe in 2026?
The first human West Nile virus case of the 2026 season in the European Region (EU/EEA + neighbourhood) was reported in the Vardar region of North Macedonia, one locally-acquired case, first appearing in the ECDC weekly West Nile virus surveillance report dated 3 June 2026. As of ECDC Week 29/2026 (data to 15 July 2026), the European Region total has risen to 5 countries, 34 locally-acquired human cases and 28 affected areas: Italy 21 (the mainland EU/EEA leader, up from 6 at W28), Greece 7 (up from 1), North Macedonia 2, Romania 2 and Spain 2 (up from 1). North Macedonia is an EU candidate country included in ECDC's weekly EU/EEA-and-neighbourhood WNV surveillance.
Which country had the first mainland EU/EEA West Nile virus case in 2026?
Italy recorded the first mainland EU/EEA West Nile virus case of the 2026 season, first detected at the ECDC Communicable Disease Threats Report Week 27 reading (data to 1 July 2026): three locally-acquired cases across three NUTS3 sub-areas, IT Caserta (NUTS3 ITF31, Campania), IT Firenze (NUTS3 ITI14, Toscana) and a W27-additional NUTS3 area. Italy has since risen to 21 locally-acquired human cases at ECDC Week 29 (data to 15 July 2026), leading the European Region (which stands at 34 cases across 5 countries and 28 affected areas). The 2026 Piano Nazionale Arbovirosi integrated surveillance is in force; the ISS national bulletin with the per-NUTS3 W29 breakdown remains pending, so the sub-area detail is the last-confirmed W27 set.
Which European country had the most West Nile virus cases in 2025?
Italy recorded the most human West Nile virus cases in the EU/EEA in 2025, 779 locally-acquired cases per ECDC's end-of-season cross-country report (data to 3 December 2025), the largest single-country WNV total in the region that year, concentrated in Lombardia, Veneto and Emilia-Romagna. Italy's own ISS integrated surveillance recorded 773 confirmed cases (770 autochthonous) as of its final 30 October 2025 bulletin, with the consolidated 2025 summary still pending.
Which European country had the second-most West Nile virus cases in 2025?
Greece had the second-most human West Nile virus cases in the EU/EEA in 2025, 96 locally-acquired cases (76 of them neuro-invasive) and 9 deaths, behind only Italy (779). Attica was the main hotspot. The figures are EODY/NPHO's final 2025 count, consistent with ECDC's cross-country report.
How many people died of West Nile virus in Italy in 2025?
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.
How many 2026 West Nile virus cases has Romania reported, and does it lead the European count?
Romania was among the first EU/EEA-and-neighbourhood countries to report 2026 autochthonous West Nile virus cases, 2 locally-acquired cases (both within the 2 June to 30 October 2026 enhanced-surveillance window, 0 deaths), and holds at 2 through the ECDC Week 29 reading (data to 15 July 2026). Romania no longer leads the European count: at Week 29 Italy leads with 21 cases and Greece is second with 7, within a European Region total of 34 locally-acquired human cases across 5 countries and 28 affected areas (Italy 21, Greece 7, North Macedonia 2, Romania 2, Spain 2). Romania was a new 2026 reporting country (0 cases through W26, 2 from W27); the ECDC weekly directs readers to the joint monthly report at https://wnv-monthly.ecdc.europa.eu/ for the county/NUTS3 breakdown. INSP/CNSCBT weekly informer corroborates both RO cases as autochthonous.
Where was the first locally acquired West Nile virus case in metropolitan France in 2026?
The first 2026 autochthonous (locally acquired) human West Nile virus case in metropolitan France was reported in the Pyrénées-Orientales département (Occitanie). Santé publique France's national reinforced arbovirus bulletin of 23 July 2026 (data to 20 July 2026) recorded 1 locally-acquired human WNV case there, 0 deaths, the first of the metropolitan-France 2026 season. It is SpF-sourced and not yet reflected in the ECDC weekly WNV report (which at Week 29, data to 15 July 2026, lists Italy 21, Greece 7, North Macedonia 2, Romania 2 and Spain 2); France would become the sixth ECDC-reporting country when the case is picked up. WNV is transmitted by Culex mosquitoes; most human infections are silent, and there is no licensed human vaccine or specific antiviral, so avoiding bites is the primary individual defence.
How many West Nile virus cases were reported in Europe in 2025?
Across the countries Mosticare tracks, 2025 West Nile virus cases were: Italy 779, Greece 96, France 62, Serbia 62, Romania 49, Spain 36, Hungary 14, Croatia 4, Albania 3, Germany 2, North Macedonia 2, Bulgaria 1, Kosovo 1, Türkiye 1. These are national totals from each country's health authority; for the complete EU/EEA figure, ECDC's surveillance is the primary source.
How many West Nile virus cases have been reported in Europe in 2026?
So far in the 2026 season the tracked countries report: France 1, Spain 2, North Macedonia 2, Greece 7, Romania 2. The feed is refreshed weekly during transmission season; ECDC publishes the full EU/EEA running total.
Which mosquito transmits West Nile virus in Europe?
West Nile virus is transmitted in Europe by Culex pipiens (Northern house mosquito). Native across all of Europe. Night feeder, prefers birds but bridges to humans during late summer urban swarms.
When is West Nile virus season in Europe?
The continental-European West Nile virus transmission window runs approximately from week 22 to week 43, early June to late October, peaking in late summer. Surveillance plans in Italy, France and Spain reactivate at the start of this window each year.
Is West Nile virus increasing in Europe?
Reported West Nile virus cases in the EU/EEA swing sharply from one summer to the next rather than rising in a straight line. Between 2016 and 2025, EU/EEA Member States reported between 141 locally-acquired human cases (2021) and 1,548 (2018) a year, averaging about 689. Each of the last 4 seasons (2022-2025) has been above that 2016-2025 average, so the burden has been elevated and geographically wider in recent years, though 2018 remains the peak. Figures are reported locally-acquired (autochthonous) human cases in EU/EEA Member States per ECDC. Year-to-year comparisons are affected by changes in surveillance intensity, case definitions and the set of reporting countries; West Nile virus activity is strongly driven by summer weather and varies sharply between seasons. ECDC is the primary surveillance authority for the complete European total.
How many West Nile virus cases were reported in Europe each year from 2016 to 2025?
Locally-acquired human WNV cases in EU/EEA Member States by year, 2016: 225, 2017: 201, 2018: 1,548, 2019: 425, 2020: 316, 2021: 141, 2022: 1,113, 2023: 709, 2024: 1,171, 2025: 1,043. The peak was 2018 (1,548) and the lowest year was 2021 (141). For 2024 and 2025 ECDC's wider "Europe" headline (including EU-neighbouring countries) was higher (1,436 and 1,112). Source: ECDC; year-to-year comparisons are affected by changes in surveillance and case definitions.
How many West Nile virus cases were there in Europe in the last five years?
Locally-acquired human WNV cases in EU/EEA Member States, last five seasons, 2021: 141, 2022: 1,113, 2023: 709, 2024: 1,171, 2025: 1,043. ECDC is the primary source for the complete European total.
What was the worst year for West Nile virus in Europe?
2018 was the worst recorded European West Nile virus season, with 1,548 locally-acquired human cases in EU/EEA Member States, which ECDC attributed to an exceptionally warm summer. The lowest recent year was 2021 (141). Year-to-year comparisons are affected by changes in surveillance and case definitions.
Sources
- Santé publique France, bilan national West Nile 2025 (édition nationale, deaths); ECDC for the cross-country case count (data to 3 Dec 2025)
- Istituto Superiore di Sanità (ISS), deaths + integrated WNV/Usutu surveillance; ECDC for the cross-country case count (data to 3 Dec 2025)
- Junta de Andalucía · Consejería de Salud y Consumo
- RENAVE · Centro Nacional de Epidemiología (ISCIII), final 2025 national report (deaths); ECDC for the cross-country case count (data to 3 Dec 2025)
- EODY · National Public Health Organization (NPHO), Greece
- Institut za javno zdravlje Srbije „Dr Milan Jovanović Batut“
- Institutul Național de Sănătate Publică (INSP) · CNSCBT
- Nemzeti Népegészségügyi és Gyógyszerészeti Központ (NNGYK)
- ECDC · Surveillance of West Nile virus infections in Europe (monthly report, data to 3 December 2025)
- Santé publique France · national reinforced arbovirus bulletin (chikungunya-dengue-Zika et-17, 23 July 2026)
- ECDC · Surveillance of West Nile virus infections in humans in Europe (weekly report)
- Junta de Andalucía · Consejería de Sanidad, Presidencia y Emergencias
- European Centre for Disease Prevention and Control (ECDC), 2025 end-of-season West Nile virus surveillance (data to 3 December 2025)
- Public Health Center of the Ministry of Health of Ukraine; Deputy Minister of Health & Chief Sanitary Doctor Ihor Kuzin
- National Center for Disease Control and Prevention (NCDC) / Ministry of Health of Armenia, reported via ARMENPRESS
- Samoilova TI, Votiakov VI, Titov LP, Central European Journal of Public Health (2003)
- European Centre for Disease Prevention and Control (ECDC)
- Rospotrebnadzor (Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing), surveillance review, Putintseva et al., 2025
- Hubálek & Halouzka, Emerging Infectious Diseases (US CDC), 1999, WNV reported from Azerbaijan; no national autochthonous case count is published
- National Center for Disease Control and Public Health of Georgia (NCDC)
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About this data
Mosticare aggregates and re-publishes vector-borne disease surveillance from ECDC, EFSA, and national ministries of health. Mosticare is an aggregator, not a primary surveillance authority, every figure on this page cites the originating source and is independently verifiable. This is a partial aggregation; for the complete EU/EEA totals, ECDC is the primary source.
The data behind this page is published as free, machine-readable feeds under CC BY 4.0, the point-in-time incidence snapshot at /threat-map/feed.json (JSON Schema) and the multi-year trends at /threat-map/feed/trends.json (JSON Schema). See the live Europe threat map and the full data room.