European health authorities report 1,855 West Nile virus infections and 141 deaths across 18 countries in 2026, marking record levels for the mosquito-borne illness. Greece accounts for 453 locally acquired cases and 51 deaths through late October, driven by heavy transmission in the Attica region and among elderly patients.
The 2026 transmission season for West Nile virus has pushed human cases and animal outbreaks to unprecedented heights across Europe, according to figures released by the European Food Safety Authority and the European Centre for Disease Prevention and Control. As of early October, 18 European countries documented 1,855 human infections, including 141 deaths. In the European Union and European Economic Area alone, 1,715 cases were reported—dwarfing the 10-year average of 693 cases.
According to Giusi Amore, Scientific Officer in EFSA’s Biological Hazards and Animal Health & Welfare unit, speaking to Reuters, WNV has attained unprecedented levels across Europe in 2026, with human cases and animal outbreaks exceeding all historical counts.
Ole Heuer, Head of Unit at ECDC, noted that the occurrence of the virus varies considerably from year to year and remains difficult to predict, yet ensuring preparedness is achievable. Earlier detection, greater awareness, and effective mosquito control can help reduce the impact of the virus as it spreads to new areas. Céline Gossner, senior expert at ECDC, emphasized that West Nile virus is a clear example of why a cross-sector approach is essential. Because the virus circulates between mosquitoes and birds and can cause disease in people and horses, no single sector can address the risk alone. Authorities in public health, veterinary medicine, and environmental management must collaborate to comprehend the threat and mount a more effective response. Effective mosquito control must combine mosquito monitoring, reduction of breeding sites, and targeted control measures coordinated across these authorities, which, together with personal protection against mosquito bites, helps reduce infection risks.
National Case Counts and Regional Impact Across Europe
The distribution of the virus varies widely by country, with southern Europe bearing the brunt of the outbreak. Italy remains the most severely affected nation with 748 recorded cases. Meanwhile, Greece and France registered their highest numbers ever, logging 445 and 144 human cases respectively.
Recent detections in people and animals in Belgium and the Netherlands demonstrate that the virus is circulating further north, a trend expected to continue in coming years. The Netherlands reported 59 human cases so far this year, while Belgium reported 15 human cases, marking the first locally acquired human West Nile virus infections ever recorded in the country.
Animal surveillance mirrors the human toll. Fifteen European countries recorded 511 outbreaks among equines and 595 outbreaks among bird populations. Although the mosquito transmission season is nearing its end, health officials warn that low-level viral transmission may persist in the coming weeks.
Hellenic National Public Health Organization Tracking 453 Greek Cases
In Greece, where the National Organization of Public Health (EODY) monitors the outbreak, data through October 22 confirms 453 local infections. Of those patients, 283 developed severe neurological manifestations involving the central nervous system—such as encephalitis, meningitis, or acute flaccid paralysis. The remaining 170 individuals experienced mild or asymptomatic infections.
The toll on older adults has been acute. A total of 51 deaths have been recorded in Greece among patients over the age of 35, with a median age of 82 years, ranging from 36 to 92. Younger patients who succumbed to the infection carried a history of severe immunosuppression.
Past records from EODY indicate varying annual figures: 96 cases and 9 deaths for the entirety of 2025, 220 cases and 35 deaths in 2024, and 162 cases with 23 deaths in 2023.
| Reporting Period in Greece | Total Confirmed Cases | Central Nervous System Cases | Deaths |
|---|---|---|---|
| Through October 1, 2026 | 423 | 271 | 41 |
| Through October 15, 2026 | 452 | 283 | 49 |
| Through October 22, 2026 | 453 | 283 | 51 |
High-Risk Municipalities and Asymptomatic Estimates in Greece
Virus transmission has reached 87 municipalities across Greece, including 43 within the Attica region. High-risk transmission zones designated by <a href="https://www.tovima.
- South Athens: Nea Smyrni, Palaio Faliro
- Central Athens: Nea Filadelfia–Nea Chalkidona, Dafni–Ymittos
- Piraeus regional unit: Nikaia–Agios Ioannis Rentis
- Regional units outside Athens: Karditsa (Mouzaki), Trikala (Farkadona), Serres (Amphipolis, Emmanouil Pappas), and the Thessaloniki metropolitan area (Neapoli–Sykies, Pavlos Melas, Oraiokastro, Pylaia–Chortiatis)
Official diagnostic counts capture only a fraction of total infections. Because roughly 80% of infected individuals show no symptoms, and others experience only mild fever, headaches, or body aches, actual community spread is far higher. EODY estimates based on seroepidemiological studies suggest that for every diagnosed case involving neurological complications, approximately 140 people contract the virus without realizing it.
Culex Mosquitoes Spread Virus as Autumn Risks Persist
Transmission occurs primarily through the bites of infected Culex
mosquitoes that acquire the virus from birds, which serve as the natural reservoir. Transmission does not occur directly between humans through casual contact, touching, or kissing.
With autumn weather settling in, health authorities emphasize that the threat has not passed. EODY advises vulnerable populations—particularly the elderly and individuals with chronic illnesses or weakened immune systems—to continue using insect repellent, installing window mosquito nets, wearing long-sleeved clothing, and eliminating standing water around homes in buckets, flower trays, and open containers.
health officials include several densely populated areas where asymptomatic cases are estimated to be significantly higher than the number of confirmed infections recorded during this reporting period.