Europe is experiencing its most intense West Nile virus season on record, with locally acquired infections appearing in northern areas that had not previously reported human cases. The European Centre for Disease Prevention and Control (ECDC) says 1,715 cases and 130 deaths had been reported in European Union countries by 7 October 2026.
The figures make this the highest number of locally acquired human West Nile virus infections recorded in the EU. However, the ECDC said the proportion of severe outcomes—including deaths, hospitalisations and neurological illness—remains broadly comparable with the previous decade.
West Nile virus spreads into new European regions
West Nile virus is mainly transmitted to people through the bite of infected mosquitoes. The virus circulates naturally between mosquitoes and birds, but humans and horses can also become infected.
The latest detections in Belgium and the Netherlands indicate that transmission is occurring farther north than previously observed. The ECDC expects this geographical expansion to continue in the coming years, although the intensity of outbreaks can vary significantly from one season to another.
The Netherlands has reported 59 locally acquired human cases in 2026, while Belgium has recorded 15. Belgium’s cases are the first locally acquired human infections reported there, according to the supplied ECDC figures.
Countries reporting the most cases
Southern European countries remain the most affected, but the spread into new regions is changing the geographical picture of West Nile virus in Europe.
- Italy: 748 reported cases
- Greece: 445 cases, its highest recorded number
- France: 144 cases, also a record
- The Netherlands: 59 cases
- Belgium: 15 cases, the country’s first locally acquired human infections
The figures cover locally acquired infections reported in EU countries up to 7 October 2026. They do not mean that every mosquito in the affected countries carries the virus, nor do they indicate that all infections result in serious illness.
What the record figures mean for public health
Many people infected with West Nile virus develop no symptoms or experience only mild illness. Severe disease is more likely to affect older adults and people with weakened immune systems. Serious infection can involve neurological symptoms and may require hospital treatment.
Despite the record number of cases, the ECDC said the number of deaths, hospitalisations and neurological cases is not higher in proportion than during the previous decade. This distinction is important: the virus is reaching more people and more locations, but the available information does not show that the illness has become more severe overall.
There is currently no licensed human vaccine for West Nile virus. Treatment focuses on managing symptoms, with supportive hospital care used for severe infections.
Why mosquito control and surveillance matter
The ECDC is calling for stronger preparedness as the virus establishes itself in areas where it has not previously been detected. Because West Nile virus affects mosquitoes, birds, people and horses, health authorities need cooperation across several areas rather than relying on human healthcare services alone.
Useful public-health measures include:
- Earlier detection of infections in people and animals
- Monitoring mosquito populations and bird infections
- Effective mosquito-control programmes
- Clear public information during periods of heightened risk
- Improved awareness among clinicians in newly affected regions
The timing and scale of outbreaks are difficult to predict. Weather conditions, mosquito activity, bird movements and local environmental factors can all influence transmission from year to year.
How people can reduce the risk
People living in or visiting affected areas can lower their exposure to mosquito bites by taking practical precautions, particularly during periods of mosquito activity.
- Use an effective mosquito repellent.
- Wear loose-fitting clothing that covers the arms and legs.
- Use window screens, mosquito nets or air conditioning where available.
- Follow advice from national and local public-health authorities.
- Seek medical advice if symptoms develop after possible exposure, especially where there is fever or neurological illness.
These measures are particularly important for older people and those with weakened immune systems, who face a greater risk of severe disease.
What happens next in Europe?
The ECDC’s warning is primarily a call for readiness rather than an announcement of a new EU-wide emergency measure. National health authorities remain responsible for local surveillance, mosquito control and public-health advice, while European monitoring helps identify changes in transmission across borders.
For Ireland, the immediate relevance is mainly preparedness and surveillance. Ireland has not been identified in the supplied figures as a country with locally acquired cases, but the northward movement of mosquito-borne disease highlights the importance of monitoring changing European health risks and following advice from public-health authorities.
The current season shows why West Nile virus must be treated as a cross-sector European health issue. Record case numbers, newly affected regions and continued uncertainty about future seasons make early detection and mosquito-control planning central to limiting its impact.
Conclusion
The latest West Nile virus data confirm a record season across the EU, with 1,715 locally acquired cases and 130 deaths reported by 7 October 2026. The spread into Belgium and the Netherlands is a significant warning about the changing geography of mosquito-borne disease, even though severe outcomes remain comparable with the past decade. Better surveillance, public awareness and mosquito control will be essential as European health authorities prepare for future seasons.
