West Nile Virus Europe: 1,086 Cases in 2026 | Guide

More than 1,000 people across Europe have been infected with the West Nile virus during the 2026 mosquito season, according to new surveillance data from the European Centre for Disease Prevention and Control (ECDC). As of the agency's Week 36 report published on 4 September 2026, 1,086 locally acquired human cases had been confirmed in 15 European countries, marking a sharp acceleration of a disease once confined to the Mediterranean.

What Is the West Nile Virus?

West Nile virus (WNV) is a mosquito-borne flavivirus that circulates primarily among wild birds. It is transmitted to humans and other mammals when a common house mosquito (Culex pipiens) feeds first on an infected bird and then bites a person. Humans are considered dead-end hosts, meaning the virus is not passed from person to person. The climate-driven spread of mosquito-borne diseases has made WNV an increasingly familiar public health concern in Europe.

2026 European Outbreak by the Numbers

The ECDC's latest weekly bulletin shows the highest case burden in southern Europe, with Italy accounting for nearly half of all infections.

• Italy: 516 cases
• Greece: 284 cases
• Spain: 88 cases
• Romania: 56 cases

France has reported 13 affected areas, while the virus has also been detected in North Macedonia and several other nations. The ECDC notes that 144 affected areas have been identified across the 15 countries since the transmission season began, with 20 new areas reported in the first week of September alone.

Netherlands Reports Local Infections and Death

The Dutch public health institute RIVM confirmed that at least nine people contracted the virus locally in the Netherlands this year. One of them, a 75-year-old Utrecht resident with an underlying health condition, died. A woman from Drenthe also died after being infected in Southeast Europe, but she is not counted among the nine domestic cases because her exposure occurred abroad.

In August 2026, the virus was detected in the Netherlands for the first time since 2020 during a scientific study by blood bank Sanquin among blood donors. This finding has prompted closer monitoring of blood supplies under EU safety rules.

Symptoms and Who Is Most at Risk

Health authorities including the World Health Organization mosquito surveillance guidance emphasize that most infections are mild or invisible. According to RIVM and WHO data:

• 80% of infected people develop no symptoms.
• About 19% experience mild, flu-like illness with fever, headache and muscle pain.
• Roughly 1% develop severe neurological disease such as encephalitis or meningitis.

Older adults and people with weakened immune systems or underlying conditions face the highest risk of severe outcomes. The virus is most active in Europe between July and September.

How to Protect Yourself from West Nile Virus

Because there is no human vaccine or specific antiviral treatment for West Nile virus, prevention focuses on avoiding mosquito bites.

1. Wear long-sleeved clothing and long trousers, especially at dawn and dusk.
2. Apply insect repellent containing DEET or another approved ingredient.
3. Use window screens and mosquito nets indoors.
4. Remove standing water around homes where mosquitoes breed.
5. Limit outdoor activity during peak mosquito hours.

Why Are Cases Rising in Europe?

Warmer temperatures and longer summers are expanding the range and activity of Culex mosquitoes across the continent. The 2026 European mosquito season has started earlier and spread into regions where WNV was previously rare, reinforcing calls from the ECDC and WHO for stronger surveillance and public awareness.

Frequently Asked Questions

How many West Nile virus cases are there in Europe in 2026?

As of 4 September 2026, the ECDC reported 1,086 locally acquired cases across 15 European countries.

Which European country has the most West Nile virus cases?

Italy leads with 516 confirmed cases, followed by Greece with 284 and Spain with 88.

Can West Nile virus be transmitted from person to person?

No. The virus spreads only through the bite of an infected mosquito; humans are dead-end hosts.

What are the symptoms of West Nile virus?

About 80% of people have no symptoms. Others may develop fever, headache and muscle pain; around 1% can develop severe neurological illness.

Is there a West Nile virus vaccine?

No human vaccine or antiviral treatment exists, so mosquito-bite prevention is essential.