Dutch health officials have confirmed the country’s fourth locally acquired West Nile virus infection of 2026.
The latest patient is a 39-year-old woman from Amstelveen.
She developed meningitis after contracting the virus. She is the first of the four patients to experience this serious complication.
Meningitis and other neurological problems occur in about 1% of West Nile infections.
Health authorities believe the virus is now circulating in the Netherlands. Infections have been detected in people, birds and horses.
West Nile virus spreads through mosquito bites. Mosquitoes can become infected after feeding on birds carrying the virus.
People and horses cannot normally pass the virus to others.
One locally infected patient from Utrecht recently died in hospital. Another Dutch woman from Drenthe also died after contracting the virus while travelling abroad.
Most people infected with West Nile virus do not become ill.
The Dutch National Institute for Public Health and the Environment says about 80% of infected people experience no symptoms.
Around 19% develop mild symptoms such as fever, headaches, stomach pain, diarrhoea, skin rashes or swollen lymph nodes.
Approximately 1% develop serious neurological conditions. People over 50 and those with weakened immune systems face a higher risk of severe illness.
Despite the new cases, health authorities say the chance of becoming seriously ill remains very low.
