West Nile virus cases rise in the Netherlands

The West Nile virus is circulating in the Netherlands, with at least nine human infections reported this year. According to the National Institute for Public Health and the Environment (RIVM), cases have been identified in Utrecht (5), South Holland (2), North Holland (1), and Brabant (1).

One fatality involving a woman over 80 in Utrecht with underlying health conditions has been recorded. While approximately 80 percent of infected individuals remain asymptomatic and 19 percent experience flu-like symptoms, about 1 percent develop neurological complications. Vulnerable populations face a higher risk of severe illness.

The virus circulates between mosquitoes and birds. Mosquitoes become infected after biting infected birds and subsequently transmit the virus to humans and horses. While humans and horses can contract the disease, they are not considered infectious to others. The virus was first detected in the Netherlands in 2020, and its presence is linked to mosquito density and weather conditions, posing a risk typically between May and November.