West Nile virus in the Netherlands

16 Sep 2020 | Back to News, Publications and Annual Reports



Experts had long suspected, but now we know for sure. The West Nile virus has reached the Netherlands. The National Institute for Public Health and the Environment reports that a warbler has been found carrying the West Nile virus in the Utrecht region.

Like Covid-19, it is a zoonosis. In this case, a bird virus that can spread to some mammals, including horses and humans. Unlike covid-19, the West Nile virus does not spread through small cough or sneeze droplets but through mosquitoes.

Dutch average summers

The West Nile virus is particularly notorious for its rapid spread. When it reached the United States via the New York harbor in 1999, it spread across both North and South America within a decade. The virus is also emerging in Europe. It is getting closer from the south and east. Researchers from Wageningen have previously shown that Dutch mosquitoes can transmit the West Nile virus, but that the temperature of the typical Dutch summers was an important limiting factor. The long period of warm weather may have played a role last month.

West Nile fever

We don't have to worry right now, because usually a West Nile virus infection happens unnoticed. About one in five people has mild symptoms similar to the flu. This is called West Nile fever. In exceptional cases, the virus can enter the brain and the patient develops neurological complaints.

No medicine

There is as yet no medicine or treatment for West Nile fever or for the neurological complaints caused by the West Nile virus. There is a vaccine for horses, a vaccine for humans is being developed.

Read more about our West Nile virus vaccine research here.

Photo: No-longer-here via Pixabay