Warning after Dutch blood donor infected with West Nile virus

A case of West Nile virus has been detected in a Dutch blood donor in the first infection of its kind for six years.

The donor, who lives in Utrecht province, is though to have contracted the virus in the Netherlands, as they have not been abroad recently, the public health agency RIVM said.

The virus was confirmed after the patient reported mild symptoms of West Nile fever. Blood bank Sanquin subsequently carried out laboratory tests on a number of samples.

Some 80% of people who contract the virus have no symptoms, but around 1% develop neurological problems, mainly people over 50 with weakened immune systems. In rare cases it can be fatal.

The disease mainly occurs in birds, but can be transmitted to other species, including humans, by mosquitoes. There are no known cases of transmission between humans.

Horse and bird infected

The RIVM said the virus had also been detected in a horse and a bird in different locations in the Netherlands, indicating that mosquitoes that carry the virus are active in the country.

The agency advised people to wear clothes with long sleeves, apply mosquito repellent and use screens or mosquito nets to keep the insects out. It added that the risk of contracting West Nile virus in the Netherlands was small.