Two more deaths linked to West Nile virus in the Netherlands; Infections double to 18
Two more people in the Netherlands have died as a result of symptoms caused by a West Nile virus infection according to Dutch public health institute RIVM. Three people have died this year from the disease, the RIVM said on Thursday. A total of 18 cases of West Nile have been diagnosed in the country this year, twice the total the institute confirmed last week, and infections are spreading among horses and birds, with crows showing a high rate of death.
The Netherlands had one confirmed fatal case of West Nile virus, and nine infections, as of last Thursday. The first individual who died this year was confirmed towards the end of August. Not a single person was confirmed to have the infection in all of 2025.
Of the 18 cases this year, one was discovered when Sanquin Research screened a blood donation. "In the other individuals, West Nile virus was diagnosed after they were admitted to the hospital with symptoms."
There infections arose in six total provinces, the RIVM stated in its update. "The patients contracted West Nile virus after being bitten by an infected mosquito in the provinces of Utrecht, Noord-Brabant, Noord-Holland, Zuid-Holland, Overijssel, and Gelderland," the RIVM confirmed, with the two latter regions being mentioned for the first time in the current outbreak.
A woman from Drenthe likely died from West Nile fever last month after becoming infected while abroad. The public health office in the region, GGD Drenthe, said she contracted the virus while traveling through southeastern Europe. Her symptoms first emerged while she was still abroad.
One of the individuals infected is a 39-year-old Amstelveen woman, AT5 reported. The local broadcaster said she was infected in the Netherlands, and it was discovered after she developed meningitis.
Researchers have now found three mosquito pools in the Netherlands where the virus is circulating, up from two at the start of September. That matches the same total as last year, though no human infections were reported in 2025.
West Nile virus was first found in someone in the Netherlands nearly six years ago. It was first observed in the country a few weeks earlier during the summer of 2020.
Around 20 percent of people infected with West Nile virus begin to show mild symptoms similar to the flu, the RIVM said. Common symptoms include fever, headache, upset stomach, muscle aches, stomach pain, and diarrhea. It can also cause swollen lymph nodes, or a rash.
More serious symptoms present in about 1 percent of patients infected with the virus. This includes encephalitis and meningitis. When serious symptoms develop, survival rate ranges from 86 to 96 percent. However, the risk of death in people over 70 years of age can be twice as likely.
The West Nile virus is also spreading among horses and birds, according to researchers. "Since the previous update on September 3, the NVWA has received 53 reports of horses with West Nile virus. This brings the total number of reports in 2026 to 58 horses."
A joint research group also found that "23 dead and 10 living wild birds tested positive for West Nile virus last week. Up to and including September 2, 2026, there were six birds with West Nile virus. In total, 39 birds with West Nile virus have now been reported in 2026."
The RIVM said that there was a strikingly high morbidity rate among birds in the Corvid family, such as various crows. Birds native to the Netherlands in this group include the black carrion crow, the Eurasian magpie, rooks, the Eurasian Jay, and the common raven.