One person in the Arnhem region was infected with the West Nile virus last month, the RIVM reported on Wednesday. It was previously known that six people had contracted the virus in the Utrecht region.
According to the institute, patients in the Utrecht region contracted the infection in the month of July or August. The patient in the Arnhem region became infected in October. According to the RIVM, this is remarkable, because the mosquito season is almost over.
Since Friday 13 November, the Sanquin blood bank has been screening blood donations from the Arnhem region by Sanquin blood bank selectively for the presence of the virus. “This is done to prevent the virus from being transferred to patients in Dutch hospitals via blood transfusion,” says the RIVM.
Via mosquitoes to humans
West Nile virus comes from birds and is transmitted to humans through mosquitoes. Horses can also be infected with it. An infection with the West Nile virus sometimes gives a flu-like illness, according to the RIVM. In rare cases (1 percent) neurological symptoms such as brain inflammation can also occur. People who develop these symptoms run a small risk of death.
First infections in the Netherlands
In October 2020, an infection with the West Nile virus was found for the first time in a patient in the Netherlands. The patient probably contracted the virus in the Utrecht region through a mosquito bite. Birds and mosquitoes with the West Nile virus were found in this region in August and September 2020. It is the first time that an infection with this virus has been found in a person who contracted it in the Netherlands. At the beginning of November, five other infections were found in the Utrecht region and one infection in the Arnhem region.
Complaints of West Nile fever
If you become infected with the virus, it usually takes 3 to 15 days before you can get complaints. Most people (80%) do not get any complaints. About 20% of infected people develop mild flu-like symptoms such as fever, headache and muscle pain. Only a very small proportion (1%) develop a serious illness, such as inflammation of the brain (encephalitis) or inflammation of the brain (meningitis). With these serious illnesses, the chance of death is 4 to 14%. In people aged 70 or older this can increase to 15 to 29%.
How do you get infected?
Infection occurs through infected mosquitoes. This concerns the house mosquito, the most common mosquito species in the Netherlands. The mosquitoes become infected by feeding on infected birds. These mosquitoes then spread the virus to other birds and sometimes to humans and other mammals as well. Under natural conditions, the virus is not transmitted from human to human. But it is possible that someone will be infected by a blood or organ transplant.
How do you prevent contamination?
The most important measure against the virus is to protect yourself from mosquitoes. Especially at dusk, when they are most active. For example, wear covering clothing and / or sleep under a mosquito net.
Where does the West Nile virus occur?
The West Nile virus has spread over many parts of the world in recent decades. The disease has existed for some time in the United States, southeastern Europe and the Mediterranean. In recent years the disease has spread to Central Europe, including the central part of Germany. The first infection in the Netherlands was determined in 2020.
Europe breakout in 2018
A record number of people with West Nile fever were reported in Europe in 2018. There were 2,083 confirmed and suspected patients in one year. That is more than the total number in the previous 7 years (1,832 reported cases in total). The cause of this outbreak is probably due to the combination of very high temperatures and the presence of many mosquitoes and birds.