RIVM: Netherlands records 72 West Nile virus cases
- The Netherlands has recorded 72 total cases of the West Nile virus this year after eight new infections were confirmed last week, according to data released on October...
- Geographic distribution data shows that Zuid-Holland remains the most heavily affected area in the country with 41 documented infections.
- Concurrent testing among animals revealed 32 birds and five horses testing positive for the virus during the mid-October reporting window.
The Netherlands has recorded 72 total cases of the West Nile virus this year after eight new infections were confirmed last week, according to data released on October 22, 2026, by the Rijksinstituut voor Volksgezondheid en Milieu (RIVM). While seasonal transmission has slowed, the total marks an increase from the 64 cases reported by the public health institute one week prior. Ten people have died in the Netherlands following infection with the virus, a fatality figure that has remained unchanged across recent weekly updates.
Regional spread across Dutch provinces
Geographic distribution data shows that Zuid-Holland remains the most heavily affected area in the country with 41 documented infections. Infections have also been confirmed across Utrecht, Noord-Holland, Noord-Brabant, Gelderland, and Overijssel. In Noord-Brabant specifically, seven people have contracted the virus this year.
Concurrent testing among animals revealed 32 birds and five horses testing positive for the virus during the mid-October reporting window. Across the border, the Vlaamse Departement Zorg announced that in Flanders two people have died among twelve recorded infections, marking the first fatalities from the virus in that region.
Seasonal decline in mosquito activity
The recent slowdown in new infections is directly tied to weather patterns and seasonal shifts. The RIVM stated that the passing of the peak mosquito season, combined with lower ambient temperatures that reduce viral activity in vectors, explains the drop in new human cases compared to the summer months. Mosquitoes acquire the pathogen by feeding on infected birds before transmitting it to humans and other animals.
European health monitoring indicates a broader continental trend. The European Centre for Disease Prevention and Control (ECDC) reported 1,715 West Nile virus infections across the European Union this year, representing the highest annual total on record. Italy accounts for the largest share with 748 cases, alongside significant numbers in Greece and France. The ECDC noted that the appearance of the virus in the Netherlands and Belgium demonstrates that the pathogen is expanding further north.
Clinical severity and vulnerable populations
Despite the rising continental case counts, public health officials emphasize that the overall risk of contracting the virus in the Netherlands remains low. Approximately 80 percent of infected individuals experience no symptoms at all, while roughly 19 percent develop flu-like symptoms. Only about one percent of those infected develop neurological symptoms, such as brain inflammation, meningitis, or a form of polio.
Data from public health authorities indicates that individuals with underlying health conditions or advanced age face the highest risk of severe illness or death. All ten individuals who died in the Netherlands following infection were on age or had an underlying condition. Furthermore, the ECDC noted that the proportion of patients requiring hospitalization or dying after infection is relatively lower than in previous decades, though the agency has not yet identified a specific driver for this shift.
Anticipating future transmission patterns
Public health authorities continue to monitor vector populations and migratory bird routes as colder autumn conditions take hold across Western Europe. The ECDC projects that viral transmission into northern regions will likely persist in coming years.
