Number of Dutch West Nile cases rises to 56
Twelve new infections and four deaths have been reported since the previous update.
There is news on this story (Thursday, 1 October 2026, 14:03): Four patients with West Nile virus have died
Follow-up to: RIVM reports 44 West Nile virus infections in the Netherlands Thursday, 1 October 2026, 11:26
The number of reported Dutch infections with West Nile virus has risen to 56. Since the previous RIVM update, twelve new patients have been registered and four people have died, the institute reports according to ANP.
The new figures mark a clear increase compared with the previous round, in which RIVM reported 44 infections. According to the health authority, all the new patients contracted the virus after being bitten by an infected mosquito. This therefore concerns local transmission via mosquitoes, not person-to-person spread.
West Nile virus circulates between birds and mosquitoes. People and horses can become infected incidentally when bitten by an infected mosquito. According to RIVM, a large proportion of infected people develop no symptoms; a smaller proportion develop flu-like symptoms. Severe neurological disease is much less common.
The four new deaths do not in themselves indicate how serious the outbreak is for the population as a whole. The risk varies according to age and health status, while reported cases depend largely on testing and recognition in healthcare. RIVM therefore publishes data on birds, horses and mosquitoes alongside patient figures.
The European figures are not directly comparable with the Dutch reports. In its 25 September report, ECDC counted 28 locally acquired Dutch cases, while RIVM reported a higher number for the same period. Differences in reporting times, definitions and the completeness of reporting can explain such discrepancies.
The new Dutch figures do show that the virus is present in several locations this season. This update alone does not make it possible to determine definitively whether transmission has now passed its peak. Monitoring will continue as long as there are indications of infected mosquitoes, birds, horses or people.
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The current figures and deaths are attributed to RIVM via ANP. Background claims about transmission and European reporting were checked against RIVM and ECDC.
- confirmed Since the previous update, twelve new Dutch infections have been reported. — Reported by ANP based on RIVM. source
- confirmed Since the previous update, four people have died. — Reported by ANP based on RIVM. source
- confirmed The Dutch cases were contracted via infected mosquitoes. — RIVM describes mosquitoes as the route of transmission. source
- confirmed ECDC reported 28 Dutch cases on 25 September. — Stated in the weekly ECDC report. source
Editor's note
The current figures come from an ANP report citing RIVM. At the time of checking, the public RIVM page was still behind this update; the ECDC figures use a different reporting period and are therefore not directly comparable.Sources
- Vier nieuwe sterfgevallen door besmetting met westnijlvirus — ANP via Welingelichte Kringen
- Actualiteiten over westnijlkoorts — RIVM
- Surveillance of West Nile virus infections in humans in Europe, weekly report — ECDC
The story so far
- Thursday, 1 October 2026, 11:26 RIVM reports 44 West Nile virus infections in the Netherlands
- Thursday, 1 October 2026, 12:02 New deaths from West Nile virus not yet officially confirmed
- Thursday, 1 October 2026, 13:02 Number of Dutch West Nile cases rises to 56 (this article)
- Thursday, 1 October 2026, 14:03 Four patients with West Nile virus have died
More on this in Dutch media
- Het Parool — „westnijlvirus westnijlkoorts”
- Trouw — „westnijlvirus westnijlkoorts”
- NRC — „westnijlvirus westnijlkoorts”