Seasonal surveillance of West Nile Virus infections – 2026 (weekly report)

Since the beginning of the 2026 transmission season, and as at 7 October, 208 areas affected by West Nile virus (WNV) have been identified in 18 countries across Europe.

These areas are located in Italy (67), France (26), Greece (25), Romania (24), the Netherlands (15), Serbia (10), Belgium (6), Spain (6), Croatia (5), North Macedonia (5), Hungary (4), Kosovo* (4), Austria (3), Germany (3), Albania (2), Bulgaria (2) and Cyprus (1).

The 18 countries have reported 1 855 locally acquired human cases of WNV infection.

This week, six areas are reported as affected for the first time this season.

The report will be made available online on Friday afternoon 9 October at the following link: link.

Throughout the season, ECDC will publish a weekly report with updates on risk areas for locally acquired WNV infections. A monthly report is also published.

WNV infection in humans is a notifiable disease at the EU level and cases should be reported by national public health authorities through the EpiPulse Cases platform in accordance with the EU case definition. According to Commission Directives 2004/33/EC and 2014/110/EU on blood safety, blood establishments in European Union/European Economic Area (EU/EEA) countries should apply temporary deferral criteria for donors of allogeneic blood donation for 28 days after they have left a risk area for locally acquired WNV, unless an individual nucleic acid test (NAT) is negative. WNV surveillance activities carried out by ECDC support the competent authorities responsible for blood safety in the implementation of these directives.

* This designation is without prejudice to positions on status and is in line with UNSCR 1244/1999 and the ICJ Opinion on the Kosovo declaration of independence.

ECDC will provide weekly and monthly updates with the latest reports on cases of WNV infections in Europe. A map and table will be updated every Friday from now until November, as this is the time of year when WNV infections are most likely to be reported.

ECDC will provide an enhanced analysis of the current WNV epidemiology on a monthly basis together with the European Food Safety Authority (EFSA), which includes information on the number of locally acquired human cases reported, outbreaks of West Nile fever in equids and birds notified to the Animal Disease Information System (ADIS) of the European Commission, and an assessment of the situation.