Seasonal surveillance of West Nile Virus infections – 2026 – Monthly report

Findings from human surveillance

EU/EEA countries

In 2026, and as at 4 November, 15 countries in the EU/EEA have reported 1 883 locally acquired [1] human cases of West Nile virus (WNV) infection. The earliest and latest dates of symptom onset among human cases were 22 May in Italy and 18 October in Spain, respectively. Locally acquired cases have been reported by Italy (783 cases), Greece (469 cases, of which 4 had an unknown place of infection), France (191 cases), Spain (149 cases), Romania (125 cases), the Netherlands (76 cases, of which 3 had an unknown place of infection), Croatia (22 cases), Cyprus (21 cases), Belgium (15 cases), Austria (8 cases), Bulgaria (8 cases), Germany (7 cases), Hungary (5 cases), Slovenia (3 cases) and Slovakia (1 case). A total of 148 deaths have been reported by Italy (60 deaths), Greece (53 deaths), the Netherlands (10 deaths), Romania (9 deaths), Spain (7 deaths), France (4 deaths), Belgium (2 deaths), Bulgaria (1 death), Croatia (1 death) and Hungary (1 death).

The number of human cases reported in the EU/EEA so far this year (1 883 cases) is higher than the average number reported during the same period over the past decade (698 cases), and is the highest number of WNV infections in humans ever reported in the EU/EEA.

As at 4 November 2026, locally acquired human cases have been reported in 211 NUTS 3 regions across 15 EU/EEA countries, making this the most geographically widespread WNV season on record.

As in previous years, most cases were reported among males 65 years old and above. Overall, 76% of cases were hospitalised and 56% presented with neurological symptoms, compared with 10-year averages of 84% and 62%, respectively. The case fatality ratio was approximately 8%, below the 10-year average of 10%. These findings are within expected levels and do not indicate increased disease severity compared with previous years. Country-specific case fatality ratios are affected by the sensitivity of the surveillance system, including blood donor screening practices; therefore, direct comparisons between countries should be made with caution.

EU candidate countries

In 2026, and as at 4 November, the following EU candidate countries have reported 146 locally acquired human cases of WNV infection: North Macedonia (71 cases), Serbia (59 cases), Kosovo* (8 cases), Albania (7 cases) and Moldova (1 case). The earliest and latest dates of symptom onset among human cases were 12 May in North Macedonia and 10 October in North Macedonia, respectively. A total of 15 deaths have been reported by North Macedonia (12 deaths), Albania (2 deaths) and Kosovo* (1 death).

Findings from veterinary surveillance

EU/EEA countries

From the veterinary perspective, 13 countries in the EU/EEA have reported 680 WNV outbreaks among equids and 769 outbreaks among birds in 2026.

The earliest reported WNV outbreak among equids had a suspected start date of 30 March 2026 in France, while the most recent had a suspected start date of 27 October 2026 in France. Outbreaks among equids have been reported by France (440 outbreaks), Italy (90 outbreaks), Belgium (45 outbreaks), Spain (26 outbreaks), the Netherlands (24 outbreaks), Germany (15 outbreaks), Greece (14 outbreaks), Portugal (10 outbreaks), Austria (5 outbreaks), Croatia (5 outbreaks), Hungary (4 outbreaks) and Cyprus (2 outbreaks).

Among birds, the earliest reported WNV outbreak had a suspected start date of 31 March 2026 in Italy, while the most recent had a suspected start date of 30 October 2026 in Italy. Outbreaks among birds have been reported by Italy (406 outbreaks), Belgium (274 outbreaks), France (21 outbreaks), Spain (20 outbreaks), Germany (19 outbreaks), Croatia (13 outbreaks), Austria (11 outbreaks), Slovenia (4 outbreaks) and the Netherlands (1 outbreak).

No information was available on the equid species involved in the outbreaks reported in the Animal Disease Information System (ADIS). The bird species most frequently associated with the reported outbreaks were the hooded crow (150 outbreaks), the carrion crow (147 outbreaks) and the common magpie (127 outbreaks), followed by the Eurasian jackdaw (68 outbreaks), the Northern goshawk (37 outbreaks), the common wood-pigeon (30 outbreaks), the Eurasian blackbird (20 outbreaks), the little owl (18 outbreaks) and the common kestrel (17 outbreaks). Several other bird species were also reported, each associated with up to 15 outbreaks.

As at 4 November 2026, the monthly numbers of equid and bird outbreaks reported from July to October were notably higher than their respective historical monthly averages. For equids, monthly outbreak counts ranged from about three times to more than five times the corresponding historical monthly averages for 2016 to 2025. For birds, they ranged from about two times to almost three times the corresponding monthly averages for 2022 to 2025. The cumulative numbers of bird and equid outbreaks reported so far in 2026 were also the highest on record for the same period in any of the preceding years.

So far in 2026, outbreaks in birds and/or equids have been reported in 198 NUTS 3 regions across 13 EU/EEA countries. This exceeds the geographical spread observed during this period in 2025, when outbreaks were reported in 120 NUTS 3 regions across 12 countries, as well as what has been observed in most previous years. The 2026 season was comparable to 2024, which was one of the most geographically widespread WNV seasons for animal outbreaks, with outbreaks in birds and/or equids reported in 200 regions across 14 countries.

Of the 13 EU/EEA countries that submitted data to ADIS in 2026, all had previously reported WNV outbreaks in birds and/or equids, reflecting endemic WNV circulation in these territories.

EU candidate countries and other European countries

In 2026, as at 4 November, one EU candidate country (North Macedonia) and Switzerland had reported WNV outbreaks in birds and/or equids. Switzerland reported one outbreak in equids, with a suspected start date of 21 July. North Macedonia reported four outbreaks in birds, with suspected start dates ranging from 18 August to 7 September.

WNV outbreaks in animals were reported to ADIS for the first time in the NUTS 3 region of Aargau (CH033) in Switzerland and in two regions in North Macedonia: Skopski (MK008) and Pelagoniski (MK005). If the outbreaks reported by EU/EEA countries, EU candidate countries and other European countries are all taken into account, the geographical spread observed to date in 2026 in Europe is slightly greater than what was observed during the same period in 2024.

Patterns across human and veterinary surveillance

EU/EEA countries

Most affected EU/EEA countries reported both human WNV infections and outbreaks in equids and/or birds. Bulgaria, Romania and Slovakia only reported human WNV infections, while Portugal only reported outbreaks among equids.

Differences in WNV patterns across European countries may reflect a combination of ecological, climatic and surveillance-related factors. Climatic conditions, habitat characteristics and the local abundance and distribution of competent mosquito vectors and bird hosts can influence WNV circulation. Differences in surveillance design and intensity, diagnostic practices and reporting may also affect the number of human infections and animal outbreaks detected.

Most human WNV infections are asymptomatic or subclinical. Consequently, the case numbers reported by EU/EEA countries represent only a fraction of the true number of infections. Furthermore, the reported numbers of human cases and animal outbreaks, particularly for October, should be considered provisional, as reporting delays may lead to additional notifications in November or later.

A selection of country-specific findings are presented below to further illustrate the heterogeneity of WNV activity across Europe.

Italy remains the most affected country in 2026, reporting the highest number of human WNV cases (783 cases; 42% of all reported human cases in the EU/EEA), including 60 deaths (case fatality ratio: 8%). Nevertheless, the number of human cases reported was still slightly lower than during the same period in 2025.

Italy also reported the highest number of outbreaks in birds (406 outbreaks; 53% of all avian outbreaks reported in the EU/EEA) and a high number of outbreaks in equids (90 outbreaks; 13% of all equid outbreaks reported in the EU/EEA). As at 4 November, the number of bird outbreaks notified to ADIS was the highest for this period since reporting became mandatory in 2021, while the number of equid outbreaks was higher than in the same period for all previous years except 2018.

Overall, 82 of Italy’s 107 NUTS 3 regions are currently affected, with human WNV cases and/or animal outbreaks reported.

Greece has reported its highest number of human WNV cases (469 cases) to date, including 53 deaths (case fatality ratio: 11%). WNV transmission was most intense in the Attica NUTS 2 region, which accounted for 222 cases. The highest numbers were reported in Anatoliki Attiki (East Attica, 103 cases) and Voreios Tomeas Athinon (North Athens, 64 cases). An additional 79 cases were reported in the Larisa NUTS 3 region. Although Greece represented 25% of all reported human WNV cases in in the EU/EEA, it reported only 14 outbreaks in equids (2% of all equid outbreaks) and no outbreaks in birds.

France has reported 191 locally acquired human WNV infections, including four deaths (case fatality ratio: 3%, among cases with known outcomes), representing 10% of all cases in the EU/EEA. This is by far the highest number of cases ever reported by France. France reported the highest number of equid outbreaks (440 outbreaks), accounting for 65% of the 680 outbreaks reported in the EU/EEA. This was also the highest number of WNV outbreaks in equids ever notified by France. An additional 21 outbreaks were reported in birds.

In the Netherlands, 76 human WNV infections have been reported, including 10 deaths (case fatality ratio: 13%). The Netherlands previously reported locally acquired human WNV infections in 2020, when the country documented its first human cases, with seven cases reported in Utrecht (previously NL310) and one in the Arnhem/Nijmegen region (NL226).

In 2026, 24 outbreaks were reported in equids and one in birds. WNV was first reported in animals in the Netherlands in 2025, with a single equid outbreak. Overall, WNV infections in humans and/or animals were detected across 19 of the 40 NUTS 3 regions in the Netherlands this year.

Belgium has reported 15 human WNV infections, representing the country’s first-ever reported human cases of WNV infection. Two deaths were also reported (case fatality ratio: 15%, among cases with known outcomes).

WNV was first detected in Belgium in 2025 through avian surveillance, with seven bird outbreaks reported in Arr. Mechelen (BE212), Arr. Dendermonde (BE232) and Arr. Halle-Vilvoorde (BE241). In 2026, WNV was again detected in birds in these three regions and spread to 15 additional NUTS 3 regions that had not previously reported WNV activity. Overall, 45 outbreaks in equids and 274 outbreaks in birds were reported across 18 of Belgium’s 44 NUTS 3 regions in 2026.

Other European countries

North Macedonia has reported an unprecedented number of human WNV infections, with 71 cases and 12 deaths (case fatality ratio: 17%), reported from five NUTS 3 regions. Two of these regions have also reported outbreaks among birds. The Skopski region, which includes the capital city of Skopje, is by far the most affected, accounting for 62 human WNV infections and three bird outbreaks. In 2026, North Macedonia reported WNV outbreak data to ADIS for the first time, with four bird outbreaks across two regions. Over the last 10 years, the country reported a maximum of five human WNV infections per year.

More information

The full monthly epidemiological report on human and animal surveillance data including maps and graphs is available at: Monthly updates: 2026 West Nile virus transmission season (europa.eu).

Updated figures on human WNV infections are published weekly at: (Weekly updates: 2026 West Nile virus transmission season (europa.eu).

More background information on the Commission Directives on blood safety and EU/EEA notifications of WNV infections can be found here.

ECDC is monitoring WNV infections through indicator- and event-based surveillance activities.