Epidemiological summary

In 2024, and as of 4 December 2024, 19 countries in Europe have reported 1436 locally acquired1 human cases of WNV infection with known place of infection. The earliest and latest date of onset were respectively on 1 March 2024 and 25 October 2024. Locally acquired cases were reported by Italy (455), Greece (217), Spain (138), Hungary (111), Albania (106), Romania (99), Türkiye (90), Serbia (63), France (39), Austria (34), Germany (27), Croatia (20), Bulgaria (16), Slovakia (6), Slovenia (5), Kosovo* (4), Cyprus (2), Czechia (2) and North Macedonia (2). In Europe, 125 deaths were reported by Greece (34), Italy (21), Romania (20), Spain (15), Albania (13), Türkiye (7), Hungary (5), Serbia (5), Bulgaria (3), France (1) and North Macedonia (1).

Case numbers reported this year are above the mean monthly case count for the past 10 years. During the same period in 2023, 802 cases were reported. However, numbers are lower than in 2018, when 2 115 cases had been reported by this time of year.

All 19 countries had reported human cases of WNV infections in the past. However, Albania, Czechia, Kosovo*, Slovenia and Türkiye have not reported any human cases in the past four to five years. In Albania, the outbreak in 2024 was the largest outbreak of WNV infections among humans ever detected in the country.

In addition, Poland reported its first locally acquired human case of WNV infection. This case was classified as a probable case. However, as information on the place of infection within the country was not reported to ECDC, this case was not included in the case count above.

In 2024, 212 regions across 19 countries have reported locally acquired human cases of WNV infection this year, compared to 137 regions in 2023 and 173 regions in 2018 during the same period. This is the largest geographical distribution of WNV ever reported in a year. The following regions have reported locally acquired human cases of WNV infection for the first time ever: Berat, Elbasan, Kavaje, Kucove, Kurbin, Lushnje, Vlore, Mallakaster, Kruje and Pogradec in Albania, Kardzhali in Bulgaria, Bjelovarsko-bilogorska županija in Croatia, Gard, Hérault, Pyrénées-Atlantiques and Guadeloupe in France, Diepholz, Oder-Spree, Jena Kreisfreie Stadt, Dithmarschen, Segeberg, Havelland, Jerichower Land, Börde and Bautzen in Germany, Thesprotia in Greece, Barletta-Andria-Trani, Benevento, Chieti, Roma, Firenze, Napoli and Caserta in Italy, Prishtinë, Prizren and Mitrovicë in Kosovo*, Pološki in North Macedonia, Trnavský kraj and Nitriansky kraj in Slovakia, Podravska in Slovenia, Málaga and Jaén in Spain, Edirne, Bursa, Osmaniye and Kirklareli and Tekirdag in Türkiye.

As observed in previous years, most cases are among men aged over 65 years. Severity indicators are comparable to those observed in previous years, with 91% of cases hospitalised, a case fatality rate of 9% and neurological manifestations in 68% of the cases. The dominance of neurological cases is expected, as cases with more severe symptoms are more likely to be diagnosed.

In addition, travel-associated cases from outside of the EU/EEA have been reported in travellers arriving from Albania, Angola, Bosnia and Herzegovina, Egypt, India, Kenya, Morocco, Oman, Tunisia, Türkiye, Uganda, the United Arab Emirates and the United States.

From the veterinary perspective, 494 WNV outbreaks among equids and 447 outbreaks among birds have been reported in Europe in 2024. Outbreaks among equids have been reported by Germany (177), France (83), Spain (68), Austria (55), Hungary (41), Italy (36), Portugal (17), Croatia (8), Poland (6) and Greece (3). Outbreaks among birds have been reported by Italy (312), Germany (80), Austria (20), Spain (14), Slovenia (6), France (5), Hungary (3), Bulgaria (2), Croatia (2), Poland (2) and Latvia (1). The earliest and latest date of start of an outbreak among birds and/or equids were respectively on 2 April 2024 and 25 November 2024.

Due to the delay in diagnosis and reporting of cases of WNV infection, and that a majority of the WNV infections remain asymptomatic or pauci-symptomatic, the case numbers provided in this report are not a true representation of the actual number of cases. As in previous years, the peak of transmission was observed in August−September. As environmental conditions are no longer favourable for vector activity and virus replication in vectors, no more locally acquired WNV infections are expected in 2024.

This report is the last monthly report for 2024. The next monthly report is expected to be published upon occurrence of the first human cases in 2025, expected in June/July.

Introduction

ECDC is conducting enhanced surveillance of West Nile virus (WNV) infections among humans, equids, and birds to assess the situation and inform public health and veterinary authorities in Europe about the current epidemiological status. This surveillance supports the competent authorities responsible for blood safety in implementing Commission Directives 2004/33/EC and 2014/110/EU, ensuring blood safety in the European Union.

The tables and maps in this report contain countries and areas where human cases of WNV infection and outbreaks among equids and birds were reported to The European Surveillance System (TESSy) and the Animal Disease Information System (ADIS), respectively.

ECDC provides a weekly report mapping the locally acquired WNV infections among humans in Europe2.

In addition, this monthly report provides a description of the epidemiological situation in humans, bird and equids in Europe.

Here we present the monthly report as of 4 December 2024.

Overview of WNV cases in Europe

Table 1. Number of locally acquired human cases of WNV infections reported within Europe in 2024 by reporting country and region of infection (NUTS 3 or GAUL 1 level), as of 4 December 2024.

When importing data.csv in MS Excel, please do not forget to select Unicode (UTF-8) as encoding.

Epicurves

Overall (weekly)

Figure 1. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by week and as of 4 December 2024.

By country (weekly)

Figure 2. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by country and as of 4 December 2024.

Overall (monthly)

Figure 3. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by month , and during the previous 10 years, as of 4 December 2024.

By country (monthly)

Figure 4. Distribution of locally acquired human cases of WNV infections reported within Europe in 2024, and during the previous 10 years, as of 4 December 2024.

Maps

Cases in human - Current year

Figure 5. Spatial distribution of locally acquired human cases of WNV infections within Europe in 2024 by NUTS3 or GAUL 1 regions, as of 4 December 2024.

Outbreaks in equids and/or birds - Current year

Figure 6. Spatial distribution of WNV outbreaks among equids and/or birds in NUTS 3 regions in the EU/EEA during 2024, as of 4 December 2024.

One Health aggregated distribution

Figure 7. Distribution of locally acquired human WNV infections in NUTS 3 or GAUL 1 regions among equids and/or birds within Europe during 2024, as of 4 December 2024.

Human cases - Historical

Figure 8. Spatial distribution of locally acquired human cases of WNV infections in NUTS3 or GAUL 1 regions within Europe during 2024, and during the last 10 years, as of 4 December 2024.

Demographics

Overall (Age and gender)

Figure 9. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by age group and gender, as of 4 December 2024.

Age by country

Figure 10. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by age group and reporting country, as of 4 December 2024.

Gender by country

Figure 11. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by gender and reporting country, as of 4 December 2024.

Severity

Outcome

Overall

Figure 12. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by outcome, as of 4 December 2024.

By country

Figure 13. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by outcome and reporting country, as of 4 December 2024.

Hospitalisation

Overall

Figure 14. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by hospitalisation status, as of 4 December 2024.

By country

Figure 15 . Number of locally acquired human cases of WNV infections reported within Europe in 2024, by hospitalisation status and reporting country, as of 4 December 2024.

Clinical manifestations

Overall

Figure 16. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by clinical manifestations, as of 4 December 2024.

By country

Figure 17. Number of locally acquired human cases of WNV infections reported within Europe in 2024, by clinical manifestations and reporting country, as of 4 December 2024.

Outbreaks among equids and birds

Equids - Current season

Figure 18. Number of WNV outbreaks among equids reported in the EA/EEA in 2024, by week and as of 4 December 2024.

Birds - Current season

Figure 19. Number of WNV outbreaks in birds reported within Europe in 2024, by week and as of 4 December 2024.

Equids and/or birds - Current and Historical

Figure 20. Number of WNV outbreaks among equids and/or birds reported within Europe in 2024 and during the previous 10 years, by month as of 4 December 2024.

Download the data

Download the dataset for West Nile virus surveillance. When importing data.csv in MS Excel, please do not forget to select Unicode (UTF-8) as encoding.


  1. Locally acquired cases refer to cases acquired within the reporting country.↩︎

  2. In this report, Europe refers to EU/EEA countries and EU-neighbouring countries (Albania, Bosnia and Herzegovina, Kosovo*, Montenegro, North Macedonia, Serbia and Türkiye).

    *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.

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