Historical data by year - West Nile virus seasonal surveillance

West Nile virus infections in 2022

As of 31 May 2023, European Union, European Economic Area and EU-neighbouring countries have reported 1 339 locally acquired human cases of West Nile virus infection, including 104 deaths, in 2022. This is the highest reported number of locally acquired cases since the peak epidemic year 2018. 

European Union (EU) and European Economic Area (EEA) countries have reported 1 133 human cases of West Nile virus (WNV) infection through The European Surveillance System (TESSy), including 92 deaths for 2022, of which 1 112 were locally acquired, 17 were travel-related, and four had an unknown place of infection.   

Ten EU/EEA countries reported 1 106 locally acquired human cases of WNV infection with known place of infection at NUTS3 level. Locally acquired cases were reported by Italy (723), Greece (283), Romania (47), Germany (16), Hungary (14), Croatia (8), Austria (6), France (6), Spain (4), and Slovakia (1).

West Nile virus infections in 2021

As of 10 February 2022, European Union (EU) and European Economic Area (EEA) countries and EU-neighbouring countries reported 164 human cases of West Nile virus (WNV) infections in 2021, of which 159 were locally acquired and five were travel-related.

EU/EEA countries reported 139 human locally acquired cases of WNV infection with known place of infection, including 10 deaths, through The European Surveillance System (TESSy). Cases were reported by Greece (57), Italy (55), Hungary (7), Romania (7), Spain (6), Germany (4) and Austria (3). Additionally, two locally acquired cases were reported with unknown place of infection on NUTS3 level by Greece. Deaths were reported by Greece (8), Romania (1) and Spain (1).

West Nile virus infections in 2020

As of 1 February 2021, European Union (EU) and European Economic Area (EEA) Member States and EU-neighbouring countries reported 336 locally-acquired human cases of West Nile virus (WNV) infections in 2020. EU/EEA Member States reported 316 locally-acquired human cases of WNV infection with known place of infection, including 38 deaths, through The European Surveillance System (TESSy). Cases were reported by Greece (143), Spain (77), Italy (66), Germany (13), the Netherlands (7), Romania (6), Hungary (3) and Bulgaria (1). Deaths were reported by Greece (23), Spain (8), Italy (5), Romania (1) and Bulgaria (1).

West Nile virus infections in 2019

As of 4 December 2019, European Union (EU) Member States and EU neighbouring countries reported 463 human infections in 2019. EU Member States reported 410 cases: 223 in Greece, 66 in Romania, 53 in Italy, 36 in Hungary, 16 in Cyprus, 5 in Bulgaria, 4 in Austria, 4 in Germany, 2 in France and 1 in Slovakia. EU neighbouring countries reported 53 human cases: 27 in Serbia, 10 in Israel, 10 in Turkey and 6 in North Macedonia. In the same time period, 50 deaths due to West Nile virus infections have been reported.

West Nile Fever data, 2018

In the 2018 transmission season a higher number of cases were reported compared with transmission seasons in previous years. The total number of reported autochthonous infections in 2018 (n= 2 083) exceeds, by far, the total number from the previous seven years (n= 1 832).Compared to the previous transmission season in 2017, there was a 7.2-fold increase. The highest increase compared to the previous transmission season was observed in Bulgaria (15-fold) followed by France (13.5-fold) and Italy (10.9).

West Nile fever data 2017

In 2017, for the first time, ECDC included equine West Nile fever cases in its epidemiological updates. During the 2017 transmission season, 204 human cases and 127 equine cases were reported in the European Union.

West Nile fever data 2016

In 2016, 225 human cases of West Nile fever have been reported in the EU: most cases were reported in Romania and Italy. Hungary and Romania reported a significant increase in number of cases compared to the previous season. Cyprus saw its first human case of West Nile fever. Both Russia and Israel reported a large number of cases.

West Nile fever data 2015

Since the 5 June 2015, ECDC has published on its website an interactive atlas presenting weekly updates on spatial distribution of West Nile fever human cases in the European Union and neighbouring countries. In the EU, reported cases are neuro-invasive and non neuro-invasive autochthonous West Nile fever cases meeting laboratory criteria as per the EU case definition (Directive 2008/426/EC). Outside the EU, all non-imported cases are included.   The first case of West Nile fever was reported on 23 June 2015 from Sofia in Bulgaria. Since the beginning of the 2015 transmission season, 108 cases of West Nile fever in humans have been reported in the EU, 60 in Italy, 18 in Hungary, 19 in Romania, seven in Austria, two in Bulgaria, one in France and one in Portugal. In neighbouring countries, 193 cases have been detected in Israel (125), the Russian Federation (39), Serbia (28) and Palestine* (1). 

West Nile fever data 2014

The figures for the 2014 season are as follows: 74 autochthonous cases were detected in the EU and 136 cases in neighbouring countries. In the EU, cases were reported from the following countries: Austria (1), Greece (15), Hungary (11), Italy (24) and Romania (23). In neighbouring countries, cases were reported in Bosnia and Herzegovina, Israel, Palestine*, the Russian Federation and Serbia.

*This designation shall not be construed as recognition of a State of Palestine and is without prejudice to the individual positions of the Member States on this issue.

West Nile fever data 2013

In 2013, ECDC monitored the West Nile fever situation during the transmission season (June to November) in the EU Member States and neighbouring countries. The figures for the 2013 season are the following: 228 autochthonous cases were detected in the EU and 557 in neighbouring countries. In the EU, the cases reported from the following countries: Greece (86), Italy (69), Hungary (31), Romania (24), Croatia (16), Czech Republic (1) and Slovenia (1). In the neighbouring countries, cases have been notified in Bosnia and Herzegovina, Former Yugoslav Republic of Macedonia, Israel, Montenegro, Russian Federation, Serbia, Tunisia and Ukraine. For a more detailed overview, including the regional level, please see the West Nile map for 2013.  

West Nile fever data 2012

In 2012, ECDC monitored the West Nile fever situation during the transmission season (June to November) in the EU Member States and neighbouring countries. The figures for the 2012 season are the following: 242 autochthonous cases were detected in the EU and 693 in neighbouring countries. The cases reported in the EU included 161 cases from Greece, 50 from Italy (including five asymptomatic blood donors), 17 from Hungary and 14 from Romania. In the neighbouring countries, cases have been notified in Algeria, Croatia, Former Yugoslav Republic of Macedonia, Israel, Kosovo*, Montenegro, Occupied Palestinian territory, Russian Federation, Serbia, Tunisia and Ukraine. For a more detailed overview, including the regional level, please see the West Nile map for 2012.

* This designation is without prejudice to positions on status, and is in line with UNSCR 1244 and the IСJ Opinion on the Kosovo Declaration of Independence

West Nile fever data 2011

In 2011, ECDC monitored the West Nile fever situation during the transmission season (June to November) in the EU Member States and neighbouring countries. The figures for the 2011 season are the following: 128 autochthonous cases were detected in the EU and 212 in neighbouring countries. The cases reported in the EU included 100 cases from Greece, 14 from Italy, 11 from Romania and three from Hungary. In the neighbouring countries, cases have been notified in Albania, Former Yugoslav Republic of Macedonia, Israel, Russian Federation, Tunisia, Turkey and Ukraine. For a more detailed overview, including the regional level, please see the West Nile map for 2011.

West Nile fever data 2010

In 2010, autochthonous human cases of West Nile fever were detected in several EU countries: Austria, Greece, Hungary, Italy, Romania and Spain. In Greece, a large outbreak affected the northern part of the country, Central Macedonia, with 262 human cases and 35 deaths reported. At the same time, outbreaks of West Nile fever were also reported from Turkey and Russia.