Epidemiological summary

Since the beginning of 2024, and as of 2 October 2024, 18 countries in Europe reported human cases of West Nile virus infection: Albania, Austria, Bulgaria, Croatia, Czechia, France, Germany, Greece, Hungary, Italy, Kosovo*, North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain and Türkiye.

Please note: The table and map in this report contain countries and areas where human West Nile virus infection cases were reported to The European Surveillance System (TESSy).

Introduction

According to the Commission Directives 2004/33/EC and 2014/110/EU on blood safety, blood establishments in the EU/EEA, countries should apply temporary deferral criteria for donors of allogeneic blood donation for 28 days after leaving a risk area of locally acquired1 West Nile virus (WNV) unless an individual Nucleic Acid Test (NAT) is negative.

The WNV surveillance activities carried out by ECDC support the competent authorities responsible for blood safety in the implementation of these directives. Therefore, the Emerging and Vector-borne Diseases team at ECDC currently provides weekly and monthly updates with the latest reports on cases of WNV infections in Europe2. A map and table are updated every Friday from June to November which is the time of the year WNV infections are most likely to be reported. In addition, an interactive dashboard is made available. ECDC provides an enhanced analysis of the current WNV epidemiology on a monthly basis, which includes an assessment of the situation.

Here we present the weekly report as of 2 October 2024.

EU/EEA notification of West Nile virus infections

West Nile virus infection in humans is a notifiable disease at the EU level and cases should be reported by national public health authorities through the European Surveillance System (TESSy) according to the EU case definition.

Outbreaks of WNV infections in equids and birds should be notified to the Animal Disease Information System (ADIS) of the European Commission. At the EU/EEA level it is mandatory to report equine encephalomyelitis due to WNV infection and West Nile virus infections among birds in accordance with Commission Implementing Regulation (EU) 2018/1882. Data from passive and active surveillance activities including outbreaks are collected by the European Food Safety Authority (EFSA). Analyses of animal data are only included in the monthly update.

Overview of West Nile virus cases in EU/EEA and EU-neighbouring countries

Table 1.- Countries and regions with locally acquired human cases of West Nile virus infections in 2024 till 2 October 2024.

Geographical distribution

Figure 1.- Distribution of locally acquired human West Nile virus infections in 2024 till 2 October 2024.