Epidemiological summary

As of 24 June, two countries in Europe reported three locally acquired1 human cases of WNV infection: Italy reported two cases and North Macedonia one case. Dates of onset ranged from 12 to 27 May 2026. No deaths have been reported.

The cases were reported from three regions across the two countries. Although no cases had been reported by this time in 2025, some cases with onset dates in May and June were subsequently notified with a delay. Therefore, the current situation remains consistent with the early phase of the seasonal reporting pattern observed in previous years.

This year, human cases of WNV infection were reported for the first time ever in one affected area: North Macedonia in Vardarski (MK001).

Among the three cases reported this year, one person was aged 65 years or older, one was aged under 65 years, and the age of one person was unknown. All three cases were hospitalised. Neurological manifestations were reported in two individuals; information on clinical presentation was unavailable for the remaining case. As only three cases have been reported to date, comparisons with demographic or severity patterns observed over the previous decade are not yet meaningful. Further updates will be provided in subsequent monthly reports.

From the veterinary perspective, five WNV outbreaks have been reported in Europe in 2026: one among equids and four among birds. The equid outbreak was reported by France and started on 30 March 2026. The four bird outbreaks were reported by Italy, with start dates ranging from 31 March to 4 May 2026.

No information was available on the equid species involved in the outbreak reported in France in the Animal Disease Information System (ADIS). For birds, species information indicated that the four outbreaks reported in Italy involved hooded crows (three outbreaks) and a golden eagle (one outbreak).

Outbreaks in birds and/or equids have been reported in three regions across two countries. Both countries that reported outbreaks in 2026 had previously reported WNV outbreaks in birds and/or equids in the same regions, indicating that WNV is endemic in these areas.

The number of outbreaks in birds and equids reported during this first period of 2026 is similar to the mean monthly outbreak count for the same time of year, calculated for 2022–2025 for birds and for 2016–2025 for equids.

Italy reported both locally acquired human WNV cases and WNV outbreaks in birds; however, the human cases and bird outbreaks were reported from different regions.

Owing to delays in diagnosis and reporting, and because most WNV infections are asymptomatic or subclinical, the reported case numbers likely underestimate the true number of infections. Seasonal surveillance in humans primarily captures laboratory-confirmed cases, which may further contribute to reporting delays.

Given the favourable weather conditions for WNV transmission in Europe, ECDC and EFSA expect further human cases and outbreaks in equids and birds to be reported in the coming weeks and months. In previous years, transmission has typically peaked in August and September.

ECDC and EFSA will continue to closely monitor the situation in Europe.

Introduction

In the context of their ‘One Health’ activities, the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA) conduct joint surveillance of West Nile virus (WNV) infections in humans, equids, and birds, while also assessing the epidemiological situation in Europe. This initiative aims to inform public health and veterinary authorities in Europe, facilitating the implementation of prevention and control measures. These measures include the deferral or testing of blood donors who have potentially been exposed to the virus, in accordance with Commission Directives Commission Directives 2004/33/EC and 2014/110/EU.

The tables and maps in this monthly report show the countries and areas where human cases of WNV infection and outbreaks among equids and birds have been reported to the European surveillance portal for infectious diseases (EpiPulse Cases) and the Animal Disease Information System (ADIS). In addition to this monthly report, ECDC provides a weekly report presenting the locally acquired WNV infections among humans in Europe2.

For the analysis of ADIS outbreak data, this report includes only animal outbreaks with a ‘suspicion/start date’ in 2026. For analysis of historical data, when the ‘suspicion/start date’ was not reported, the ‘confirmation date’ was used instead. Outbreaks of WNV in animals shall be notified to ADIS in accordance with the indications and definitions laid down in Commission Implementing Regulation (EU) 2020/2002. A notified outbreak may include one or more WNV cases. Since there is no specific case definition for WNV infection in animals, the general definition provided in Article 9 of Commission Delegated Regulation (EU) 2020/689 applies. When comparing the number of WNV outbreaks in birds reported in 2026 with historical data, a four-year average (2022–2025) was used – rather than the 10-year average applied to equids – since mandatory reporting of WNV outbreaks in birds only began in April 2021.

Overview of WNV cases in Europe

Table 1. Number of locally acquired human cases of WNV infections and number of WNV outbreaks among equids and birds reported within Europe in 2026 by reporting country and region of infection (NUTS 3 or GAUL 1 level), as of 24 June 2026 .

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

Epicurves

Human cases

Overall (weekly)

Figure 1. Number of locally acquired human cases of WNV infections reported within Europe in 2026, by week and as of 24 June 2026.

By country (weekly)

Figure 2. Number of locally acquired human cases of WNV infections reported within Europe in 2026, by country and as of 24 June 2026.