Europe - Update: West Nile virus, cases exceed total in previous 5 years
According to a news release by the European Centre for Disease Prevention and Control (ECDC) on 24 September 2018, since the last epidemiological update on 31 August 2018, European countries have reported 530 new West Nile virus (WNV) cases and 52 deaths. The number of West Nile Virus infections reported so far exceeds the total number of infections in the previous five years.
In 2018, as of 20 September 2018, 1 505 confirmed and probable locally acquired human WNV infections were reported by European countries. EU/EEA Member States reported 1 135 human cases in Italy (453), Greece (225), Romania (216), Hungary (167), Croatia (36), France (16), Austria (15), Bulgaria (4) and Slovenia (3). EU neighbouring countries reported 370 human cases in Serbia (286), Israel (81) and Kosovo** (3). To date, 115 deaths due to West Nile virus infection have been reported by Italy (35), Serbia (29), Romania (25), Greece (24), Hungary (1) and Kosovo** (1).
The case fatality ratio (CFR) in 2018 has not exceeded the CFR in the previous two years (7.6% in 2018 compared with 11.1% in both 2016 and 2017). The proportion of cases with West Nile neuroinvasive disease (WNND) among symptomatic cases is lower than the previous two years (70% in 2018 compared with 82% in 2017 and 86% in 2016).
All human cases reported during the current transmission season were in previously affected countries. The assessment of the transmission risk in the EU/EEA as stated in ECDC’s rapid risk assessment published on 13 August 2018 remains valid. Personal protection from mosquito bites is advisable for any person residing in or visiting affected areas, especially the elderly and immunocompromised who are at higher risk of developing severe symptoms.
Figure 1. Number of West Nile fever cases in EU/EEA and EU enlargement countries by epidemiological week of notification, 2014 to 2018, as of 20 September 2018
*Week of notification to national authorities or if missing, week of notification to ECDC.
ECDC update on 28 September 2018
Between 21 and 27 September 2018, EU Member States reported 132 human West Nile virus infections: Greece (37), Italy (42), Hungary (23), Romania (21), Croatia (8) and Bulgaria (1). The EU neighbouring countries reported 34 cases, all by Serbia.
In four areas, human cases were reported for the first time: Croatia (2), Bulgaria (1) and Serbia (1). All other human cases were reported from areas that have been affected during previous transmission seasons.
Within the week, 9 deaths were reported by Romania (5), Greece (2), Bulgaria (1) and Italy (1).
In 2018, as of 27 September 2018, EU Member States have reported 1 266 human cases: Italy (495), Greece (261), Romania (237), Hungary (190), Croatia (44), France (16), Austria (15), Bulgaria (5) and Slovenia (3). EU neighbouring countries reported 404 human cases: Serbia (320), Israel (81) and Kosovo* (3). To date, 124 deaths due to West Nile virus infection have been reported by Italy (36), Romania (30), Serbia (29), Greece (26), Bulgaria (1), Hungary (1) and Kosovo** (1).
The map below by ECDC shows the distribution of human West Nile virus infections in the region, as of 27 September 2018.
[Note from ECDC: **This designation is without prejudice to positions on status, and is in line with UNSCR 1244 and the International Court of Justice Opinion on the Kosovo Declaration of Independence.]