West Nile Virus

General Information

As in other central and southern European countries, cases of West Nile Virus (WNV) infection in humans and animals have been recorded in various areas of Greece, during the years 2010-2014 and 2017-2018, in almost all Regions (sporadic cases or clusters in the mainland). This suggests that the WNV has been established in our country, as well as in other European countries. As a consequence, the recurrence of WNV infection cases in central and southern Europe (including our country) is considered likely and should be expected in each transmission period, during the mosquito circulation season.

In brief, WNV infection cases, diagnosed and recorded in our country, over the last years (2010-2018), are demonstrated in the following table.

WNV infection cases Year
2010 2011 2012 2013 2014 2015 2016 2017 2018
Total number of cases 262 100 161 86 15 0 0 48 316
Cases with central nervous system  manifestations* 197 75 109 51 14 0 0 28 243
Cases without central nervous system manifestations* 65 25 52 35 1 0 0 20 73
Deaths among cases with WNV disease 35 9 18 11 6 0 0 5 50

*encephalitis and/or meningitis and/or acute flaccid paralysis

During the 2018 season, an early onset of WNV circulation and an increased number of cases was recorded in our country and in other European countries.

Due to its complex epidemiology, WNV’s circulation and geographical distribution during the current 2019 period cannot be safely predicted. As a result, personal protective measures against mosquito bites are encouraged, during the mosquito circulation season, in particular in affected areas (i.e., areas with recording of human cases).

WNV is mainly transmitted through the bite of infected “common” mosquitoes. The main reservoir hosts in the nature are (mainly wild) birds, wherefrom the mosquitoes are infected, while infected humans cannot further transmit the virus and infect other mosquitoes. The majority (80%) of infected humans remain asymptomatic, nearly 20% present mild symptoms of a viral syndrome and less than 1% present severe disease with central nervous systems manifestations, mainly encephalitis, meningitis, or acute flaccid paralysis. The most severe manifestations usually affect the elderly (>50 years old), immunocompromised people and people with chronic underlying diseases.

The epidemiological surveillance of the disease, the timely implementation of appropriate integrated mosquito control programmes and the implementation of personal protection measures against mosquito bites are considered globally the most important measures for the prevention of the disease.

On the N.P.H.O. website you can find information about WNV (informative leaflet “West Nile virus: Learn and Protect”), as well as weekly (and annual) surveillance reports, which include updated information regarding the recording of human WNV cases (if any) and their geographical distribution (affected areas), as well as the public health prevention measures implemented by N.P.H.O.

You can also find a Press Release of N.P.H.O. (21 June 2019) regarding recent WNV media coverage.

Επιδημιολογικά Δεδομένα