The Greece National Public Health Organization (EODY) informs that the first cases of West Nile virus (WNV) infection for the 2025 transmission period have been diagnosed in our country.
Specifically, four cases of infection were diagnosed - simultaneously, in the last 48 hours - in the Attica Region, with the most likely places of exposure being the Regional Units of West Attica, Piraeus and Islands (in the Municipalities of Aspropyrgos, Korydallos and Salamina). The cases concern patients over 65 years of age, who presented with encephalitis/meningoencephalitis and had symptoms onset within the last ten days of June 2025.
Cases of West Nile virus infection occur in many countries worldwide, as well as in many European countries, on an annual basis, usually during the summer and autumn months. Since 2010, cases have occurred almost every year in our country, as well, as a result of which the re-emergence of cases is expected in each transmission period. Given the expected circulation of the virus during the current period, the National Organization for Public Health (EODY) informed healthcare professionals nationwide in May 2025 of the need to be vigilant about the disease and in early June 2025 issued a relevant Press Release to inform the public, with recommendations for taking preventive measures against mosquitoes.
As the epidemiology of the virus is determined by many factors, the areas where cases will occur cannot be predicted with certainty . This is why EODY recommends that you diligently take individual mosquito protection measures throughout the territory, throughout the mosquito circulation period, and specifically:
Use approved insect repellents for the body and space (according to the instructions for use) , mosquito nets, air conditioners/fans, and appropriate (long) clothing.
Do not leave standing water anywhere (this essentially helps to limit mosquito breeding grounds in private spaces).
Older people, people with immunosuppression, and people with chronic underlying diseases should adhere to individual mosquito protection measures with particular consistency, as they are at greater risk of becoming seriously ill.
Every Wednesday, EODY will publish updated reports with current epidemiological data (number of cases at the Municipality level), from which you can be informed about the Municipalities in the country where cases of the disease were recorded during the period 2025 (and in which, therefore, the virus is definitely circulating).
West Nile virus is transmitted mainly by the bite of infected "common" mosquitoes , which are infected by infected (mainly wild) birds. People who become infected do not transmit the virus further to other mosquitoes or to other people (by direct contact). In the majority of cases, infected people do not get sick at all or show only mild symptoms, while a small percentage (less than 1% of those infected) develop serious disease affecting the nervous system (mainly encephalitis or meningitis).
In each transmission period, and with the aim of timely implementation of targeted response and prevention measures, EODY carries out enhanced epidemiological surveillance of the disease and active entomological surveillance at the national level, which has been significantly strengthened in recent years. At the same time, it informs health and public health professionals and the public, immediately investigates incidents and is in constant communication and cooperation with the competent national authorities and local government authorities, which institutionally carry out mosquito control programs. The recommended prevention and response actions, based on a risk assessment in each area, are described in detail in the “Action Plan for West Nile Virus Infection” of the Ministry of Health, which aims at the standardized implementation of actions to manage and reduce the risk of virus transmission. A special inter-sectoral Working Group of the Ministry of Health is immediately conducting a risk assessment and defining the affected areas and high-risk areas