The first case of West Nile virus infection for the 2024 transmission period was diagnosed in the country, with the most likely exposure site being the Larissa Regional Unit (Municipality of Larissa).
According to the EODY update, the incident presented a case of mild encephalitis, the onset of symptoms was in the last ten days of June 2024 and the patient was discharged from hospital. We note that during the transmission period last year, 2023, the Larissa Region was one of the main centers of circulation of the virus in our country, before the flooding phenomena in September.
Outbreaks of West Nile virus infection occur annually in many countries around the world, as well as in many European countries, usually during the summer and autumn months.
Since 2010, cases have appeared almost every year in our country as well, and – therefore – it is considered expected the recurrence of incidents in each transmission period. In May 2024, EODY informed health professionals across the country about the need to be alert to the disease and issued a relevant press release for public information, with recommendations for preventive measures against mosquitoes.
Estimates of intense circulation of the virus
EODY estimates that – due to mild winter temperatures – the circulation of the virus may be intense during the current period and recommends that you take diligent preventive measures against mosquitoes.
Since the epidemiology of the virus is determined by many factors, outbreak areas cannot be predicted with certainty.
Security measures
Therefore, EODY recommends that individual protection measures against mosquitoes be observed throughout the territory, throughout the period of mosquito circulation:
· Use approved body and environmental repellents (according to the instructions for use), screens, mosquito nets, air conditioning/fans, suitable clothing (long).
· Do not leave standing water anywhere (thus helping to limit mosquito breeding sites in private areas).
Elderly people and people with underlying chronic illnesses should take their measures with particular consistency.
West Nile virus is transmitted primarily through the bite of infected “common” mosquitoes, which are then infected by infected (mostly wild) birds. Infected people do not transmit the virus to other mosquitoes or to other people (through direct contact).
Most people who become infected do not become ill or have only mild symptoms, while a small percentage (less than 1% of people who become infected) develop serious illness affecting the nervous system (mostly encephalitis or meningitis). Older people (over 50 years of age), as well as people with immunosuppression and underlying chronic diseases, are at greater risk of becoming seriously ill.
In order to implement timely targeted response and prevention measures, EODY carries out enhanced epidemiological surveillance of the disease and actions to inform health professionals and the public, and is in constant communication and cooperation with the competent national and local authorities. A special intersectoral Working Group of the Ministry of Health immediately carries out a risk assessment and definition of “affected” and “high-risk” areas.
Indeed, this year the Ministry of Health, in collaboration with EODY, proceeded to develop a comprehensive “Action Plan for West Nile Virus Infection”, with the aim of standardized implementation of actions to reduce the risk of virus transmission, based on a risk assessment.
Furthermore, especially for this year’s transmission season of 2024, as part of an integrated management to prevent the transmission of mosquito-borne diseases, EODY has organized and is conducting an extended program of enhanced entomological surveillance in the country, through the development of a cooperation network with public bodies/wider public sector, with extension of the mosquito trap network, with standardized methodology and representative geographical distribution. Especially in the Thessaly region, in response to the flooding phenomena of September 2023, EODY – in collaboration with the University of Thessaly – has continued the project of enhanced entomological surveillance during the winter and spring months.
More information about West Nile virus and mosquito-borne protective measures can be found on the EODY website. You can also find out about current epidemiological data (number of cases at the municipality level) from the weekly updated infection surveillance reports, which will be published on the EODY website every Wednesday.