Seasonal flue in Greece is showing a significant increase in the last couple of weeks, with the National Public Health Organization (EODY) issuing a warning message to citizens.
At the center of this year’s outbreak is the K strain of influenza A, which, according to experts, shows increased transmissibility and is associated with a more severe clinical picture.
Hospitalizations more than doubled in the last week of 2025, especially during Christmas where people crowded indoors.
However the peak of this year’s influenza is expected after children return to schools on January 8, with health experts expecting cases among children to increase dramatically.
The latest epidemiological surveillance data from EODY for the period 22–28 December 2025 show a sharp increase in cases. The admissions of patients with flu to hospitals more than doubled within a week, reaching 497, compared to 235 in the immediately previous period.
At the same time, new serious cases requiring hospitalization in Intensive Care Units were recorded, as well as another death from laboratory-confirmed flu. In total, since the beginning of the surveillance period, 15 serious cases in ICUs and three deaths have been reported, while since the beginning of 2024, the number of deaths from severe influenza has reached 151.
According to the National Institute of Public Health, a significant percentage of severe cases involves unvaccinated persons, which is a factor that intensifies the concern of the scientific community.
Flu: What do experts say about the “invasion” of the K strain
Professor of Hygiene and Epidemiology at the Medical School of the National University of Athens, Gikas Mayorkinis, points out that the prevalence of the K strain was expected. As he explains, the country is already in the heart of the respiratory infection season, which began in mid-November, with increased congregating in closed spaces.
Particular emphasis is placed on citizens over 60 years of age, emphasizing that those who have not been vaccinated should do so immediately, as the flu wave is estimated to last until mid-March.
For people over 65 years of age with underlying diseases, it is recommended to perform a diagnostic test promptly and, in the event of a positive result, to immediately contact a doctor to begin treatment within the first three to four 24 hours.
“Peak has not arrived yet”
For her part, Professor of Epidemiology and Preventive Medicine at the National University of Athens, Theodora Psaltopoulou, warns that the current flu wave is still on the rise, with the peak expected towards the end of January.
As she notes, this year’s picture reminds us that influenza continues to pose a serious threat to public health, especially for vulnerable groups, while similar pressure is also being recorded in other European countries, as well as in the United States.
Why is it called “superflu”
The term “superflu” is not a medical designation, but is used to describe periods when seasonal influenza causes more intense and prolonged symptoms. The K substrain carries mutations that make it more contagious, while it appears that it may partially evade immunity from previous illness or vaccination.
Nevertheless, the evidence so far shows that the influenza vaccine continues to offer substantial protection against serious illness and hospitalization, in both children and adults.
Symptoms and diagnosis
Seasonal influenza usually lasts from five to seven days, with gradual resolution of symptoms, which include fever, muscles pain, headache, nasal congestion, sore throat, dry cough, nausea and general malaise.
Diagnosis can be made with special detection tests from the pharynx or nose, as well as with molecular testing (PCR), which is considered the most reliable method.
EODY recommendations
EODY reiterates the strong recommendation for immediate vaccination, especially in high-risk groups, the early initiation of antiviral treatment where indicated and the strict adherence to personal protection measures, such as hand hygiene, the use of a mask in crowded conditions and staying home in case of symptoms.
source: healthreport.gr, others
 issu){kind=link}