During the 2025/2026 flu season in Croatia, as of 28 December 2025, 29,771 flu cases were reported, of which 5,051 were reported in the last, 52nd week. The lower number of flu cases reported in the last week is likely related to fewer working days and not to an actual decline in the number of cases, according to the Ministry of Health.
Flu reports were received from all counties, with the highest rate of flu reports per 100,000 inhabitants in week 52 recorded in Varaždin and Krapina-Zagorje counties.
Among the flu reports received, the incidence rate is usually highest in preschool and school-age children, and lowest in people aged 65 and over.
Compared to the same period in the last ten seasons, there has been an earlier increase in the number of flu cases. For example, since October, 29,771 cases have been reported, compared to 667 cases last season. During that period, a total of 950 patients were admitted to hospital for treatment due to flu, 45 of whom were in intensive care. Last season, a total of 69 patients were hospitalized due to flu at the same time, 3 of whom were in intensive care.
The flu season is commonly associated with excess deaths, or an increased number of deaths compared to the number of deaths outside the flu season. This is due to the fact that influenza is more likely to cause complications and death in certain risk groups, such as people aged 65 and older and those with chronic illnesses, regardless of age. It is difficult to say how many people actually die directly or, more often, indirectly from the flu (as a result of worsening of the underlying illness or complication, such as pneumonia or sepsis). Five deaths due to influenza and its complications have been reported so far this season.
According to data from the National Influenza Reference Center of the Croatian Institute of Public Health, 41% of positive influenza cases were recorded in the last week. Influenza A viruses were detected in the positive cases, with 50% of subtyped samples showing type A/H3 viruses and 50% showing type A/H1N1pdm09 viruses.