Clinico-epidemiological features of influenza in children in the 2023-2024 season

Seasonal respiratory illnesses are the main cause of morbidity during the cold season of the year both in adults and especially in children due to clinical and epidemiological peculiarities. Influenza is one of the most important seasonal diseases causing numerous illnesses every year among the population at risk (young children, adults with comorbidities, and the elderly). In this paper we present the clinico-epidemiological features of influenza in children admitted to the National Institute of Infectious Diseases “Prof. Dr. Matei Bals” between October 2023 and March 2024. During the analysed period we registered 739 cases of influenza in children, which represents 23.7% of the total admissions in the same period. Cases of influenza A (68.3 %) predominated, compared to type B (18.8 %) and unspecified (12.8 %). The majority of cases of influenza in children were determined by subtypes AH1 and AH3 in similar proportions. Clinically, the predominant forms of the disease were mild (60.2%) and severe (17.9%), with no critical cases or deaths. Epidemiologically, the peak incidence of childhood influenza was reached in the period December 2023 - January 2024 for type A and March - April 2024 for type B. Compared to the previous season the number of cases of childhood influenza was reduced by about 19.6 %. The most affected age group was 1-6 years (42.4%). The clinical picture of influenza in the children studied was dominated by “classical” general signs (fever and chills, muscle ache and fatigue, headache, altered general condition) associated with respiratory manifestations (nasal obstruction, odynophagia, dysphagia, dry cough) and digestive symptoms (abdominal pain, vomiting, poor appetite). The majority of children with influenza (97.6%) were unvaccinated, and in those vaccinated the clinical forms of the disease were milder without complications. Influenza remains an important seasonal infectious disease because of its epidemiological (many cases) and socio-economic (absenteeism, additional costs) but also medical (potential for severe evolution and even death) implications.