Recent Epidemiological and Clinical Features of Hospitalized Childhood Influenza Patients at A Community Hospital

Purpose: I did this study to know update epidemiological and clinical features of childhood influenza. Methods: I collected clinical informations of influenza patients who had visited and been diagnosed at the Department of Pediatrics, Yogin Severance Hospital from September 2013 to August 2016. Among them, the inpatient cases were investigated and their parameters for that mentioned above were investigated and compared among them by influenza season. Results: There were 110 hospitalized cases during last three influenza seasons. The most prevalent month of them was February (49.1%). Their mean age was 66.9±47.3 months old. Male to female ratio was 0.9:1. Regarding to influenza antigenic type, there were 65 type A cases and 45 type B cases. Their major clinical manifestations were fever (100.0%), cough (92.7%), rhinorrhea (80.0%), sputum (71.8%). Thirty-five cases (31.8%) showed at least one of three gastrointestinal symptoms such as vomiting, abdominal pain, and diarrhea. Their mean admission duration was 3.2±1.2 days. Seasonal hospitalized rate was decreased from 22.8 % in 2014-2015(A) season to 11.0% in 2015-2016(B) season ( P =0.015) and increased to 22.8% in 2015-2016(C) season ( P =0.006). The composition rate of type B was also diminished from 40.5% in A season to 21.4% in B season and elevated to 45.7% in C season. The most prevalent month per season was different among them ( P <0.05). When comparing clinical parameters by season, the incidence of rhinorrhea (A season=75.7% vs. B season=92.0%) and lethargy (A season=18.9% vs B season=5.1%) showed seasonal difference ( P <0.05), but others such as admission duration, incidence and duration of pre-and post admission fever, frequency of cough, sputum, gastrointestinal and lower respiratory tract involvements did not. Incidence of hyponatremia was increased from 16.2% in A season to 37.2% in C season ( P =0.027). Season C also showed lower serum sodium ( P