단일 지역사회 병원에서 관찰된 소아 인플루엔자 유행 양상의 최근 변화

Abstract

Purpose: During recent influenza seasons, the well-documented epidemiological features since 2011 such as its emerging from January, peak on February, two wave in a season were not found. So I did this study to know the recent changes of epidemiological features. Methods: I collected and investigated the epidemiological and demographic informations of influenza patients who had visited and been diagnosed at the Department of Pediatrics and emergency room, Yogin Severance Hospital from June 2016 to May 2018 under 18 years old. Its infection was detected by rapid immunochromatographic assay for the influenza antigen. They were grouped into season A (June 2016~May 2017) and season B (June 2017~May 2018) by the detection time and compared with each other by season. Results: There were total 662 cases and they were found from November to May and the peak month was December (68.3%). Their mean age was 7.0±4.4 years old and male to female ratio was 1.3:1. There were 309 cases (46.7%) with 7 years old and over. Their monthly age were decreased from November until March and started to increase from April to May (P <0.001). When comparing their epidemiological features by season, there were significant differences between season A and season B regarding to age (7.8±4.4 years old vs. 6.0±4.1 years old, P <0.001), the composition rates of influenza type A (96.4% vs. 35.2%, P <0.001) and cases in December (86.3% vs. 47.0%, P =0.002), respectively. There was no second wave of epidemic in season B. Conclusion: The epidemiological features of childhood influenza are changed. They are also changed by season. Almost half of childhood influenza patients are within school year age. These findings clarify the significance continuous monitoring for them and should be applied to the prevention policy.