Pediatr Infect Vaccine.  2020 Dec;27(3):171-179. 10.14776/piv.2020.27.e21.

Epidemiological Characteristics of Influenza in Children during the 2017– 2018 and 2018–2019 Influenza Seasons in Jeju, Korea

• Kim YJ
• Choe YJ
• Choi JH

• KMID: 2511819
• DOI: http://doi.org/10.14776/piv.2020.27.e21

Abstract

Purpose
In Korea, seasonal influenza is an important respiratory illness afflicting children every year. We aimed to investigate the childhood epidemiology in Jeju during the 2017–2018 and 2018–2019 seasons.
Methods
Children aged <13 years, who were tested for influenza at the Jeju National University Hospital during the 2017–2018 and 2018–2019 influenza seasons, were included. Demographics and the influenza test results were retrospectively reviewed from their medical records.
Results
This study included 5,219 cases of influenza-like illness (ILI) (2017–2018: n=2,279; 2018–2019: n=2,940). The mean age of the eligible children was 2.85±2.79 years, and the most common age among ILI patients in each season was 1 year group. There were 902 (17.3%, 902/5,219) confirmed influenza cases during the 2 seasons. The rate of influenza confirmed by rapid influenza diagnostic test or polymerase chain reaction among ILI patients in the 2017–2018 and 2018–2019 seasons was 10.4% (236/2,279) and 10.3% (303/2,940) for influenza A, and 9.1% (208/2,279) and 5.3% (155/2,940) for influenza B, respectively. The mean age of influenza-confirmed cases was 4.09 years and 5.05 years in the 2017–2018 and 2018–2019 seasons, respectively (P<0.05). Weekly distribution of influenza was similar to that of ILI in the clinical sentinel surveillance system in both seasons.
Conclusion
The difference in the influenza epidemic trend and age-group distribution between the 2017–2018 and 2018–2019 seasons was distinct in Jeju. Steady epidemiological studies on influenza in Jeju are needed for comparison with other regions of Korea.

Keyword

Influenza; Epidemiology; Child