Twenty-Five Year Trend Change in the Etiology of Pediatric Invasive Bacterial Infections in Korea, 1996-2020

The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria ( , , , , , , , and species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. (42.4%), (22.1%), and species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, (58.1%), followed by species (14.8%) and (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of (r = -0.430, = 0.036), (r = -0.922, < 0.001), while trend toward an increase in the relative proportion of (r = 0.850, < 0.001), (r = 0.615, = 0.001), and (r = 0.554, = 0.005). In the proportion of IBIs over a 24-year period between 1996 and 2019, we observed a decreasing trend for and and an increasing trend for , , and in children > 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.