Abstract Title
Trends in Enteric Virus Infections Among Children Under Five in South Korea, 2020-2024
Presenter
Sun-Whan Park, KDCA
Co-Author(s)
Yunhee Jo, Minji Lee, Deog-Yong Lee and Myung-Guk Han
Abstract Category
Molecular Epidemiology & Evolution
Abstract
Background
Acute gastroenteritis remains a significant infectious disease in South Korea despite improved living conditions. Viral gastroenteritis, in particular, continues to exhibit consistent incidence rates annually. Since 2007, South Korea has been operating EnterNet-Korea, a laboratory surveillance program monitoring the occurrence of acute gastroenteritis. This study aims to analyze the EnterNet-Korea data to investigate the trends of viral pathogens causing acute gastroenteritis in children under five over the past five years.
Methods
The Acute Diarrheal Disease Laboratory Surveillance Program is a nationwide initiative in South Korea that monitors pathogens causing acute diarrheal diseases. Approximately 70 collaborating hospitals across the country provide stool samples from patients with diarrhea. Laboratory tests are conducted by regional Institutes of Health and Environment, targeting 10 bacterial species, 5 viral species, and 4 protozoan species. The Korea Disease Control and Prevention Agency (KDCA) analyzes these test results to study pathogen prevalence trends. This study focused on five enteric viruses: norovirus, rotavirus, enteric adenovirus, astrovirus, and sapovirus. The analysis was limited to children under five years old and covered the period from 2020 to 2024, which includes the COVID-19 pandemic.
Results
From 2020 to 2024, nationwide surveillance of enteric viruses in South Korean children under five years of age revealed an average detection rate of 11.9%, with the rate reaching 13.8% in 2024 — the highest level recorded in the past five years. Norovirus accounted for 74.2% of all detected cases, maintaining its status as the predominant pathogen, with detection peaking in the winter months (January–February) and reaching its lowest levels in August. Genotypic analysis showed that the GII.4 strain of norovirus remained the dominant genotype in 2024, although its proportion declined to 47.4% compared to the previous year. Notably, the GII.17 genotype re-emerged in the second half of 2024, increasing to 6.2%, and both GII.3 (10.1%) and GII.7 (9.3%) also showed an upward trend, indicating a transition from GII.4-dominated circulation to a more diverse genotype distribution. Rotavirus was predominantly G8P[8], though its proportion decreased to 43.5%, followed by G3P[8], with an increasing diversity of genotypes observed. Enteric adenovirus was stably dominated by type F41, accounting for over 70% of cases. Astrovirus continued to be led by type 1, while sapovirus was primarily detected as GI group.
Conclusion
Between 2020 and 2024, analysis of enteric viruses in South Korean children under five revealed that norovirus consistently exhibited the highest detection rates, confirming its role as a primary pathogen. In 2024, the overall detection rate was the highest in the past five years, with significant changes observed in the genotype distribution of norovirus. Beyond norovirus, rotavirus (G8P[8]), adenovirus (F41), astrovirus (Type 1), and sapovirus (GI group) maintained their respective predominant genotypes. These findings underscore the importance of continuous genotype surveillance of enteric viruses, which is crucial for vaccine development, diagnostic kit design, and the formulation of public health policies.
Acute gastroenteritis remains a significant infectious disease in South Korea despite improved living conditions. Viral gastroenteritis, in particular, continues to exhibit consistent incidence rates annually. Since 2007, South Korea has been operating EnterNet-Korea, a laboratory surveillance program monitoring the occurrence of acute gastroenteritis. This study aims to analyze the EnterNet-Korea data to investigate the trends of viral pathogens causing acute gastroenteritis in children under five over the past five years.
Methods
The Acute Diarrheal Disease Laboratory Surveillance Program is a nationwide initiative in South Korea that monitors pathogens causing acute diarrheal diseases. Approximately 70 collaborating hospitals across the country provide stool samples from patients with diarrhea. Laboratory tests are conducted by regional Institutes of Health and Environment, targeting 10 bacterial species, 5 viral species, and 4 protozoan species. The Korea Disease Control and Prevention Agency (KDCA) analyzes these test results to study pathogen prevalence trends. This study focused on five enteric viruses: norovirus, rotavirus, enteric adenovirus, astrovirus, and sapovirus. The analysis was limited to children under five years old and covered the period from 2020 to 2024, which includes the COVID-19 pandemic.
Results
From 2020 to 2024, nationwide surveillance of enteric viruses in South Korean children under five years of age revealed an average detection rate of 11.9%, with the rate reaching 13.8% in 2024 — the highest level recorded in the past five years. Norovirus accounted for 74.2% of all detected cases, maintaining its status as the predominant pathogen, with detection peaking in the winter months (January–February) and reaching its lowest levels in August. Genotypic analysis showed that the GII.4 strain of norovirus remained the dominant genotype in 2024, although its proportion declined to 47.4% compared to the previous year. Notably, the GII.17 genotype re-emerged in the second half of 2024, increasing to 6.2%, and both GII.3 (10.1%) and GII.7 (9.3%) also showed an upward trend, indicating a transition from GII.4-dominated circulation to a more diverse genotype distribution. Rotavirus was predominantly G8P[8], though its proportion decreased to 43.5%, followed by G3P[8], with an increasing diversity of genotypes observed. Enteric adenovirus was stably dominated by type F41, accounting for over 70% of cases. Astrovirus continued to be led by type 1, while sapovirus was primarily detected as GI group.
Conclusion
Between 2020 and 2024, analysis of enteric viruses in South Korean children under five revealed that norovirus consistently exhibited the highest detection rates, confirming its role as a primary pathogen. In 2024, the overall detection rate was the highest in the past five years, with significant changes observed in the genotype distribution of norovirus. Beyond norovirus, rotavirus (G8P[8]), adenovirus (F41), astrovirus (Type 1), and sapovirus (GI group) maintained their respective predominant genotypes. These findings underscore the importance of continuous genotype surveillance of enteric viruses, which is crucial for vaccine development, diagnostic kit design, and the formulation of public health policies.