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

Background@#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). @*Methods@#A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella 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. @*Results@#A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P 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.

Assessment of dietary quality and nutrient intake of obese children in Changwon area / 한국영양학회지

Purpose@#In this study, we assessed the intake of nutrients and food groups and analyzed the nutrition quotient of obese children in South Korea. The hypothesis was that dietary quality and nutrient intake are related to the body mass index (BMI) of obese children. @*Methods@#The participants included 48 children (20 boys and 28 girls). Based on the guidelines for the age-for-body mass index provided by the Korean National Growth Charts for children and adolescents, the participants were divided into 3 groups: overweight, BMI ≥ 85th percentile; obese, BMI ≥ 95th percentile; severely obese, BMI ≥ 99th percentile. @*Results@#The energy distribution showed that the carbohydrate ratio was significantly higher in the overweight group (p < 0.01), whereas the fat ratio was significantly higher in the obese and severely obese groups (p < 0.05). Thus, in the overweight and obese groups, the percent body fat was negatively associated with the carbohydrate ratio (p < 0.05) but was positively associated with the fat ratio (p < 0.05). The Dietary Reference Intakes (DRI) data revealed that the intake levels of protein, vitamin B 1 , vitamin B 12 , and sodium were higher in all groups. Intakes of fiber, calcium, potassium, and magnesium were insufficient in all groups, and the DRI percent for protein was significantly higher in the obese and severely obese groups than in the overweight group. No significant differences were obtained in food group patterns or Nutrition Quotient (NQ) scores among the 3 groups. According to the evaluation results by food record and NQ, a significant difference was obtained in the dietary quality of obese children. @*Conclusion@#We conclude that a higher intake of fat enhances weight gain. Based on the study results, we propose that the guidelines should consider the energy distribution of carbohydrate and fat intake to prevent and control obesity among Korean children.

Immunogenicity and Safety of a Newly Developed Tetanus-Diphtheria Toxoid (Td) in Healthy Korean Adolescents: a Multi-center, Randomized, Doubleblind, Active-Controlled Phase 3 Trial

Background@#Although the combination tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) is recommended at adolescence in developed countries, the tetanus and diphtheria toxoid vaccine (Td), which is less costly, is recommended instead in some parts of the world. A new Td, BR-TD-1001, was developed by a Korean manufacturer for distribution to endemic regions and for use in the initial step of novel Tdap development. @*Methods@#This phase 3, randomized, double-blind, multi-center trial, conducted in Korea, aimed to evaluate the immunogenicity and safety of BR-TD-1001. Healthy children aged 10 to 12 years were randomized 1:1 to receive either BR-TD-1001 or the control Td (Td-pur, GlaxoSmithKline). Antibodies were measured using enzyme-linked immunosorbent assay. @*Results@#A total of 218 subjects (BR-TD-1001, n = 108; control, n = 110) were enrolled and included in the safety analysis. Vaccine-mediated antibody responses were similar in both groups. We confirmed the non-inferiority of BR-TD-1001 against the control, Td; 100% of both groups achieved seroprotection against diphtheria and tetanus. Furthermore, there was no significant difference between groups in the proportion of participants who demonstrated boost responses against diphtheria and tetanus toxoids. The incidence of solicited local and systemic adverse events (AEs), unsolicited AEs, and serious AEs did not differ significantly between groups. @*Conclusion@#The BR-TD-1001 satisfied the immunological non-inferiority criterion against diphtheria and tetanus, with a clinically acceptable safety profile.

Diagnostic Impact of Clinical Manifestations of Group A Streptococcal Pharyngitis

This study aims to identify the clinical characteristics for diagnosing streptococcal pharyngitis. The correlation between eighteen clinical manifestations and rapid antigen detection test results was analyzed. Among 205 patients, five clinical manifestations, pharyngeal hemorrhage (odds ratio [OR] = 11.85), palatal hemorrhage (OR = 9.32), tonsillar swelling (OR = 4.37), rash (OR = 3.02), and enlarged cervical nodes (OR = 1.91), were significantly correlated with group A Streptococcus (GAS) pharyngitis. Traditional indicators such as fever, pharyngeal redness, acute onset, headache, rhinorrhea, cough, tonsillar exudate, and cervical tenderness were not statistically related to GAS pharyngitis. Therefore, physicians should be cautious in using these traditional indicators

Diagnostic Impact of Clinical Manifestations of Group A Streptococcal Pharyngitis

This study aims to identify the clinical characteristics for diagnosing streptococcal pharyngitis. The correlation between eighteen clinical manifestations and rapid antigen detection test results was analyzed. Among 205 patients, five clinical manifestations, pharyngeal hemorrhage (odds ratio [OR] = 11.85), palatal hemorrhage (OR = 9.32), tonsillar swelling (OR = 4.37), rash (OR = 3.02), and enlarged cervical nodes (OR = 1.91), were significantly correlated with group A Streptococcus (GAS) pharyngitis. Traditional indicators such as fever, pharyngeal redness, acute onset, headache, rhinorrhea, cough, tonsillar exudate, and cervical tenderness were not statistically related to GAS pharyngitis. Therefore, physicians should be cautious in using these traditional indicators

Performance Evaluation of STANDARD F Strep A Ag FIA for Diagnosis of Group A Streptococcal Pharyngitis / 대한임상미생물학회지

Background@#Pharyngitis is one of the most common conditions encountered in primary health care facilities. Accurate differentiation of group A streptococcus (GAS) infection from viral infection is difficult. The STANDARD F Strep A Ag FIA (SD BIOSENSOR, Korea) is a rapid antigen detection test (RADT) that has been recently developed for diagnosing GAS pharyngitis. In this study, we evaluated the diagnostic performance of the STANDARD F Strep A Ag FIA and compared the results between the RADT and conventional throat culture. @*Methods@#Throat swab samples were obtained from a total of 372 children presenting pharyngitis symptoms in five pediatric clinics in Changwon, Korea from July 2018 to October 2019. A comparative study between STANDARD F Strep A Ag FIA and Sofia Strep A FIA (Quidel, USA) was performed. Two throat swabs were taken simultaneously from each patient for RADT. The third throat swab was stored in a transport tube containing Stuart's transport medium for culture. Performance and kappa index of STANDARD F Strep A Ag FIA were evaluated. @*Results@#GAS infection was detected in 29.3% (109/372) patients, using the STANDARD F Strep A Ag FIA. The sensitivity, specificity, positive predictive value, and negative predictive value were 95.0%, 95.2%, 88.1%, and 98.1%, respectively. The STANDARD F Strep A Ag FIA showed an excellent concordance rate of 96.5% and a kappa value of 0.89 compared to Sofia Strep A FIA. @*Conclusion@#The STANDARD F Strep A Ag FIA demonstrated an excellent performance along with Sofia Strep A FIA for the diagnosis of GAS pharyngitis.

Evaluation of the SD Bioline Strep A Ultra Test in Relation With Number of Colony Forming Units and Color Intensity

BACKGROUND: The SD Bioline Strep A Ultra (SD, Yongin, Korea) is a recently developed rapid antigen detection test (RADT) for diagnosing bacterial pharyngitis caused by Group A Streptococcus, We evaluated the performance of SD Bioline Strep A Ultra, using the number of colony forming units and color intensity. METHODS: Three throat swabs each were taken from 343 children with pharyngitis who visited pediatric clinics. We evaluated the performance of SD Bioline Strep A Ultra and compared its positive rate with the number of colony forming units, using the Fisher exact test. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value (95% confidence interval) were 97.4% (94.0–99.1%), 90.8% (85.0–94.9%), 93.0% (88.5–96.1%), and 96.5% (92.0–98.9%), respectively. Positive rate significantly differed by number of colony forming units (P=0.021). ROC plot for color intensity showed 0.938 of AUC (area under curve). CONCLUSIONS: SD Bioline Strep A Ultra showed excellent performance, and its positive rate differed by the number of colony counts. This RADT could be used as a sensitive and semi-quantitative method detecting bacterial pharyngitis.

Erratum: Addition of a Co-Author: Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (2006–2010): a Retrospective Multicenter Study

The authors regret that one co-author (Kyung-Hyo Kim) was missing in the article.

Clinical Features of Staphylococcal Scalded Skin Syndrome Caused by Community-Associated Methicillin-Resistant Staphylococcus aureus in Changwon City, Korea, during 2006 and 2015

PURPOSE: We investigated the clinical features and epidemiology of staphylococcal scalded skin syndrome (SSSS) from year 2006 to 2015 in Changwon city, Korea. METHODS: We reviewed medical records of 69 patients diagnosed with SSSS from year 2006 to 2015. Antibiotic susceptibility testing was performed by agar dilution method. Methicillin-resistant Staphylococcus aureus (MRSA) was phenotypically identified by oxacillin susceptibility testing and genotypically confirmed by the existence of the mecA gene. RESULTS: The median age of patients was 2.0 years (range 0.2–6 years). Three (4.3%), 53 (76.8%), and 13 (18.9%) patients showed the generalized type, the intermediate type, and the abortive type, respectively. Patients occurred throughout the year, but most patients occurred between July and October. MRSA was isolated from 54 of the 60 patients regardless of the clinical types. All patients recovered without any complications. CONCLUSIONS: There was a constant occurrence of SSSS patients caused by MRSA in Changwon area during 2006 and 2015. It is needed to constantly monitor the occurrence of patients with SSSS.

Safety and Immunogenicity of an Egg-Cultivated Quadrivalent Inactivated Split-virion Influenza Vaccine (GC3110A) in Healthy Korean Children: a Randomized, Double-blinded, Active-controlled Phase III Study

BACKGROUND: The frequency with which the 2 B lineages have been found to cocirculate in a season has been on the rise, which has spurred the need for a quadrivalent influenza vaccine (QIV) to protect against both B lineages. The World Health Organization (WHO) recommended that QIV include both B lineages beginning in the 2013–2014 flu season. This study was conducted to evaluate the immunogenicity and safety of an egg-cultivated QIV in healthy Korean children and adolescents aged ≥ 6 months to < 19 years. METHODS: A total of 528 subjects were randomized 4:1 to receive either a QIV (GC3110A) or a trivalent influenza vaccine. Hemagglutination inhibition antibody responses were assessed 28 days after the last dose. Safety was also evaluated. RESULTS: The proportion of subjects in the GC3110A group who achieved seroconversion was confirmed to exceed 40% across all age groups. The proportion of subjects aged ≥ 6 months to < 3 years in the GC3110A group who achieved seroprotection failed to meet the Ministry of Food and Drug Safety (MFDS) standard of 70%. Potential causes may include the small number of subjects, as well as the small dosage. However, results pertaining to the other age groups satisfied the MFDS standard. The safety profile was also comparable to that of the control. CONCLUSION: The new quadrivalent split influenza vaccine may offer broader protection to children and adolescents aged ≥ 3 years to < 19 years of age against both influenza B lineages than the existing trivalent influenza vaccines (Registered at the ClinicalTrials.gov NCT02541253).

Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (2006–2010): a Retrospective Multicenter Study

BACKGROUND: Invasive bacterial infections in apparently immunocompetent children were retrospectively analyzed to figure causative bacterial organisms in Korea. METHODS: A total of 947 cases from 25 university hospitals were identified from 2006 to 2010 as a continuance of a previous 10-year period study from 1996 to 2005. RESULTS: Escherichia coli (41.3%), Streptococcus agalactiae (27.7%), and Staphylococcus aureus (27.1%) were the most common pathogens in infants < 3 months of age. S. agalactiae was the most prevalent cause of meningitis and pneumonia and E. coli was the major cause of bacteremia without localizing signs in this group. In children 3 to 59 months of age, Streptococcus pneumoniae (54.2%), S. aureus (20.5%), and Salmonella spp. (14.4%) were the most common pathogens. S. pneumoniae was the leading cause of pneumonia (86.0%), meningitis (65.0%), and bacteremia without localizing signs (49.0%) in this group. In children ≥ 5 years of age, S. aureus (62.8%) was the predominant pathogen, followed by Salmonella species (12.4%) and S. pneumoniae (11.5%). Salmonella species (43.0%) was the most common cause of bacteremia without localizing signs in this group. The relative proportion of S. aureus increased significantly over the 15-year period (1996–2010) in children ≥ 3 months of age (P < 0.001), while that of Haemophilus influenzae decreased significantly in both < 3 months of age group (P = 0.036) and ≥ 3 months of age groups (P < 0.001). CONCLUSION: S. agalactiae, E. coli, S. pneumoniae, and S. aureus are common etiologic agents of invasive bacterial infections in Korean children.

Clinical Comparison of Influenza A and B Virus Infection in Hospitalized Children

PURPOSE: The objective of this study was to compare the clinical characteristics of influenza A and B infections and analyze the effect of oseltamivir in hospitalized children. METHODS: We investigated children under the age of 15, who were diagnosed with influenza A/H1N1, A/H3N2, or B from January to April 2014. The subjects were admitted to the Changwon Fatima Hospital and diagnosed using a rapid antigen test from nasopharyngeal swabs. The medical records of the patients were retrospectively reviewed. RESULTS: A total of 302 pediatric patients with influenza were enrolled. Influenza B infection was the most common type (n=187, 61.9%), followed by A/H3N2 (n=100, 33.1%) and A/H1N1 (n=15, 5.0%). Compared to patients diagnosed with influenza A, patients diagnosed with influenza B were older (P=0.005), and the duration of fever was significantly longer (P=0.001). A total of 161 patients (53.3%) had been vaccinated against influenza during the season, before admission. Among the patients infected with A/H3N2 and B, the duration of fever was shorter in oseltamivir recipients compared to oseltamivir non-recipients (P=0.026 and P=0.004, respectively). CONCLUSIONS: There were significant differences between influenza A and B groups in terms of age, demographics, and clinical course. Although the effectiveness of oseltamivir on influenza differs according to the type of influenza, our data provides evidence that oseltamivir is beneficial for both A and B infections.

Clinical Characteristics of Pertussis Epidemic in Changwon

PURPOSE: Pertussis can be prevented with a vaccine. Despite this, there have been an increasing number of cases worldwide, and also in Korea. This study aimed to investigate the epidemiology and clinical characteristics of the recent outbreak in the Changwon area. METHODS: Patients who visited Changwon Fatima Hospital from July 2015 to March 2016 with respiratory symptoms, including spasmodic cough, cough induced vomiting, inspiratory ‘intake’ sound (whooping), and a night-time cough for >1 week were included in this study. Respiratory specimens were collected from patients and a polymerase chain reaction (PCR) and detected anti-pertussis immunoglobulin G enzyme-linked immunosorbent assay kit test were performed. Patients with underlying diseases, or those who had received a DTaP or Tdap vaccination in recent 1 year were excluded. RESULTS: Pertussis was diagnosed in 37 of 50 patients, two patients were positive according to the PCR, and 37 patients were positive according to serologic tests. The age distribution of the patients was 1 month to 15 years. After administering antibiotics, all patients recovered without complications. CONCLUSIONS: A pertussis outbreak occurred in Changwon in 2015 and 2016. This data can provide the basis for further study on the epidemiology of pertussis in Korea.

Etiology of Acute Pharyngotonsillitis in Children: The Presence of Viruses and Bacteria

PURPOSE: The purpose of this study was to investigate the etiology of acute pharygotonsillitis in pediatric patients. METHODS: Pharyngeal swabs from patients with acute pharyngotonsillitis were evaluated for viruses and bacterial organisms from March 2010 through March 2011. RESULTS: Of 615 patients, potentially pathogenic bacteria were isolated in 40 (6.5%), viruses were isolated in 310 (50.4%), and no pathogens were isolated in 267 patients (43.4%). Both viral and bacterial pathogens were found in 2 (0.3%). Of 40 patients with bacterial pathogens, group A streptococci were found in 31 (77.5%). Among 310 patients with virus infection, adenovirus was the most frequently recovered (203 patients; 65.5%), followed by rhinovirus (65 patients; 21.0%), enterovirus (43 patients; 13.9%) and coronavirus (18 patients; 5.8%). There were 25 patients who had been coinfected with 2 viruses. In viral pharyngotonsillitis, cough, rhinorrhea, conjunctivitis and diarrhea were prominent. On the other hand, pharyngeal injection and pharyngeal petechiae were prominent in bacterial pharyngotonsillitis. CONCLUSIONS: Virus infection was a big part of acute pharyngotonsillitis and there were differences in clinical manifestations among viral and bacterial infections. Therefore, we need to distinguish between virus infection and bacterial infection using clinical signs for preventing the abuse of antibiotics.

Early Changes in the Serotype Distribution of Invasive Pneumococcal Isolates from Children after the Introduction of Extended-valent Pneumococcal Conjugate Vaccines in Korea, 2011-2013

This study was performed to measure early changes in the serotype distribution of pneumococci isolated from children with invasive disease during the 3-year period following the introduction of 10- and 13-valent pneumococcal conjugate vaccines (PCVs) in Korea. From January 2011 to December 2013 at 25 hospitals located throughout Korea, pneumococci were isolated among children who had invasive pneumococcal disease (IPD). Serotypes were determined using the Quellung reaction, and the change in serotype distribution was analyzed. Seventy-five cases of IPD were included. Eighty percent of patients were aged 3-59 months, and 32% had a comorbidity that increased the risk of pneumococcal infection. The most common serotypes were 19A (32.0%), 10A (8.0%), and 15C (6.7%). The PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, 23F, and 6A) accounted for 14.7% of the total isolates and the PCV13 minus PCV7 types (1, 3, 5, 7F and 19A) accounted for 32.0% of the total isolates. Serotype 19A was the only serotype in the PCV13 minus PCV7 group. The proportion of serotype 19A showed decreasing tendency from 37.5% in 2011 to 22.2% in 2013 (P = 0.309), while the proportion of non-PCV13 types showed increasing tendency from 45.8% in 2011 to 72.2% in 2013 (P = 0.108). Shortly after the introduction of extended-valent PCVs in Korea, serotype 19A continued to be the most common serotype causing IPD in children. Subsequently, the proportion of 19A decreased, and non-vaccine serotypes emerged as an important cause of IPD. The impact of extended-valent vaccines must be continuously monitored.

A Survey of Serum Bactericidal Antibodies against Neisseria meningitidis Serogroups A, C, W and Y in Adolescents and Adults in the Republic of Korea

BACKGROUND: This descriptive epidemiological study aimed to assess the prevalence of serum bactericidal antibodies against Neisseria meningitidis serogroups A, C, W and Y in adolescents and adults in the Republic of Korea. MATERIALS AND METHODS: In total, 987 subjects aged 11-55 years from five geographical regions of Korea were included in the study. Human serum bactericidal assay (hSBA) was used to measure hSBA titres for serogroups A, C, W and Y. Percentages of subjects with hSBA titres ≥4 and ≥8, geometric mean titres (GMTs), and associated 95% confidence intervals (CIs), were estimated. Analysis was performed for the entire study population and stratified by age group or region. No statistical hypotheses were tested. RESULTS: The highest percentage of subjects with hSBA titres ≥8 was observed for serogroup W (74%), was similar for serogroups C (34%) and Y (36%), and was lowest for serogroup A (9%). The percentages of subjects with hSBA titres ≥4 were similar to those with hSBA titres ≥8 for all serogroups. GMTs were 2.56 µg/mL (serogroup A), 5.14 µg/mL (serogroup C), 22.63 µg/mL (serogroup W) and 5.28 µg/mL (serogroup Y). Similar trends in GMTs across serogroups were seen for individual regions and age groups. The highest GMTs for serogroups A, W and Y were recorded in the >19-29 years group, and for serogroup C in the >49-55 years group. Across all regions, GMTs were very similar for serogroups A, C and Y, while more variation was seen for serogroup W. CONCLUSION: In the Korean population, among Neisseria meningitidis serogroups A, C, W and Y, serum bactericidal antibodies were most prevalent against serogroup W and least prevalent against serogroup A. These trends were maintained across age groups and regions. The highest GMTs for serogroups A, W and Y were observed in the >19-29 years group. The reasons behind the observed differences in prevalence of bactericidal antibodies against the serogroups are currently not understood, although carriage and cross-reactivity of the assay may be important influences.

Detection of Rotavirus Genotypes in Korea 5 Years after the Introduction of Rotavirus Vaccines

Rotavirus (RV) is one of the most important viral etiologic agents of acute gastroenteritis (AGE) in children. Although effective RV vaccines (RVVs) are now used worldwide, novel genotypes and outbreaks resulting from rare genotype combinations have emerged. This study documented RV genotypes in a Korean population of children with AGE 5 yr after the introduction of RVV and assessed potential genotype differences based on vaccination status or vaccine type. Children less than 5-yr-old diagnosed with AGE between October 2012 and September 2013 admitted to 9 medical institutions from 8 provinces in Korea were prospectively enrolled. Stool samples were tested for RV by enzyme immunoassay and genotyped by multiplex reverse-transcription polymerase chain reaction. In 346 patients, 114 (32.9%) were RV-positive. Among them, 87 (76.3%) patients were infected with RV alone. Eighty-six of 114 RV-positive stool samples were successfully genotyped, and their combinations of genotypes were G1P[8] (36, 41.9%), G2P[4] (12, 14.0%), and G3P[8] (6, 7.0%). RV was detected in 27.8% of patients in the vaccinated group and 39.8% in the unvaccinated group (P=0.035). Vaccination history was available for 67 of 86 cases with successfully genotyped RV-positive stool samples; RotaTeq (20, 29.9%), Rotarix (7, 10.4%), unvaccinated (40, 59.7%). The incidence of RV AGE is lower in the RV-vaccinated group compared to the unvaccinated group with no evidence of substitution with unusual genotype combinations.

A Case of Posterior Reversible Leukoencephalopathy Syndrome Following Poststreptococcal Glomerulonephritis

Posterior reversible leukoencephalopathy syndrome is a clinical radiographic syndrome of many causative factors. Sudden onset headache, vomiting, altered mental status, blurred vision and seizures are main symptoms shown in posterior reversible leukoencephalopathy syndrome. In addition, it typically shows radiological findings of edema in the white matter of posterior cerebrum, being in commonly bilateral but asymmetric. We report a case of poststreptococcal glomerulonephritis (PSGN) presenting as posterior reversible leukoencephalopathy syndrome. Immediate control of hypertension resulted in rapid and complete neurological recovery.

A Case of Acute Idiopathic Thrombocytopenic Purpura Following Influenza B Virus Infection

Virus-associated immune thrombocytopenic purpura (ITP) can occur following common viruses, but cases of ITP associated with influenza infection has seldom been reported. In this report we describe a previously healthy 5-year-old boy who admitted with fever, flu-like symptoms and a few bruises on both legs. Severe thrombocytopenia were found. Bone marrow aspirates and biopsy showed no abnormalities and results of coagulation tests were all in normal limit. Real-time polymerase chain reaction was positive for influenza B infection. The patient fully recovered with intravenous immunoglobulins and steroid therapy.

Comparison among Known Severity Scoring Scales in the Evaluation of Acute Gastroenteritis in Children / 소아감염

PURPOSE: This study aimed to evaluate the disease severity of children suffering from gastroenteritis using different scales. The results are compared and subsequently classified on the basis of the type of virus causing the disease in order to investigate the differences in clinical characteristics and disease severity according to pathogen. METHOD: This study was conducted prospectively with patients under 5 years of age diagnosed with acute gastroenteritis and hospitalized at 9 medical institutions in 8 regions across the Republic of Korea. Disease severity was evaluated using the Vesikari Scale, the Clark Scale, and the modified Flores Scale. Fecal samples collected from patients were used to detect rotavirus and enteric adenovirus by enzyme immunoassay, and for RT-PCR of norovirus, astrovirus, and sapovirus. RESULTS: There were a total of 214 patients with a male : female ratio of 1.58 : 1, of which 35 were under the age of 6 months (16.4%), 105 were aged 6-23 months (49.1%), and 74 were aged 24-59 months (34.5%). The rate of concordance between the Vesikari and Clark Scales was 0.521 (P<0.001) and, in severe cases, the Vesikari Scale was 60.7% and Clark Scale was 2.3%, indicating that the Clark Scale was stricter in the evaluation of severe cases. CONCLUSIONS: In children with gastroenteritis, there were differences in disease severity based on the scale used. Therefore, to achieve consistent results among researchers, either only a single scale or a measure of all scales should be used to determine disease severity.