Ki Wook Yun

Community-acquired pneumonia (CAP) is the leading cause of death in children < 5 years of age worldwide. It is also one of the most frequent infectious diseases in children, leading to large antibiotic use and hospitalization even in the industrialized countries. However, the optimal management of CAP in children is still not well defined. Currently, respiratory viruses are considered the most frequent etiologic agents, but detection of viruses in the upper respiratory tract does not guarantee c

OBJECTIVES: This study aims to describe the clinical characteristics of enteroviral meningitis in association with the absence of cerebrospinal fluid (CSF) pleocytosis. DESIGN: This was a retrospective analysis of databases of patients diagnosed with enteroviral meningitis by CSF reverse transcription-PCR testing. Presence of CSF non-pleocytosis at each age group was analysed by use of the two criteria. Clinical variables were compared with regard to the presence of CSF pleocytosis. Multiple log

Pneumonia is a common pediatric infectious disease that is familiar to pediatricians and a major cause of hospitalization worldwide. Recent well-designed epidemiologic studies in developed countries indicated that respiratory viruses are detected in 30%-70%, atypical bacteria in 7%-17%, and pyogenic bacteria in 2%-8% of children hospitalized with community-acquired pneumonia (CAP). The etiological distribution of CAP varies widely by child age and the epidemiological season of the respiratory pa

PURPOSE: We investigated the molecular types of uropathogenic Escherichia coli (UPEC) by using conventional phylogrouping, multilocus sequence typing (MLST), and fimH genotyping. METHODS: Samples of patients younger than 18 years of age were collected from the Chung-Ang University Hospital over 2 years. Conventional phylogenetic grouping for UPEC strains was performed by polymerase chain reaction (PCR). Bacterial strain sequence types (STs) were classified on the basis of the results of partial

BACKGROUND: Group B streptococcus (GBS) is one of the leading causes of invasive infections in infants. This study aimed to investigate the genotypic diversity of GBS causing invasive infections in infants and to observe the prevalence of the highly virulent clone in South Korea. METHODS: Invasive strains of GBS were collected prospectively from infants admitted at 4 hospitals during 1995-2015. Serotype and multilocus sequence typing were determined. All isolates underwent polymerase chain react

BACKGROUND: The clinical spectrum of Mycoplasma pneumoniae pneumonia is widely variable. This study evaluated the clinical manifestations of M. pneumoniae pneumonia in children of different age groups and by the presence of co-detected respiratory virus. METHODS: This study included children hospitalized with M. pneumoniae pneumonia between 2010 and 2015. At the time of pneumonia diagnosis, a nasopharyngeal aspirate was analyzed for respiratory viruses by reverse transcription-polymerase chain r

The purpose of this study was to develop pneumococcal typing by multiplex PCR and compare it with conventional serotyping by quellung reaction. Pneumococcal strains used in this study included 77 isolates from clinical specimens collected from children at Seoul National University Children's Hospital from 2006 to 2010. These strains were selected as they represented 26 different serotypes previously determined by quellung reaction. Molecular type was determined by 8 sequential multiplex PCR assa

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) account for significant morbidity and mortality in patients with long-term central venous catheters (CVCs). This study was performed to identify the characteristics and risk factors of CLABSIs among children with long-term CVCs. METHODS: A retrospective review of children who had a long-term CVC in Seoul National University Children's Hospital between 2011 and 2015 was performed. Data on patient demographics, the isolated patho

BACKGROUND: Although mouse brain-derived, inactivated Japanese encephalitis vaccines (JE-MBs) have been successfully used for a long time, potential rare neurological complications have prompted the development of a Vero cell culture-derived inactivated vaccine (JE-VC). In a phase III clinical study, we aimed to compare the safety and immunogenicity of a JE-VC, KD-287 with a JE-MB, JEV-GCC, in children. METHODS: In this multicenter, double-blinded, randomized controlled trial, the study populati

A resurgence of Mycoplasma pneumoniae (MP)—the leading cause of community-acquired bacterial pneumonia, particularly in children—occurred following the COVID-19 pandemic. We aimed to investigate the clinical manifestations, macrolide resistance patterns, and therapeutic approaches related to the MP pneumonia epidemic. Children and adolescents diagnosed with MP pneumonia in September–December 2023 were screened. Clinical data were retrospectively collected from 13 major hospitals using concordant

The purpose of this study was to develop pneumococcal typing by multiplex PCR and compare it with conventional serotyping by quellung reaction. Pneumococcal strains used in this study included 77 isolates from clinical specimens collected from children at Seoul National University Children’s Hospital from 2006 to 2010. These strains were selected as they represented 26 different serotypes previously determined by quellung reaction. Molecular type was determined by 8 sequential multiplex PCR assa

Pneumolysin (Ply) and pneumococcal histidine triad protein D (PhtD) are candidate proteins for a next-generation pneumococcal vaccine. We aimed to analyze the genetic diversity and antigenic heterogeneity of Ply and PhtD for 173 pneumococci isolated from invasive diseases in Korean children. Allele was designated based on the variation of amino acid sequence. Antigenicity was predicted by the amino acid hydrophobicity of the region. There were seven and 39 allele types for the ply and phtD genes