Eunhwa Choi

BACKGROUND: This study was performed to evaluate the associations of newly recognized viruses, namely, human metapneumovirus (hMPV), human coronavirus (HCoV)-NL63, and human bocavirus (HBoV) with lower respiratory tract infections (LRTIs) in previously healthy children. METHODS: To determine the prevalences of 11 viruses--respiratory syncytial virus (RSV), adenovirus, rhinovirus, parainfluenza viruses (PIVs) 1 and 3, influenza viruses A and B, hMPV, HCoV, HCoV-NL63, and HBoV--among infants or ch

Despite the concern of replacement disease, notably by serotype 19A after 7-valent conjugate vaccine (PCV7) use, serotype 19A was increasingly recognized in Korean children before the introduction of PCV7. To understand the dynamics of serogroup 19 prevalence from 1991-2006, we serotyped 538 pediatric pneumococcal isolates. Serogroup 19 isolates (n = 126) were characterized by antimicrobial drug susceptibility, presence of mefA/ermB, and multilocus sequence typing. Overall, the proportion of ser

In this case series study, inapparent infections in children may have been associated with silent COVID-19 transmission in the community. Heightened surveillance using laboratory screening will allow detection in children with unrecognized SARS-CoV-2 infection.

Mycoplasma pneumoniae is an important cause of community-acquired pneumonia in children and young adolescents. Macrolides are recommended as the first-line therapy however, macrolide resistance rates in M. pneumoniae among children have been increasing substantially. Areas covered: This review focused on clinical characteristics and treatment of macrolide-resistant M. pneumoniae pneumonia in children. Expert commentary: Antibiotic choice should be based on in vitro activity, clinical efficacy an

Respiratory syncytial virus (RSV) is a major health problem in young children, and host response to severe disease favors a Th2 immune response. To investigate the genetic basis for RSV disease severity, linked variants of 3 Th2 cytokine genes, IL4, IL13, and IL5 (which are clustered on chromosome 5q31.1) were characterized in 105 children who were hospitalized with severe RSV infection and 315 Korean control subjects in a pilot study. A common IL4 haplotype defined at 5 loci, which includes the

The efficacy of the serotype 3 (ST3) pneumococcal conjugate vaccine (PCV) remains unclear. While the synthesis of capsular polysaccharide (CPS) of most serotypes is wzy dependent, the strains of two serotypes, 3 and 37, synthesize CPS by the synthase-dependent pathway, resulting in a polysaccharide that is not covalently linked to peptidoglycan and can be released during growth. We hypothesized that the release of CPS during growth reduces anti-type 3 CPS antibody-mediated protection and may exp

OBJECTIVE: Transmissibility of COVID-19 by children in the household is not clear. Herein, we describe children's role in household transmission of COVID-19. DESIGN AND SETTING: All paediatric COVID-19 index cases and their household members reported from 20 January to 6 April 2020 in South Korea were reviewed. The secondary attack rate (SAR) from child index case to household secondary case was calculated. Epidemiological and clinical findings of child index case-household secondary case pair w

We report changes in viral load over time in a 27-day-old neonate with coronavirus disease 2019 who presented with fever, cough, and vomiting. Severe acute respiratory syndrome coronavirus 2 RNA was detected in the nasopharynx, oropharynx, stool, saliva, plasma, and urine. The highest viral RNA copies in nasopharynx decreased over time while viral load in stool remained high.

To study genetic variation and molecular epidemiology of the G protein of respiratory syncytial virus (RSV), 253 strains from a children's hospital in Korea over 9 consecutive epidemics were analyzed. Restriction analysis of the entire G protein gene demonstrated 24 genotypes among 188 subgroup A and 6 among 65 subgroup B isolates. Two to 4 dominant genotypes of subgroup A cocirculated, and different genotypes predominated in each epidemic. Predominant genotypes were replaced with new genotypes

One hundred six cases of invasive pneumococcal infections diagnosed from 1985 to 1996 were analyzed retrospectively. The types of infection were bacteremia without focus (45%), meningitis (19%), peritonitis (17%), pneumonia (bacteremic) (16%), and others (3%). Penicillin-nonsusceptible Streptococcus pneumoniae was first detected in 1989, and its incidence increased rapidly thereafter, reaching 89% in 1995. Initial empirical regimens were of parenteral beta-lactam antimicrobials with or without a

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

The chest radiographic findings of children with M. pneumoniae pneumonia correlate well with the clinical features. Consolidative lesions were frequently observed in older children and were associated with more severe clinical features.

In conclusion, during the 2 outbreaks of M. pneumoniae infection, we found that the PCR test may be useful for the rapid diagnosis of M. pneumoniae pneumonia, particularly in young children and in immunocompromised patients and in early stage disease.

BACKGROUND: With the emergence of macrolide resistance, concerns about the efficacy of macrolides for the treatment of Mycoplasma pneumoniae (MP) pneumonia in children have been raised. This study aimed to determine the effect of macrolide resistance on the outcome of children who were hospitalized with MP pneumonia. METHODS: Between 2010 and 2015, we performed culture of MP from nasopharyngeal samples obtained from children who were hospitalized with pneumonia at five hospitals in Korea. Macrol

Background: Human coronavirus NL63 (HCoV-NL63) has recently been implicated as a common cause of croup in children. This study was performed to evaluate viruses associated with croup in children, with an emphasis on HCoV-NL63. Methods: Nasopharyngeal aspirates were prospectively collected from 182 children hospitalized with croup at Seoul National University Bundang Hospital from January 2005 to June 2009. Multiplex reverse-transcriptase polymerase chain reaction was conducted for detection of 1