• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.154-163
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• 2015

Purpose: Osteoarticular infections in children and adolescents are important because it can cause functional compromise if appropriate treatment is delayed. Therefore, this study was designed to describe the clinical presentations and causative organisms of osteoarticular infections in children and adolescents in order to propose early diagnosis method and an appropriate empiric antimicrobial therapy. Methods: Forty-two medical records were reviewed retrospectively, which were confirmed as osteomyelitis (OM) or septic arthritis (SA) at Department of Pediatrics or Orthopedic Surgery in patients under 18 years old of Ewha Womans University Mokdong Hospital from March 2008 to March 2015. Results: We identified 21 cases of OM, 13 cases of SA and 8 cases of OM with SA. There were 31 males and 11 females and mean age was 7.1 years old. The most common symptoms were pain and tenderness of involved site. Major involved bones were femur (10 cases, 34.5%), tibia (7 cases, 24.1%) and major involved joints were hip (9 cases, 42.9%), and knee (5 cases, 23.8%). Increased serum C-reactive protein and erythrocyte sedimentation rate were observed in 37 cases (88.1%) respectively. Magnetic resonance imaging was performed in 40 cases among 42 cases and was used to demonstrate osteoarticular infections and other adjacent infections. Nine cases (23.7%) among 38 cases and 20 cases (50.0%) among 40 cases were positive in blood culture and infected site culture respectively. The most common causative organism was Staphylococcus aureus, which was represented in 22 cases (75.9%), of which nine cases (40.9%) were resistant to methicillin. Conclusions: S. aureus was the most common causative organism of osteoarticular infections in children and adolescents and the proportion of MRSA was high in this study. Therefore, we recommend vancomycin as the first empiric antimicrobial therapy and suggest that further study is necessary to elucidate an appropriate guideline for treatment which takes into account MRSA proportion.

• Pediatric Infection and Vaccine
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• v.24 no.2
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• pp.95-101
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• 2017

Purpose: Acute bacterial gastroenteritis (ABG) can cause more severe symptoms than acute viral gastroenteritis in children. This study was aimed at determining the etiologic trends and to examine the clinical characteristics of ABG in children. Methods: We sent stool samples from the children with acute gastroenteritis who were treated at a secondary hospital located in Seoul, Korea between January 2011 and December 2014 to Seoul Metropolitan Government Research Institute of Public Health and Environment to find the causative organisms. Clinical characteristics of patient were analyzed through a medical records review. Results: Out of 664 stool samples, 183 (27.6%) yielded bacterial pathogens. Staphylococcus aureus was the most common bacterial pathogen, found in 72 cases (39.3%), even though it was only tested for since 2012. The monthly isolation rate was the highest (24.6%) in August. The isolation rate of Campylobacter spp. by patient's age group was high (16.7%) in the 12- to 18-year-age group (P=0.04). In patients with bloody stool, Campylobacter spp. was the most commonly isolated (31.0%, P=0.04). When comparing C-reactive protein, the Salmonella spp.- or Campylobacter spp.-isolated group showed higher values than the S. aureus- or pathogenic Escherichia coli-isolated group ($5.7{\pm}0.6mg/dL$ vs. $2.1{\pm}0.3mg/dL$, P<0.01). Conclusions: S. aureus, Salmonella spp., pathogenic E. coli, and Campylobacter spp. were important pathogens of ABG among children. Considering the differences in pathogens found according to age, a clinical symptom and inflammation index might be helpful in assuming the causative organism.

• Pediatric Infection and Vaccine
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• v.24 no.2
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• pp.71-78
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• 2017

Purpose: The aim of this study was to identify the pathogens of blood stream infection (BSI) in children with hemato-oncologic disorders, to analyze susceptibility patterns of microorganisms to guide empirical antimicrobial therapy, and to compare temporal trends of the pathogen and antimicrobial susceptibility with those of previous studies. Methods: We retrospectively analyzed the medical records of children with hemato-oncologic disorders whose blood culture grew pathogens at the Seoul National University Children's Hospital between 2011 and 2015. Results: A total of 167 patients developed 221 episodes of bacteremia. Among 229 pathogens, gram-negative bacteria (GNB) accounted for 69.0% (64.0% in 2002 to 2005, 63.4% in 2006 to 2010); gram-positive bacteria (GPB) accounted for 28.8% (31.3% in 2002 to 2005, 34.6% in 2006 to 2010); and fungus accounted for 2.2%. Among GNB, Klebsiella species (53.2%, 84/158) and Escherichia coli (19.6%, 31/158) were common. Staphylococcus aureus (48.5%, 32/66) and viridans streptococci (21.2%, 14/66) were frequently isolated among GPB. The susceptibilities of oxacillin and vancomycin in GPB were 54.8% and 96.9% (51.5% and 95.5% in 2002 to 2005; 34.1% and 90.5% in 2006 to 2010), respectively, whereas in GNB, the susceptibilities of cefotaxime, piperacillin/tazobactam, and imipenem were 73.2%, 77.2%, and 92.6% (75.9%, 82.8%, and 93.4% in 2002 to 2005; 62.8%, 82.9%, 93.8% and in 2006 to 2010), respectively. There were no significant differences in the proportion of etiologic agents or the antimicrobial susceptibilities between the current study and that of the previous two studies from 2002 to 2010. Overall fatality rate was 13.1%. Conclusions: GNB predominated in BSI among children with hemato-oncologic disorders. The etiology of bacteremia and antimicrobial susceptibility were comparable to those of the previous studies. Thus, piperacillin/tazobactam can be used as the initial empirical antimicrobial agent in febrile neutropenia.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.21-30
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• 2005

Purpose : Metabolic bone diseases have been mai or problems in children with renal diseases and steroid treatment is the main precipitating factor reducing bone mineral density(BMD). This study was performed to assess the prevalence of osteoporosis and to evaluate the clinical factors associated with decreased BMD in children with renal diseases. Methods : Forty-four children with renal diseases who were diagnosed at the Pediatric no phrology division of Ajou University hospital since Oct. 1994 were included. Using a new quantitative ultrasound device, BMD and the prevalence of osteoporosis were evaluated. The clinical and serological data were analyzed in association with decreased BMD. Results : A total of 44 patients were evaluated. The age at initial diagnosis was 6.7$\pm$4.2 years. At the time of evaluation, the chronological and bone age was 9.3$\pm$4.2 years and 8.2 $\pm$ 4.6 years, respectively. The renal diseases included nephrotic syndrome 24(54.5%), Henoch Schonlein purpura nephritis 7(15.9%), IgA nephropathy 6(13.9%), reflux nephropathy(RN) 2 (4.5%), and other renal disease 5(%). The prevalence of osteoporosis was 11%. There was no difference in the clinical factors between the long-term and the short-term treated steroid groups. Conclusion : The prevalence of osteoporosis was 12% in 44 children with renal diseases No significant factor was found in association with decreased BMD and there was no relationship between osteoporosis and steroid usage duration or cumulative dose. A new quantitative ultrasound, which is relatively easy to perform, especially in children, is expected to be in common use and will enable clinicians to evaluate metabolic bone disorders with ease.

• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.123-131
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• 2018

Purpose: Cytomegalovirus (CMV) infection is mostly asymptomatic but can be detrimental to certain hosts. We investigated changes of CMV seroprevalence in Koreans before and after the year 2000. Methods: We reviewed laboratory values of patients who were tested for CMV immunoglobulin G (IgG) at Samsung Medical Center, Seoul, Korea, from January 1995 to December 2015. Changes in seroprevalence were analyzed by gender, age, region, and tested year period (period 1, 1995-2005 vs. period 2, 2006-2015). Results: Overall CMV seropositivity was 94.1% (10,900/11,584). There was no significant difference for CMV seropositivity among the two periods (94.2% vs. 94.1%) (P=0.862). CMV seropositivity in the 11 to 20-year age group in period 2 (78.8%) was significantly lower than that of period 1 (89.9%) (P=0.001). The seropositivity of individuals aged 31-40 years (97.4%) was significantly higher than that of younger age groups (P<0.001) and lower than that of older age groups (P<0.001). Of 2,441 females of reproductive age (from 15 to 49), CMV seropositivity was 97% (2,467/2,441). The seropositivity in women aged 20-24-years was higher than that of men in the same age group (97.6% vs. 85.6%, P=0.003). No significant difference was observed among different regions. Conclusions: Overall CMV seropositivity of Koreans was estimated to be 94% and the average seropositivity of reproductive women was 97%. Monitoring of the changes in seroprevalence including the reproductive age group is needed in the future.

• Pediatric Infection and Vaccine
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• v.28 no.2
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• pp.92-100
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• 2021

Purpose: Rapid detection of etiologic organisms is crucial for initiating appropriate therapy in patients with central nervous system (CNS) infection. This study aimed to evaluate the diagnostic value of the BioFire^® Meningitis/Encephalitis (ME) panel in detecting etiologic organisms in cerebrospinal fluid (CSF) samples from febrile infants. Methods: CSF samples from infants aged <90 days who were evaluated for fever were collected between January 2016 and July 2019 at the Seoul National University Children's Hospital. We performed BioFire^® ME panel testing of CSF samples that had been used for CSF analysis and conventional tests (bacterial culture, Xpert^® enterovirus assay, and herpes simplex virus-1 and -2 polymerase chain reaction) and stored at -70℃ until further use. Results: In total, 72 (24 pathogen-identified and 48 pathogen-unidentified) CSF samples were included. Using BioFire^® ME panel testing, 41 (85.4%) of the 48 pathogen-unidentified CSF samples yielded negative results and 22 (91.7%) of the 24 pathogen-identified CSF samples yielded the same results (enterovirus in 19, Streptococcus agalactiae in 2, and Streptococcus pneumoniae in 1) as those obtained using the conventional tests, thereby resulting in an overall agreement of 87.5% (63/72). Six of the 7 pathogen-unidentified samples were positive for human parechovirus (HPeV) via BioFire^® ME panel testing. Conclusions: Compared with the currently available etiologic tests for CNS infection, BioFire^® ME panel testing demonstrated a high agreement score for pathogen-identified samples and enabled HPeV detection in young infants. The clinical utility and cost-effectiveness of BioFire^® ME panel testing in children must be evaluated for its wider application.

• Pediatric Infection and Vaccine
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• v.29 no.2
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• pp.84-95
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• 2022

Purpose: Urinary tract infections (UTIs) are the most common serious bacterial infections in young infants. Lumbar puncture (LP) has been used to diagnose coexisting meningitis in infants under 90 days of age with suspected UTI in many hospitals. However, the incidence of bacterial meningitis associated with UTIs is low. We aimed to describe the prevalence of concomitant bacterial meningitis in young infants with UTIs. Methods: The medical records of infants with the first episode of UTI admitted to the Chung-Ang University Hospital from January 2010 to December 2019 were retrospectively reviewed. Infants aged < 90 days who underwent LP with initial evaluation were included. Demographic and clinical features, laboratory findings, and imaging findings were collected and analyzed. Results: Eighty-six infants with UTIs were enrolled in the study. The median age was 61.5 days (interquartile range, 42.3-73.8 days) and boys (90.7%) were predominant. Escherichia coli was the most common pathogen (n=80, 93.0%) and followed by Klebsiella species (n=5, 5.8%). Fifteen (18.1%) specimens produced extended spectrum β-lactamase (ESBL). Five (5.8%) infants had positive blood culture results. Seven (8.1%) infants showed pleocytosis in the cerebrospinal fluid, but none had coexisting bacterial meningitis. Twenty-four (30.8%) infants showed renal dilatation or hydronephrosis on ultrasonography. Dimercaptosuccinic acid (DMSA) scans revealed cortical defects in 17 (21.3%) infants while voiding cystourethrography revealed vesicoureteral reflux in 6 (46.2%) infants. Conclusion: Co-existing bacterial meningitis was not observed in young infants with UTIs. LP could not be routinely performed considering the clinical condition of <90 days old UTI patients.

• Pediatric Infection and Vaccine
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• v.28 no.3
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• pp.133-143
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• 2021

Purpose: This study aimed to determine the incidence of central line-associated bloodstream infection (CLABSI) in the neonatal intensive care unit (NICU), evaluate the patients' clinical characteristics, and identify the etiologic agents for guidance in prevention and treatment. Methods: A retrospective chart review study of infants classified as having CLABSI was conducted at the NICU of Seoul National University Bundang Hospital from January 2016 to December 2020. Results: Of the 45 infants, 53 had CLABSIs within a follow-up period of 18,622 catheter days. The incidence of CLABSIs was 2.85 per 1,000 catheter days. The most common catheter type was a peripherally inserted central catheter (n=47, 81%). A total of 57 pathogens were isolated, of which 57.9% (n=33) were Gram-positive bacteria, 36.8% (n=21) were Gram-negative bacteria, and 5.3% (n=3) were Candida spp. The most common pathogens were Staphylococcus aureus (n=12, 21%) and coagulase-negative staphylococci (n=12, 21%), followed by Klebsiella aerogenes (n=8, 14%). The median duration of bacteremia was 2 days, and 19 episodes showed bacteremia for 3 days or more. The mortality rate of infants within 14 days of CLABSI was 13.3% (n=6). Conclusions: This study analyzed the incidence of CLABSI and the distribution of pathogens in the NICU. Continuous monitoring of CLABSI based on active surveillance serves as guidance for empiric antibiotic use and also serves as a tool to assess the necessity for implementation of prevention strategies and their impact.

• Pediatric Infection and Vaccine
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• v.30 no.1
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• pp.20-32
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• 2023

Purpose: This study aimed to identify the etiology and risk factors of community-acquired pneumonia (CAP) requiring hospitalization in Korean children during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Clinical information of children admitted with CAP to Seoul National University Children's Hospital (SNUCH) between January 1, 2021, and February 28, 2022, was retrospectively collected and analyzed. In addition, the etiologic diagnosis and demographic data of children with CAP who were discharged at the other seven hospitals between January and February 2022 were collected. Pneumonia was diagnosed using strict criteria comprising clinical symptoms, physical examination findings, and chest radiographic findings. Results: Among 91 children hospitalized with CAP at SNUCH during the 14-month period, 68.4% were aged <5 years and 79.1% had underlying diseases. Among the 95 CAP cases, respiratory assistance was required in 70.5%, and the use of a ventilator was required in 20.0%. A total of five patients expired, all of whom were either immunocompromised or had underlying neurological diseases. Neurological diseases and immunosuppression were significantly correlated with respiratory assistance (P=0.003) and death (P=0.014). A total of 55% of the detected respiratory pathogens were viruses, the most common of which was rhinovirus at 35.9%. Among the 169 children hospitalized for CAP at the eight institutions, ≥1 respiratory virus was detected in 92.3%, among which respiratory syncytial virus (79.8%) was the most prevalent. Conclusions: Even during the COVID-19 pandemic, Korean children were hospitalized with CAP caused by seasonal respiratory viral pathogens. Although atypical and pyogenic bacteria were not detected, continuous clinical monitoring and further prospective studies should be conducted.

• Journal of the Korean Society of Radiology
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• v.83 no.2
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• pp.304-316
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• 2022

Purpose To evaluate the effect of the emergence of coronavirus disease-19 (COVID-19) on pediatric intussusception. Materials and Methods Patients (< 18 years) who were diagnosed with intussusception and received enema reduction from 2011 to 2020 were included. We reviewed the demographics, yearly/monthly/seasonal incidence of intussusception, method and failure rate of enema reduction, recurrence rate of intussusception, surgical record, and pathologic report. Subsequently, we investigated the differences in mean age, failure rate of enema reduction, and recurrence rate of intussusception between the cases in 2020 and those in the period from 2011 to 2019. Results A total of 859 enema reductions were performed during the past decade, more in males and in the age < 1 year (mean age, 22.2 months). The yearly incidence was highest in 2014 and lowest in 2020, and the monthly incidence was highest on December and September. The cases in 2020 (n = 27) had a lower mean age (18.1 months vs. 22.8 months), higher failure rate of enema reduction (7.4% vs. 2.4%), and higher recurrence rate of intussusception (14.8% vs 7.3%) compared with those that occurred between 2011 and 2019 (n = 832). However, these results did not show statistical significance (p = 0.07, p = 0.15, p = 0.14, respectively). Conclusion With the emergence of COVID-19, the number of enema reductions was remarkably decreased with a lower mean age, higher failure rate, and higher recurrence rate.