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Supplemental Digital Content is available in the text., Background: Invasive bacterial infection (IBI) remains a major burden of mortality and morbidity in children. As coronavirus disease 2019 (COVID-19) emerged, stringent nonpharmaceutical interventions (NPIs) were applied worldwide. This study aimed to evaluate the impact of NPIs on pediatric IBI in Korea. Methods: From January 2018 to December 2020, surveillance for pediatric IBIs caused by 9 pathogens (S. pneumoniae, H. influenzae, N. meningitidis, S. agalactiae, S. pyogenes, S. aureus, Salmonella species, L. monocytogenes and E. coli) was performed at 22 hospitals throughout Korea. Annual incidence rates were compared before and after the COVID-19 pandemic. Results: A total of 651 cases were identified and the annual incidence was 194.0 cases per 100,000 in-patients in 2018, 170.0 in 2019 and 172.4 in 2020. Most common pathogen by age group was S. agalactiae in infants < 3 months (n = 129, 46.7%), S. aureus in 3 to < 24 months (n = 35, 37.2%), Salmonella spp. in 24 to < 60 months (n = 24, 34.8%) and S. aureus in children ≥ 5 years (n = 128, 60.7%). Compared with 2018 to 2019, the incidence rate in 2020 decreased by 57% for invasive pneumococcal disease (26.6 vs. 11.5 per 100,000 in-patients, P = 0.014) and 59% for Salmonella spp. infection (22.8 vs. 9.4 per 100,000 in-patients, P = 0.018). In contrast, no significant changes were observed in invasive infections due to S. aureus, S. agalactiae and E. coli. Conclusions: The NPIs implemented during the COVID-19 pandemic reduced invasive diseases caused by S. pneumoniae and Salmonella spp. but not S. aureus, S. agalactiae and E. coli in children.

The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.

Background Nasopharyngeal (NP) colonization with Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) is common in children, and may evolve as the source of invasive infections. In Korea, the pneumococcal conjugate vaccines (PCVs) were introduced >10 years ago, enabling the authors to study the effect of the vaccine in preventing carriage. Methods NP swabs were taken and a household survey was conducted at daycare centres located in different regions of Korea in 2014 and 2019. Pneumococcal serotypes were identified using the Quellung method and sequencing. NTHi were identified based on pilA and bexA genes. Results In total, 1460 NP swabs were obtained with pneumococcal carriage rates of 36.4–42.1% and NTHi carriage rates of 36.5–26.7%. Among children carrying pneumococci, a significant increase was seen in serotype 23A between 2014 and 2019 (from 12.6% to 22.0%; P=0.005). Children who had received PCV were at lower risk of vaccine-type carriage (2.9% vs 0.8%; P=0.005). Conclusions Between 2014 and 2019, the proportion of children carrying serotype 23A increased significantly, while the carriage rate of NTHi decreased. Continuous surveillance is needed to assess the long-term effects of the PCVs on carriage dynamics of pneumococcus and NTHi.

Antithymocyte globulin (ATG) and anti-T lymphocyte globulin (ATLG) have been widely used to prevent graft-versus-host disease (GvHD), each with distinct properties and noninterchangeable doses. However, the optimal dose of ATG in children undergoing allo-PBSCT for leukemia has not yet been established. Therefore, the impact of ATG dose on overall survival (OS), relapse, GvHD, and infectious complications was investigated. Patients administered high dose (unrelated: 7.5 mg/kg, haploidentical: 10.0 mg/kg) and low dose (unrelated: 3.75 mg/kg, haploidentical: 5.0 mg/kg) ATG during two consecutive time periods were compared. There were 78 (39.8%) patients in the low dose group and 118 (60.2%) in the high dose group. OS was superior in the low dose group compared to the high dose group (P = 0.017), and relapse incidence was significantly lower in the low dose group (P = 0.022). Cumulative incidences of acute and chronic GvHD were similar between the groups (P = 0.095 and P = 0.672, respectively). Cytomegalovirus reactivation (70.3% vs. 51.3%, P = 0.007), Epstein-Barr virus reactivation (81.4% vs. 39.7%, P < 0.001), and invasive bacterial infections (12.7% vs. 0%, P = 0.001) post transplant were more frequent in the high dose group compared to the low dose group. Therefore, low dose ATG is more optimal in pediatric allo-PBSCT providing better OS while lowering the risk of relapse and infectious complications.

Background: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment.Purpose: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children.Methods: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006–2016. Electronic medical records were analyzed and radiologic images were evaluated.Results: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0–10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0–2 months, 2.1:1 for those 3–5 months, and 1.6:1 for those 6–11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (PPP=0.03).Conclusion: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

Objectives To investigate the genetic characteristics associated with eradication failure of Staphylococcus aureus in infants below 90 days old. Methods S. aureus isolated from clinical specimen cultures (blood, surgical tissue, or drainage, pus, etc.) and routine screening cultures in the neonatal intensive care unit (nasal and axillary skin swab) from patients below 90 days old were collected prospectively for 1 year, from August 2017 to July 2018. The isolates underwent typing and screening for genes associated with chlorhexidine (qacA/B), quaternary ammonium (smr), and mupirocin resistance (iles mutation, mupA, mupB), as well as Panton-Valentine leukocidin (PVL) toxin. Results During the study period, 40 nonduplicate isolates were included for analyses, of which 70.0% were methicillin-resistant S. aureus (MRSA). Mupirocin resistance was found in 25% of the total isolates; 17.4% of the colonizers; and 35.3% of the pathogens (P = 0.196). Chlorhexidine resistance gene was found in 3 MRSA isolates colonized in the nares of preterm infants. All isolates harbored the disinfectant quaternary ammonium compound (QAC) resistance gene. PVL toxin gene was found in 57.5%, and the presence of PVL gene among colonizers and pathogens was similar (69.6% vs. 41.2%, P = 0.072). Conclusions Mupirocin, chlorhexidine, and QAC-resistant MRSAs harboring the PVL toxin gene were found in the nasal carriages of preterm infants. In this highly vulnerable patient population, one-fourth of the isolates harbored mupirocin-resistant genes, and all were resistant to QAC disinfectants. These strains are associated with persistence in both carriage and environmental reservoirs within the hospitals.

After primary infection, varicella zoster virus (VZV) causes prolonged latent infections that may reactivate, depending on the immunologic status of the host. We present a case of VZV reactivation in a 10-year-old male patient that underwent unrelated peripheral blood stem cell transplantation (uPBSCT) for T-lymphoblastic lymphoma with lymphoma cutis lesions. This patient had a history of herpes zoster involving the right L2-5 dermatome and trigeminal V1 dermatome prior to uPBSCT. Three months post-uPBSCT, the patient’s underlying disease relapsed, and the patient presented with lymphoma cutis lesions. A few days after a skin biopsy was performed to pathologically confirm skin relapse, vesicles appeared only involving the skin areas with lymphoma cutis. This case illustrates how decreased areas of epidermal immune mechanisms may cause atypical presentations of varicella infection.

Septicemia or bacteremia is one of the leading causes of death worldwide. Long-term tunneled central venous catheters (CVCs) are usually placed in children undergoing chemotherapy or hematopoietic stem cell transplantation (HSCT) for underlying hemato–oncologic malignancies. However, catheter-related complications have been reported frequently, and there is high morbidity and mortality related to catheter-line-associated bloodstream infections (CLABSIs). We report a rare case of six episodes of recurrent K. pneumoniae sepsis within a 6-month period in a 12-year-old male adolescent that underwent HSCT for acute lymphoblastic leukemia, despite treatment with susceptible antibiotics. The patient received extensive diagnostic evaluations to find the hidden source; however, failure to discover the primary source led to multiple recurrences. Through enterobacterial repetitive intergenic consensus (ERIC)-PCR, we were able to identify the relationship between the six episodes and recognize the source of bacteremia.

Cytomegalovirus (CMV) reactivation in allogeneic hematopoietic stem cell transplantation (allo-HSCT) causes significant morbidity and mortality. This study aimed to investigate the clinical characteristics of children diagnosed with CMV GI disease after allo-HSCT. This was a retrospective cohort study of patients19 years old that underwent allo-HSCT during an 11-year period. Of the 756 patients, 55.5% (n = 420) experienced post-transplant CMV DNAemia, 2.9% (n = 22) were diagnosed with proven CMV GI diseases, and the highest incidence was found in familial mismatched donors (5.6%, P = 0.029). CMV GI disease was diagnosed100 days of transplant in 68.2% (n = 15/22), and 13.6% (n = 3/22) did not have concurrent CMV DNAemia. Patients were divided into five groups based on the patterns of CMV viremia initiation and duration post-HSCT. At 3 months post-transplant, lower CD4+ (P = 0.006) and CD8+ (P = 0.011) T-cell counts were observed in patients with waxing and waning CMV viral load titers100 days post-transplant (groups 1-3) compared to those with CMV DNAemia only prior to 100 days post-transplant and those without concurrent CMV DNAemia (groups 4-5). A higher 1-year all-cause mortality was observed in groups 1-3 compared to groups 4-5 (42.8% vs. 0%; P = 0.051). Active surveillance and aggressive management of CMV reactivation is crucial, especially in children with delayed CD4+ and CD8+ T-cell reconstitution after allo-HSCT.

The aim of the present study is to re-evaluate the clinical application of two-times serologic immunoglobulin M (IgM) tests using microparticle agglutination assay (MAA), an enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) assay in diagnosing Mycoplasma pneumoniae (MP) infection. A retrospective analysis of 62 children with MP pneumonia during a recent epidemic (2019–2020) was conducted. The MAA and ELISA immunoglobulin M (IgM) and IgG measurements were conducted twice at admission and around discharge, and MP PCR once at presentation. Diagnostic rates in each test were calculated at presentation and at discharge. The seroconverters were 39% (24/62) of patients tested by MAA and 29% (18/62) by ELISA. At presentation, the diagnostic positive rates of MAA, ELISA, and PCR tests were 61%, 71%, and 52%, respectively. After the second examination, the rates were 100% in both serologic tests. There were positive correlations between the titers of MAA and the IgM values of ELISA. The single serologic IgM or PCR tests had limitations to select patients infected with MP in the early stage. The short-term, paired IgM serologic tests during hospitalization can reduce patient-selection bias in MP infection studies.

Background The risk of weight gain as a consequence of school closure in children during the coronavirus disease-2019 (COVID-19) pandemic has been recognized. This study was performed to investigate changes in anthropometric and metabolic parameters in children following a 6-month period of social distancing and school closure due to the pandemic. Methods This retrospective cohort study was conducted in school-aged children that were on routine follow-up at the Growth Clinic of Seoul St. Mary's Hospital. Changes in body mass index (BMI) standard deviation scores (z-scores), lipid profiles, and vitamin D levels were investigated. The 1-year period prior to school closure was defined as “pre-COVID-19 period,” and the subsequent 6-month period as “COVID-19 period.” Results Overall, 226 children between 4 to 14 years old without comorbidities were assessed. On average, their BMI z-scores increased by 0.219 (95% confidence interval [CI], 0.167–0.271; P < 0.001) in the COVID-19 period compared to the pre-COVID-19 period, and the proportion of overweight or obesity increased from 23.9% in the pre-COVID-19 period to 31.4% in the COVID-19 period. The number of days after school closure (P = 0.004) and being in the normoweight category in the pre-COVID-19 period (P = 0.017) were factors associated with an increased BMI in the COVID-19 period. The mean triglyceride (105.8 mg/dL vs. 88.6 mg/dL, P < 0.001) and low-density lipoprotein-cholesterol (100.2 mg/dL vs. 94.0 mg/dL, P = 0.002) levels were higher, whereas the calcidiol level (18.9 mg/dL vs. 23.8 mg/dL, P < 0.001) was lower in the COVID-19 period compared to the pre-COVID-19 period. Conclusion Within 6 months, increased childhood obesity and vitamin D deficiencies were observed. The duration of school closure was significantly associated with an increased BMI and being normoweight does not exclude the risks for gaining weight., Graphical Abstract

Monitoring regional antibiotic resistance patterns of uropathogens are important for deciding suitable empirical antibiotics for urinary tract infections (UTIs) in children. This study aimed to investigate regional differences in antimicrobial susceptibility patterns of E. coli and Klebsiella spp. in children below 24 months old, diagnosed with their first episode of UTI, and to find factors associated with an increased risk for UTI caused by extended-spectrum &beta, lactamase (ESBL)-producing uropathogens. This was a retrospective cohort study of children diagnosed between 2011 and 2017 in four different hospitals located in four different regions of South Korea, regions A, B, C, and D. The government&rsquo, s big data repository was used to acquire data on regional antibiotic prescriptions. The pooled antimicrobial susceptibilities of E. coli and Klebsiella spp. (n = 2044) were as follows: ampicillin&ndash, sulbactam (61.0%), 3rd generation cephalosporin (3C) (82.8%), and trimethoprim&ndash, sulfamethoxazole (72.0%). Multivariate analysis showed that children diagnosed at hospital A (OR, 1.8, 95% confidence interval [CI], 1.2&ndash, 2.6, P = 0.002) and every year that increased in the study period (OR, 1.1, 95% CI, 1.1&ndash, 1.2, P &lt, 0.001) were factors associated with an increased risk for UTIs with ESBL-producers. Regions A and B had significantly higher amounts of oral 3Cs prescribed compared to regions C and D (P = 0.009), which correlate with hospitals in the regions that had higher proportions of UTIs with ESBL-producing uropathogens (A and B vs. C and D, P &lt, 0.001). Therefore, children in certain regions are at a higher risk for UTIs caused by ESBL-producers compared to other regions, which correlate with regions that had higher amounts of oral 3Cs prescribed.

Purpose This study aimed to analyse laboratory values according to fever duration, and evaluate the relationship across these values during the acute phase of Kawasaki disease (KD) to aid in the early diagnosis for early-presenting KD and incomplete KD patients. Methods Clinical and laboratory data of patients with KD (n=615) were evaluated according to duration of fever at presentation, and were compared between patients with and without coronary artery lesions (CALs). For evaluation of the relationships across laboratory indices, patients with a fever duration of 5 days or 6 days were used (n=204). Results The mean fever duration was 6.6±2.3 days, and the proportions of patients with CALs was 19.3% (n=114). C-reactive proteins (CRPs) and neutrophil differential values were highest and hemoglobin, albumin, and lymphocyte differential values were lowest in the 6-day group. Patients with CALs had longer total fever duration, higher CRP and neutrophil differential values and lower hemoglobin and albumin values compared to patients without CALs. CRP, albumin, neutrophil differential, and hemoglobin values at the peak inflammation stage of KD showed positive or negative correlations each other. Conclusion The severity of systemic inflammation in KD was reflected in the laboratory values including CRP, neutrophil differential, albumin, and hemoglobin. Observing changes in these laboratory parameters by repeated examinations prior to the peak of inflammation in acute KD may aid in diagnosis of early-presenting KD patients.

Antibiotics’ effect on Mycoplasma pneumoniae (MP) infection still remains controversial. A prospective study of 257 children with MP pneumonia during a recent epidemic (2015-2016) was conducted. All MP pneumonia patients were treated with corticosteroids within 24-36 h after admission. Initially, oral prednisolone (1 mg/kg) or intravenous methylprednisolone (IVMP) (1-2 mg/kg) was administered for mild pneumonia patients, and IVMP (5 -10 mg/kg/day) for severe pneumonia patients. If patients showed persistent fever for 36-48 hours or disease progression, additive IVMP (5 mg/kg or 10 mg/kg) was given. Eighty-five patients received only a broad-spectrum antibiotic without macrolide. The mean age and the male:female ratio were 5.6 ± 3.1 years, respectively. Seventy-four percent of patients (190/257) showed immediate defervescence within 24 h, and 95.7% (246/257) of patients showed defervescence within 72 h with improvements in clinical symptoms. Eight patients who received additive IVMP also showed clinical improvement within 48 h without adverse reactions. There were no clinical or laboratory differences between patients treated with a macrolide (n = 172) and without (n = 85). Early corticosteroid therapy might reduce disease morbidity and prevent disease progression in MP pneumonia patients without side effects, and antibiotics may have limited effects on MP infection.

Antibiotics&rsquo, effect on Mycoplasma pneumoniae (MP) infection still remains controversial. A prospective study of 257 children with MP pneumonia during a recent epidemic (2015&ndash, 2016) was conducted. All MP pneumonia patients were treated with corticosteroids within 24&ndash, 36 h after admission. Initially, oral prednisolone (1 mg/kg) or intravenous methylprednisolone (IVMP, 1&ndash, 2 mg/kg) was administered for mild pneumonia patients, and IVMP (5&ndash, 10 mg/kg/day) for severe pneumonia patients. If patients showed a persistent fever for 36&ndash, 48 h or disease progression, additive IVMP (5 mg/kg or 10 mg/kg) was given. Thirty-three percent of patients received only a broad-spectrum antibiotic without a macrolide. The mean age and the male-to-female ratio was 5.6 &plusmn, 3.1 years and 1:1, respectively. Seventy-four percent of patients showed immediate defervescence within 24 h, and 96% of patients showed defervescence within 72 h with improvements in clinical symptoms. Three percent of patients (8/257) who received additive IVMP also showed clinical improvement within 48 h without adverse reactions. There were no clinical or laboratory differences between patients treated with a macrolide (n = 172) and without (n = 85). Early corticosteroid therapy might reduce disease morbidity and prevent disease progression in MP pneumonia patients without side effects, and antibiotics may have limited effects on MP infection.

It is unknown whether epidemiological or clinical characteristics of Henoch-Schönlein purpura (HSP) have changed over time. This study aimed at evaluating the epidemiological and clinical changes of HSP during 3 decades.We retrospectively analyzed the data of 515 children with HSP (0-15 years of age) between 1987 and 2015. We compared the two HSP patient groups: those admitted from 1987 to 1996 (group A, 238 cases) and those admitted from 2006 to 2015 (group B, 98 cases), apart a decade.In total 515 patients, the mean age was 6.5 ± 3.0 years and the male-to-female ratio was 1.2:1 (278:237). The age distribution showed a peak at age 5 with a bell-shaped distribution pattern. The annual number of cases varied in each year with a trend of reduced cases in the recent decade. There were less cases during the summer season. Purpura, gastrointestinal involvement, joint involvement, and renal involvement were found in 100%, 56%, 38%, and 18% of the patients, respectively. In comparison between the two groups, there were similar findings in mean age, age distribution, and seasonal distribution. However, the hospitalization stay was longer, and the proportion of recurrent cases (14 cases vs. 0 case) and proteinuria (15% vs. 3%) were higher in the group A than in the group B.Long-term epidemiologic features of HSP were similar to those in other countries. Clinical manifestations of HSP showed a trend towards a less severe clinical phenotype over time in Deajeon, Korea. Key Points • It is unknown whether epidemiological and clinical traits of Henoch-Schönlein purpura (HSP) have changed over time. • We reported that clinical manifestations of HSP have changed to milder phenotype through a long-term observation of three decades at a single hospital in Daejeon, South Korea. • Clinical phenotype of infection-related diseases, including HSP, may be changed over time, and the etiology and the reason of clinical changes over time remain to be solved.

Conventional methods for etiologic diagnoses of acute gastroenteritis (AGE) are time consuming and have low positive yield leading to limited clinical value. This study aimed to investigate quality improvements in patient management, antibiotic stewardship, and in-hospital infection transmission prevention using BioFire® FilmArray® Gastrointestinal Panel (GI Panel) in children with acute diarrhea. This was a prospective study recruiting children &lt, 19 years old with new onset diarrhea during the study period, and a matched historical cohort study of children diagnosed with AGE during the 4 years prior. Patients in the prospective cohort underwent stool testing with GI Panel and conventional methods. A total of 182 patients were included in the prospective cohort, of which 85.7% (n = 156) had community-onset and 14.3% (n = 26) had hospital-onset diarrhea. A higher pathogen positivity rate for community-onset diarrhea was observed by the GI Panel (58.3%, n = 91) compared to conventional studies (42.3%, n = 66) (p = 0.005) and historical cohort (31.4%, n = 49) (p &lt, 0.001). The stool tests reporting time after admission was 25 (interquartile range, IQR 17–46) hours for the GI Panel, and 72 (IQR 48–96) hours for the historical cohort (p &lt, 0.001). A significant reduction in antibiotic use was observed in the prospective cohort compared to historical cohort, 35.3% vs. 71.8%, p &lt, 0.001), respectively. Compared to the GI Panel, norovirus ICT was only able to detect 4/11 (36.4%) patients with hospital-onset and 14/27 (51.8%) patients with community-onset diarrhea. The high positivity rate and rapid reporting time of the GI Panel had clinical benefits for children admitted for acute diarrhea, especially by reducing antibiotic use and enabling early adequate infection precaution and isolation.

2021년 3월 현재, 인류는 2019년 말부터 시작된 코로나바이러스 감염증-19(COVID-19)의 세계적 유행으로 인해 고통받고 있다. 2020년에는 messenger RNA (mRNA) 백신, 바이러스 벡터를 사용한 DNA 백신 등 새로운 플랫폼의 백신들이 긴급사용 승인을 받았고, 이후 대규모 접종이 이루어지기 시작하였다. 본 논문에서는 현재 전 세계적으로 가장 널리 사용되고 있는 COVID-19 백신들에 대하여 그 기전을 살펴보고, 임상시험 내용을 분석하여 효능과 안전선에 대한 자료를 정리하였고, 소아 청소년에 대한 백신 임상시험 상황 및 소아에서 고려할 점에 대하여 언급하였다.

The current design code for building structures in South Korea specifies the minimum fire resistance ratings and fire-resisting performances for each structural component, for which a standard fire curve is required to be applied. There are, however, obvious differences between the standard fire curve and the actual fire behaviour observed from real events. In this study, a fire dynamic-based simulation was conducted on a typical underground parking structure, from which a realistic fire design curve was obtained. In addition, thermal behaviour and fire-resisting response of hollow-core slabs in the underground parking structure were estimated by using the realistic fire design curve, which was compared to those based on the design fire curve specified in the current code. On this basis, it is considered that more rational and economic fire resistance design of underground parking structure is possible by utilizing the realistic fire curve.

Spondylodiscitis (SD) is a rare disease in children and diagnosis can be delayed because of the scarcity in incidence and lack of awareness. The purpose of this study was to evaluate and report the microbiologic epidemiology and clinical features of pediatric SD in South Korea.This was a retrospective study of children19 years old admitted for the treatment of SD between 2000 and 2014. Electronic medical records were reviewed for clinical parameters and etiologic agents.During the 15-year period, 25 patients were diagnosed with SD. The median age was 13.8 years, and 60% were male. Back pain was the most common presenting symptom (n = 17; 68%), and only 52% (n = 13) of the patients had a history of fever (≥38.0°C). In patients younger than 3 years, irritability (n = 5; 62.5%) was the most predominant symptom. Microorganisms were isolated in 22 cases, the most common being Staphylococcus aureus (40%) and Mycobacterium tuberculosis (32%). Of the 25 patients, 64% (n = 16) had blood cultures taken, 56% (n = 14) underwent percutaneous fluoroscopy-guided biopsy, and 48% (n = 12) underwent open surgical biopsy. The positive rate for microbiologic diagnosis of each method was 18.8% (n = 3) for blood culture, 71.4% (n = 10) for percutaneous biopsy and 100% (n = 12) for surgical biopsy. Overall, 52% (n = 13) needed surgical treatment along with antibiotic therapy. Patients who needed surgery had a significant delay in diagnosis compared with those that did not (median, 60 vs. 31 days; P = 0.014).S. aureus and M. tuberculosis are the predominant causes of SD in children in South Korea. Obtaining tissue culture is important to confirm the bacterial etiology of the infection and appropriately guide antibiotic therapy in a community in which the endemic organisms require treatment pathways that are widely divergent.

Background: Kawasaki disease (KD) may be associated with infection of unknown pathogen(s). For predicting of the etiology of KD, we evaluated epidemiological characteristics in KD, common infectious diseases and immune-mediated diseases in childhood. Methods: We respectively, reviewed the data of patients with KD, influenza, aseptic meningitis, exanthem subitum (ES), Mycoplasma pneumoniae (MP) pneumonia, acute pyelonephritis (APN), Henoch-Schonlein purpura (HSP), acute poststreptococcal glomerulonephritis (APSGN), and childhood asthma. We compared and interpreted epidemiological data across the groups. Results: In age distribution, KD, APN, and ES showed a similar pattern in that majority of patients were infants or young children, and other diseases showed a relatively even age-distribution which had a peak age, mainly 5-6 years, with bell-shape patterns. In annual-case pattern, there were epidemic years in aseptic meningitis and MP pneumonia, and the fluctuated annual cases were seen in other diseases. The trends of decreasing cases were seen in APSGN, HSP, and childhood asthma in recent years. In seasonal frequency, influenza or aseptic meningitis occurred in mainly winter or summer season, respectively. HSP and APSGN cases had less in summer, and KD, APN, and ES showed relatively even occurrence throughout a year without significant seasonal variations. Conclusions: Our results suggest that KD agents may be associated with normal flora that are influenced by environmental changes, since pathogens of APN and ES could be regarded as normal flora that originate from the host itself or ubiquitously existing human reservoirs.

Voriconazole is an antifungal drug used to treat fungal infections. This was a retrospective study of 61 children with hemato-oncologic diseases or solid organ transplantation who were administered voriconazole for invasive fungal infections. Of the 61 patients, 31 (50.8%) were in the therapeutic drug monitoring (TDM) group, and 30 (49.2%) were in the non-TDM group. At 12 weeks, treatment failure rate in the non-TDM group was higher than the TDM group (78.6% versus 40.0%, p = 0.038). Drug discontinuation due to adverse events was less frequent in the TDM group than the non-TDM group (26.0% versus 92.3%, p = 0.001). Children required higher dosages to maintain drug levels within the targeted therapeutic range: an average of 8.3 mg/kg/dose in patients

In this study, to assess the fire performances of corrugated webbed prestressed (CWPS) composite beams exposed to fire, full-scale fire resisting tests were carried out, and fire-resisting behavioural responses of the test specimens were analyzed and compared with those obtained from nonlinear finite element analyses. Key test variables were the cover thickness of the fire protection material applied to the bottom flange of corrugated webbed steel beams, which was directly exposed to fire, and the shapes of corrugated webs. All the composite beams with fire protection material covers exposed to standard fire showed good fire-resisting capacities with fire ratings over 3 h and in particular, CWPS composite beams with relatively thin fire protection material cover thickness, compared with the non-prestressed slim-floor composite beam, satisfied the required fire performance criteria in ISO 834 standard and Eurocode. Additionally, the test results showed that the shape of corrugated webs used in CWPS composite beam specimens could have a great impact on their fire-resisting performance. The nonlinear finite element analyses performed in this study accurately estimated the overall behaviours of test specimens and especially assessed the effects of the shape of the corrugated web on the temperature distributions and fire resistance performances of CWPS composite beams appropriately.

Susceptibility to infection varies by species, and asymptomatic birds could be carriers., In January 2014, an outbreak of infection with highly pathogenic avian influenza (HPAI) A(H5N8) virus began on a duck farm in South Korea and spread to other poultry farms nearby. During this outbreak, many sick or dead wild birds were found around habitats frequented by migratory birds. To determine the causes of death, we examined 771 wild bird carcasses and identified HPAI A(H5N8) virus in 167. Gross and histologic lesions were observed in pancreas, lung, brain, and kidney of Baikal teals, bean geese, and whooper swans but not mallard ducks. Such lesions are consistent with lethal HPAI A(H5N8) virus infection. However, some HPAI-positive birds had died of gunshot wounds, peritonitis, or agrochemical poisoning rather than virus infection. These findings suggest that susceptibility to HPAI A(H5N8) virus varies among species of migratory birds and that asymptomatic migratory birds could be carriers of this virus.

In this study, the structural performance of prestressed composite girders with corrugated webs was evaluated by conducting experiments on a total of five specimens with the key test variables of prestress level, tendon layout patterns, welding methods, and shear connectors. The test results showed that flexural performances of the prestressed composite girders were superior to the non-prestressed specimen. Partial interaction analyses were also performed on the test specimens to investigate the horizontal shear transfer mechanisms between steel girder and concrete, and their results were discussed in detail.

AIMS Measured glomerular filtration rate (mGFR) is often used to identify augmented renal clearance (ARC). However, in the clinical setting, estimated GFR (eGFR) is obtained more quickly and inexpensively. We aimed to determine whether eGFR can identify ARC by evaluating the correlation between the eGFR and vancomycin trough level (VTL). MATERIALS AND METHODS We retrospectively reviewed the records of patients aged ≤ 18 years who underwent vancomycin therapeutic drug monitoring at our tertiary hospital from July 2009 to June 2014. VTL, serum creatinine concentration, eGFR, and clinical factors affecting VTL were analyzed. RESULTS Of 101 patients, 76 (75.25%) had a subtherapeutic VTL. Patient age (p = 0.006), the daily vancomycin dose (p = 0.041) and dosing interval (p = 0.006), and eGFR (p

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.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 reaction amplification to detect the presence of the hypervirulent GBS adhesin (hvgA) gene. Antibiotic susceptibility testing was done by E-test, and erythromycin resistance genes were detected using polymerase chain reaction amplification.Among 98 GBS isolates collected, 14 sequence types (STs) were found; ST1 (20.4%), ST17 (19.4%) and ST19 (18.4%) were the most prevalent. The dominant serotype capsule expressed by ST1 was serotype V, ST17 and ST19 were all serotype III and ST23 was serotype Ia. hvgA gene was detected in 19.4% (n = 19) of the isolates; all were ST17, serotype III. A significant temporal trend of serotype III isolates was observed; as ST17 increased (P = 0.001) in proportion, ST19 decreased (P = 0.009). Erythromycin resistance was found in 42.9% (42/98); dominant strains were ermB-positive ST1 serotype V (n = 18/20, 90%), ermB-positive ST17 serotype III (n = 10/19, 52.6%) and ermA-positive ST335 serotype III (n = 7/7, 100%).The predominant STs causing invasive infections in South Korea were ST1, ST19 and ST17. Among serotype III isolates, an increase in proportion of the hypervirulent ST17 strains was observed. Erythromycin resistance was significantly associated with ST1.

Background Increasing prevalence of mupirocin-resistant Staphylococcus aureus have been reported, and chlorhexidine resistance has become an issue. This study aimed to investigate the prevalence of mupirocin and chlorhexidine resistance in both colonized and infection causing Staphylococcus aureus in children, and find factors associated with increased virulence. Methods Staphylococcus aureus, isolated from children Results During the study period, a total of 49 non-duplicate isolates were included, of which 69.4% (n = 34) were Methicillin-resistant Staphylococcus aureus (MRSA). Of the colonizers (n = 25), the most common sequence type was ST 72 (68.0%), whereas among pathogens (n = 24), ST 72 (29.2%) and ST 89 (29.2%) were most prevalent. Pathogens in this study caused abscess formation (n = 3), sepsis (n = 4), and skin infections such as cellulitis and omphalitis (n = 17). Mupirocin resistance was found in 16.0% among colonizers vs. 45.8% among pathogens (P = 0.023). High-level mupirocin resistance was more common (n = 3/25, 12.0%) than low-level mupirocin resistance (n = 1/25, 4.0%) in colonizers, whereas, pathogens had similar rates of low-level (25.0%) and high-level (n = 20.8%) mupirocin resistance. PVL toxin gene was more frequently found in colonizers than pathogens (64.0% vs. 33.3%, P = 0.032), and all isolates had quaternary ammonium resistance genes. Chlorhexidine resistance gene was found in only 3 MRSA isolates colonized in the nares of preterm infants. All were SCCmec type 4, however, two were ST 72, spa type t1054, which had high -level mupirocin resistance and PVL toxin gene. Conclusion A PVL toxin gene-positive MRSA which had genes causing mupirocin and chlorhexidine resistance were found in the nasal carriages of preterm infants. These stains may cause failure of MRSA eradication in hospital settings, using conventional methods of nasal mupirocin application and chlorhexidine bathing. Disclosures All authors: No reported disclosures.

Background Ascending infections are thought as the main route of infection in acute pyelonephritis (APN). However, among patients diagnosed with APN, a subset has atypical presentation unexplainable by ascending routes of infections. This study aimed to review 8 cases initially diagnosed as APN, however presenting with no or minimal pyuria and presenting as acute focal bacterial nephritis (AFBN). Methods This was a retrospective cohort study of children Results During the 11-year period, of the total of 359 patients were diagnosed with the first episode of APN. Of these, 8 were re-diagnosed as AFBN. The mean age was 9.8 years old (1.9–17.4). Abdominal pain with nausea and vomiting were chief complaints (62.5%), and none had urinary symptoms including dysuria, incontinence, or increased frequency. Initial urinalysis in all the patients showed WBC Conclusion Lack of urinary symptoms, insignificant pyuria, and CT findings of AFBN support the possibility of an alternative route of infection, other than the ascending route. Disclosures All authors: No reported disclosures.

ObjectiveThis study was aimed to evaluate epidemiological and clinical relationship betweenMycoplasma pneumoniae(MP) infection and childhood recurrent wheezing episode (RWE).DesignRetrospective case note review.SettingPaediatric department at a single Korean institution.ParticipantsConsecutive admitted patients with MP pneumonia and RWE (0–15 years of age) between 2003 and 2014.MethodsThe retrospective medical records of patients with (MP) pneumonia (n=793 for epidemiological analysis and n=501 for clinical analysis) and those with RWE (n=384) from 2003 to 2014 were analysed. Diagnosis of MP pneumonia was made based on two-times titration of IgM antibody during hospitalisation. An RWE patient was defined as one with expiratory wheezing with at least one or more wheezing episodes based on medical records.ResultsDuring three MP pneumonia epidemics, there were no corresponding increases of patients with RWE in the epidemic years. In the 501 MP pneumonia patients, 52 (10.4%) had wheezing at presentation and 15 (3%) had RWE. The MP pneumonia patients with wheezing at presentation (n=52) were younger and were more likely to have an allergic disease history than those without wheezing (n=449). Among wheezing patients at presentation, 10 patients had previously RWE history. In a follow-up study, 13 patients (including 5 RWE) with initial wheezing and 25 patients (including 2 RWE) without wheezing had wheezy episodes after discharge. Among the total 501 patients, it was estimated that at least 31 MP pneumonia patients (6.2%) showed recurrent wheezing after initial MP infection.ConclusionsA small part of children with MP pneumonia showed recurrent wheezing after MP pneumonia, and patients with RWE had a greater likelihood of experiencing wheezing when they had an initial MP infection. However, there were no increased admitted patients with RWE in MP pneumonia epidemic periods because of rarity of MP reinfection in children including patients with RWE or asthma.

목적: 본 연구에서는 신생아실과 신생아 중환자실에서 발생한 methicillin-resistant Staphylococcus aureus (MRSA) 유행에서 환자와 보균자에서 분리된 MRSA의 분자역학적 연관성을 조사하여 유행의 감염원과 전파경로를 파악하고자 하였다. 방법: MRSA 유행기간인 2017년 8월부터 9월까지 피부감염 및 패혈증 환자들과 보균자로부터 분리된 MRSA 균주를 대상으로 유전형 및 병원성 인자를 분석하고 항생제 감수성 결과를 수집하였다. 결과: 연구기간 동안 신생아실(n=27)과 신생아 중환자실(n=14)에 총 41명의 신생아들이 입원하였다. 그 중, 7명(피부감염[n=6], 패혈증[n=1])에서 MRSA 감염이 확진되었고, 보균자 4명이 발견되었다. 신생아와 접촉이 있는 의료진 32명 중 3명이 MRSA를 비강에 보균하였다. 피부감염 유행 원인 균주는 Staphylococcal chromosomal cassette mec (SCCmec) type II, se quence type (ST) 89, spa type t375였고, 뮤피로신 저농도 내성을 포함하여 항생제 다제내성을 보였다. 패혈증을 일으킨 균주는 SCCmec type IVa, ST 72, 새로운 spa type인 t17879였다. 신생아 4명에게 집락된 MRSA 균주들은 다양하였으나 SCCmec type IVa, ST 72, spa type t664가 의료진과 신생아 2명에서 공통적으로 분리되었다. Panton-Valentine leukocidin (PVL) toxin 유전자가 신생아에게 집락된 모든 균주에서 발견되었다. 결론: 피부감염 유행을 일으킨 MRSA 균주는 항생제 다제내성을 보이는 균주였다. 신생아 MRSA 보균자에게서 분리된 균주는 모두 PVL 독소 유전자를 보유하였다. 유행기간 동안 다양한 MRSA 균주가 신생아들에게서 분리되기 때문에, 효과적인 감염 관리 및 추가 환자발생의 차단을 위하여 분자역학조사를 통하여 원인균을 확인하고 전파경로를 파악하는 것이 중요하다.

BACKGROUND The purpose of this study was to compare the outcome of carbapenem versus non-carbapenem antimicrobial therapy for pediatric urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae. MATERIALS AND METHODS From 2006 to 2011, 42 episodes of UTI caused by ESBL-producing Enterobacteriaceae were diagnosed at Seoul National University Children's Hospital. Patients were grouped according to the antimicrobials they received into a carbapenem group and a non-carbapenem group. Medical records were retrospectively reviewed to assess treatment outcome, time to defervescence after initiation of treatment, and relapse rate. RESULTS There were 36 children with 42 episodes of UTI caused by ESBL-producing Enterobacteriaceae. Twenty-seven cases (64%) had an underlying urologic disease, 28 (67%) cases were caused by Escherichia coli, and 14 (33%) cases were caused by Klebsiella pneumoniae. Four (10%) cases were treated with carbapenem, 23 cases (55%) were treated with non-carbapenem, and 15 (36%) cases were treated by switching from a carbapenem to a non-carbapenem and vice versa. There was no treatment failure at the time of antimicrobial discontinuation. Between the carbapenem and the non-carbapenem treatment groups, there were no significant differences in bacterial etiology (P = 0.59), time to defervescence after the initiation of antimicrobials (P = 0.28), and relapse rate (P = 0.50). In vitro susceptibility to non-carbapenem antimicrobials did not affect the time to defervescence after the initiation of antimicrobial treatment, and the relapse rate in the non-carbapenem group. CONCLUSIONS This study found no significant difference in the treatment outcome between pediatric patients treated with carbapenem and those treated with non-carbapenem antimicrobials for UTI caused by ESBL-producing Enterobacteriaceae. Therefore, the initially administered non-carbapenem can be maintained in UTI patients showing clinical improvement.

From the avian influenza virus (AIV) outbreaks and market surveillances in Vietnam during November 2011 and March 2012, a total of 196 AIV were isolated. Although H5N1 highly pathogenic avian influenza (HPAI) was the most prevalent subtype in Vietnam, 57 low pathogenic avian influenza (LPAI) viruses were identified from mainly domestic ducks and some chickens. Of note, various subtypes of LPAI viruses were isolated from domestic ducks in Vietnam: H3 (n = 16), H4 (n = 4), H6 (n = 24), H7 (n = 1), and H9 (n = 10). Geographically, the LPAI viruses were identified in different regions of Vietnam. Phylogenetic analysis of HA and NA genes in LPAIV in Vietnam showed that some H3 (group I) and H4 subtypes AIV clustered with the viruses of several Asian isolates from domestic poultry and wild birds. However, the H6, H9, and some H3 (group II and III) subtypes AIV were closely related to isolates from domestic poultry in Southern China. In addition, whereas the N2 and N6 subtypes AIV belonged to the Eurasian lineage, the N8 subtype AIV was classified to be both of Eurasian and American lineage. These findings revealed that the regional trade and wild birds play a key role transmission of LPAIV in domestic ducks in Vietnam. Further surveillance at the intercountry level is needed to understand the epidemiology of these viruses and to cope with emergence of novel AIV types.

Background National surveillance of avian influenza virus (AIV) in South Korea has been annually conducted for the early detection of AIV and responses to the introduction of highly pathogenic avian influenza (HPAI) virus. In this study, we report on a nationwide surveillance study of AIV in domestic poultry and wild birds in South Korea between 2012 and 2014. Methods During the surveillance programs between 2012 and 2014, 141,560 samples were collected. Of these, 102,199 were from poultry farms, 8215 were from LBMs, and 31,146 were from wild bird habitats. The virus isolation was performed by inoculation of embryonated chicken eggs and AIV isolates were detected using hemagglutination assay. For subtying of AIV, the hemagglutinin and neuraminidase genes were confirmed by sequencing. Phylogenetic analysis of the H5 subtypes was performed using 28 H5 AIV isolates. Results Between 2012 and 2014, a total of 819 AIV were isolated from 141,560 samples. Virus isolation rates for AIV were 0.6, 0.4, 0.1, and 2.7% in wild birds (n = 202), domestic ducks (n = 387), minor poultry (n = 11), and the live bird market (LBM) (n = 219), respectively. In wild birds, various subtypes were found including H1–H7 and H9–H13. The major subtypes were H5 (n = 48, 23.9%: N3 (n = 4) and N8 (n = 44)), H4 (n = 39, 19.4%), and H1 (n = 29, 14.4%). In domestic poultry, mainly ducks, the H5N8 (n = 275, 59.3%), H3 (n = 30, 17.2%), and H6 (n = 53, 11.4%) subtypes were predominantly found. The most frequently detected subtypes in LBM, primarily Korean native chicken, were H9 (n = 169, 77.2%). H3 (n = 10, 4%) and H6 (n = 30, 13.7%) were also isolated in LBM. Overall, the prevalence of AIV was found to be higher between winter and spring and in western parts of South Korea. The unusual high prevalence of the H5 subtype of AIV was due to the large scale outbreak of H5N8 HPAI in wild birds and domestic poultry in 2014. Conclusions Enhanced surveillance and application of effective control measures in wild birds and domestic poultry, including LBM, should be implemented to control AI and eradicate HPAI. Electronic supplementary material The online version of this article (doi:10.1186/s12985-017-0711-y) contains supplementary material, which is available to authorized users.

Since the first outbreak of low pathogenic avian influenza (LPAI) in 1996, outbreaks of LPAI have become more common in Korea, leading to the development of a nationwide mass vaccination program in 2007. In the case of highly pathogenic avian influenza (HPAI), four outbreaks took place in 2003-04, 2006-07, 2008, and 2010-11; a fifth outbreak began in 2014 and was ongoing at the time of this writing. The length of the four previous outbreaks varied, ranging from 42 days (2008) to 139 days (2010-11). The number of cases reported by farmers that were subsequently confirmed as HPAI also varied, from seven cases in 2006-07 to 53 in 2010-11. The number of farms affected by the outbreaks varied, from a low of 286 (2006-07) with depopulation of 6,473,000 birds, to a high of 1500 farms (2008) with depopulation of 10,200,000 birds. Government compensation for bird depopulation ranged from $253 million to $683 million in the five outbreaks. Despite the damage caused by the five HPAI outbreaks, efficient control strategies have yet to be established. Meanwhile, the situation in the field worsens. Analysis of the five HPAI outbreaks revealed horizontal farm-to-farm transmission as the main factor effecting major economic losses. However, horizontal transmission could not be efficiently prevented because of insufficient transparency within the poultry industry, especially within the duck industry, which is reluctant to report suspicious cases early. Moreover, the experiences and expertise garnered in previous outbreaks has yet to be effectively applied to the management of new outbreaks. Considering the magnitude of the economic damage caused by avian influenza and the increasing likelihood of its endemicity, careful and quantitative analysis of outbreaks and the establishment of control policies are urgently needed.

This study was performed to assess the serotype distribution and antibiotic nonsusceptibility of pneumococcal carriage isolates from children in Korea following the introduction of extended-valency pneumococcal conjugate vaccines (PCVs).From April to June 2014, nasopharyngeal swabs were collected from children who were attending daycare centers in Korea. The collection was conducted in accordance with the World Health Organization Pneumococcal Carriage Working Group standards. Isolates were identified based on colony morphology, the presence of alpha-hemolysis, and inhibition by optochin test. Serotype was determined by Quellung reaction and sequencing analysis (for serogroup 6). The E-test was performed to determine antibiotic susceptibility.A total of 267 pneumococcal isolates were collected from 734 children. Non-PCV13 serotypes accounted for 88.3% and 23A (12.6%), 15B (10.4%), and 15C (9.5%) were most common. Younger age was associated with higher carriage (65.6% vs. 31.2%, P0.001), while completion of PCV vaccination was associated with lower carriage caused by PCV13 serotypes (7.4% vs. 20.8%, P=0.007). Overall, nonsusceptibility rates were 86.0% to penicillin and 90.5% to erythromycin, with a multidrug resistance rate of 81.5%. Among penicillin-nonsusceptible isolates, those caused by PCV13 serotypes were 11% and non-PCV13 serotypes were 89%. Frequent non-PCV13 serotypes (23A, 15B, and 15C) were all nonsusceptible to both penicillin and erythromycin except one.High rates of carriage caused by non-PCV13 serotypes such as 23A, 15B, and 15C that show nonsusceptibilities to penicillin and erythromycin were noted following the introduction of extended-valency PCVs in Korea.

The purpose of this study is to develop a valid and reliable infant observation scale based on the national curriculum for childcare centers. The study was carried out using the final draft of the Infant Observation Scale for 1 year old infants. The scale consists of 42 items in 6 areas. Whereas the final draft of the Infant Observation Scale for 2 year old infants consists of 52 items in 6 areas. The subjects of this observation scale were 120 infants from the city of Busan. The results of the Infant Observation Scale for the 1 year old infant analysis for the purpose of test adequacy indecates that the internal consistency reliability is from .88 to .97. The results of the Infant Observation Scale for 2 year old infant analysis for test adequacy shows that the internal consistency reliability is from .76 to .97.

Background Acinetobacter baumannii (AB) invasive infections are known to have a worse clinical outcome than non-baumannii Acinetobacter infections. However, currently, phenotypic identification by semi-automated commercial identification systems struggle to distinguish Acinetobacter subspecies; especially the four closely related subspecies of the Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex. The purpose of this study was to examine the rate of misidentification of AB isolated from invasive infections in children. Methods From January 2001 to December 2017, patients 18 years old and below who were treated for invasive AB infections at Seoul National University Hospital and Chungnam National University Hospital were included. Acinetobacter baumannii, identified by commercial identification systems, cultured from sterile body fluids of the study participants were prospectively collected. The DNA from the stored bacteria were isolated, and subspecies identification was carried out by PCR and sequencing of the partial gyrB gene. Clinical data were retrospectively reviewed. Results During the 17-year study period, 113 AB isolates were obtained from patients treated for invasive infections. The median age of the patients was 2 (IQR 0–7) years old and 47 (49.5%) were male. Duplicate isolates were eliminated, and a total 95 isolates underwent further investigation. The isolates were retrieved from the blood (n = 82), peritoneal fluid (n = 8), pleural fluid (n = 2), cerebrospinal fluid (n = 2), and bronchoalveolar fluid (n = 1). Of the AB isolates identified by the commercial identification systems, 55 (57.9%) were AB. Of the non-AB isolates identified by partial gyrB sequencing, 22 (23.2%) were identified as A. nosocomialis, 8 (8.4%) as A. pittii, and 1 (1.1%) as A. calcoaceticus. Non-ACB complex subspecies included A. soli (n = 3), A. seifertii (n = 3), A. iwoffii (n = 1), A. bereziniae (n = 1), and A. junnii (n = 1). Conclusion There was a high rate of misidentification of the Acinetobacter subspecies causing invasive infections in children. Further studies are needed to analyze the burden that misidentification has on the treatment and outcome of patients with invasive infections. Disclosures H. Lee, Korean Society of Pediatric Infectious Diseases: Member, Research grant.

In 2014, an H5N8 outbreak of highly pathogenic avian influenza (HPAI) occurred in South Korea. The H5N8 strain produced mild to moderate clinical signs and mortality rates in commercial chicken farms, especially Korean native chicken farms. To understand the differences between their pathogenicity in SPF chicken and Korean native chicken., we evaluated the mean bird lethal doses (BLD50) of the Korean representative H5N8 virus (A/broiler duck/Korea/Buan2/2014) The BLD50values of the H5N8 virus were 10(5.3)EID50 and 10(6.7)EID50 in SPF and Korean native chickens, respectively. In addition, the mean death time was much longer, and the viral titers in tissues of H5N8-infected chickens were significantly lower, in the Korean group than in the SPF group. These features of the H5N8 virus likely account for its mild-to-moderate pathogenicity in commercial chicken farms, especially Korean native chicken flocks, despite the fact that it is a highly pathogenic virus according to the OIE criteria. To improve current understanding and management of HPAI, pathogenic characterization of novel emerging viruses should be performed by natural route in major poultry species in each country.

Objectives To analyze the clinical characteristics of children with Kikuchi-Fujimoto disease focusing on cases with prolonged fever. Study design This was a retrospective study of children diagnosed with Kikuchi-Fujimoto disease from March 2003 to February 2015 in South Korea. Electronic medical records were searched for clinical and laboratory manifestations. Results Among 86 histopathologically confirmed cases, the mean age was 13.2 (SD ± 3.1) years, and male to female ratio was 1:1.32. Cervical lymph node enlargement, found in 85 of the patients (99%), was predominantly unilateral in 64 (75%), and involved the cervical lymph node level V in 67 (81%). Fever was present in 76% of the cases, with a median duration of 9 days (IQR 0.25-17.0). Multivariate analysis revealed that a high fever peak ≥39.0°C ( P = .010) and presentation with ≥2 systemic symptoms other than fever ( P = .027) were factors that were significantly associated with longer fever duration. As the size of the largest lymph node's short diameter increased, the fever duration increased ( P = .015). Leukopenia ( P = .022) also had a significant association with a longer fever duration. Patients with sonographic findings of conglomerated enlarged lymph nodes had a longer median duration of fever compared with those with separate enlarged lymph nodes (11 vs 4.5 days, P = .019). Conclusions Patients with high fever, more systemic symptoms, leukopenia, and larger lymph nodes with a conglomerated distribution may benefit from early recognition and selective consideration of corticosteroid therapy.

The corrugated webbed prestressed (CWPS) composite member was developed to improve the efficiency of the prestress introduced into the steel beam, and experimental studies were performed to examine its structural behavior. Additionally, a unified analysis model that can estimate the nonlinear flexural behavior of the composite member and the accordion effect of the corrugated webbed steel beams at the prestressing stage was proposed. As a consecutive experimental series, in this study, the discontinuous-webbed prestressed (DWPS) composite member was developed, and this innovative composite member can reduce the amount of steel materials used, compared with the former CWPS composite member. Flexural tests were carried out to investigate their structural performances, and their behaviors were analyzed in detail by a nonlinear finite element analysis.

Highly pathogenic H5N8 avian influenza viruses (HPAIVs) were introduced into South Korea during 2014, thereby caused outbreaks in wild birds and poultry farms. During the 2014 outbreak, H5N8 HPAIVs were isolated from 38 wild birds and 200 poultry farms (up to May 8, 2014). To better understand the introduction of these viruses and their relationships with wild birds and poultry farm, we analyzed the genetic sequences and available epidemiological data related to the viruses. Genetic analysis of 37 viruses isolated from wild birds and poultry farms showed that all of the isolates belonged to clade 2.3.4.6 of the hemagglutinin (HA) gene, but comprised two distinct groups. During the initial stage of the outbreak, identical isolates from each group were found in wild birds and poultry farms near Donglim Reservoir, which is a resting site for migratory birds, thereby indicating that two types of H5N8 HPAIVs were introduced into the lake at the same time. Interestingly, the one group of H5N8 HPAIV predominated around Donglim Reservoir, and the predominant virus was dispersed by wild birds among the migratory bird habitats in the western region of South Korea as time passed, and it was also detected in nearby poultry farms. Furthermore, compared with the results of the annual AIV surveillance of captured wild birds, which has been performed since 2008, more HPAIVs were isolated and H5 sero-prevalence was also detected during the 2014 outbreak. Overall, our results strongly suggest that migratory birds played a key role in the introduction and spread of viruses during the initial stage of the 2014 outbreak.

Aortic regurgitation is a serious complication of Behcet's disease. We report a 17-year-old male with severe aortic regurgitation caused by Behcet's disease. An early diagnosis led to the immediate start of immunosuppressants followed by successful valvuloplasty with autologous pericardium.

Staphylococcus aureus is one of the main etiological agents of bovine mastitis; however, antibiotics that are effective against bovine strains of S. aureus are not currently available. Staphylococcal enterotoxin type C (SEC), a superantigen, is the enterotoxin most frequently expressed by bovine strains of S. aureus and one of immunogenic determinants. The purpose of this study was to evaluate the protective effectiveness of recombinant SEC mutant vaccine (MastaVactrade mark) against experimentally induced bovine infection. Three representative SEC secreting strains were selected from 9 candidate isolates that showed various intensities of pathogenicity on mice and inoculated into 5 lactating dairy cattle at a concentration of 50-5.0x10(8) CFU per quarter. The optimal experimental bovine subclinical mastitis model was produced by inoculation with 50 CFU of S. aureus 409 per quarter, a level which was not lethal to mice. After the experimental model was determined, other 3 cattle were intramuscularly administered three doses of vaccine at day 0, at 2 wks and at 6 wks. Nine quarters of 3 vaccinated cattle and 8 quarters of 3 control cattle were then challenged with S. aureus 409. An SEC-specific ELISA test conducted at 4 wks post-immunization confirmed the presence of a high antibody titer against SEC in all vaccinated cattle. The somatic cell counts from the vaccinated group remained relatively low, whereas those of control group increased significantly after challenge with S. aureus. After challenge, S. aureus was not isolated from any cattle in the vaccinated group, whereas it was isolated from 75% of the cattle in the control group. These results indicate that recombinant SEC mutant vaccine had a protective effect against S. aureus intramammary infection in lactating cattle.

Summary Background The prognosis of lung cancer is still poor, since there are few early detection tools available yet. So, it is important to identify more efficient and clinically applicable biomarkers associated with the prognosis in as earlier stages as possible. Patients and methods In this study, we observed the expression of CD63 in 90 cases of non-small cell lung cancer (NSCLC) to explore the potential of this molecule as a prognostic biomarker for lung cancer subtypes using real-time quantitative RT-PCR and tissue microarray based immunohistochemistry. Results Majority of NSCLCs (75.8%) showed lower CD63 RNA level (less than half) than normal tissue. Notably, all SqCs showed low-expression except one case, while AdCs showed diverse range of expression. CD63 protein expression level was largely compatible with RNA level. Totally, 63.3% of NSCLC were CD63 protein expression negative. All SqCs were negative, while majority (70.2%) of adenocarcinomas (AdCs) were positive. CD63 protein negativity was significantly associated with SqCs type, larger tumor size, and advanced stage. In AdCs, CD63 negativity was associated with poor survival ( p =0.008). This association was also significant in earlier stage (I and II) AdCs ( p =0.041), but not in advanced stage AdCs. After being adjusted for age and sex by Cox regression and stratified by stages, CD63 negativity still showed borderline association with poor survival as an independent predictor ( p =0.076, HR=2.3). Conclusions Taken together, these results suggest that CD63 can be a biomarker for predicting the prognosis in earlier stage of lung AdCs. Our findings can be a clue to investigate the role of CD63 in tumorigenesis of AdCs of lung and other cancers.