Complete mitochondrial genome of Acanthochitona defilippii (Polyplacophora: Chitonida) from South Korea.

The chiton (Polyplacophora) occupies a significant position in molluscan evolutionary history as one of the most primitive groups within the phylum Mollusca. Acanthochitona defilippii (Tapparone-Canefri 1874) (Chitonida: Acanthochitonidae) is a commonly found intertidal chiton species in South Korea. In this study, we characterized the complete mitochondrial genome of A. defilippii (14,999 bp long), comprising 13 protein-coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and an A + T rich region (166 bp). The base composition is as follows: 31.82% for A, 11.63% for C, 16.69% for G, and 39.86% for T. We reconstructed a maximum likelihood (ML) tree to elucidate phylogenetic relationships among the eight chitonid families using the nucleotide sequences of all PCGs. The ML tree revealed that A. defilippii clustered with Acanthochitona avicula (BP 100) within the family Acanthochitonidae. Acanthochitonidae formed a sister group with Mopaliidae. The results could provide a valuable understanding the phylogenetic relationships of chitonid species.

Epidemiology of Respiratory Viruses in Korean Children Before and After the COVID-19 Pandemic: A Prospective Study From National Surveillance System.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic. METHODS: A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017-2019) and postpandemic (2021-2023) periods. RESULTS: A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023. The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023. CONCLUSION: With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Pediatric Deaths Associated With Coronavirus Disease 2019 (COVID-19) in Korea.

As of September 3, 2022, 5,388,338 coronavirus disease 2019 (COVID-19) cases and 46 deaths (3 in 2021 and 43 in 2022) were reported in children ≤ 18 years in Korea. Cumulative confirmed cases accounted for 67.3% of the population aged ≤ 18 years and case fatality rate was 0.85/100,000. Among 46 fatal cases, 58.7% were male and median age was 7 years. Underlying diseases were present in 47.8%; neurologic diseases (63.6%) and malignancy (13.6%) most common. Only four had history of COVID-19 immunization. COVID-19 associated deaths occurred at median 2 days from diagnosis (range: -1 to 21). Among COVID-19 deaths, 41.3% occurred before admission; 2 before hospital arrival and 17 in the emergency department. Among children whose cause was documented, myocarditis, respiratory and multiorgan failure were most common. COVID-19 associated death was seen early after diagnosis in children and public health policies to provide access to medical care for children with COVID-19 are essential during the pandemic.

Threshold of Quantitative Cytomegalovirus DNA PCR for Preemptive Treatment in Pediatric Hematopoietic Stem Cell Transplant Recipients.

BACKGROUND: Consensus cytomegalovirus (CMV) DNA viral load thresholds for intervention in hematopoietic stem cell transplant (HSCT) recipients have not been established, especially in children. This study aimed at obtaining viral load thresholds of CMV DNA to guide preemptive management in pediatric HSCT recipients. MATERIALS AND METHODS: A total of 465 blood samples from 177 children who received HSCT between 2015 and 2019 were included in a single center in Korea. The samples were analyzed for CMV infection by both antigenemia assay and quantitative DNA polymerase chain reaction. The 2 assay results were compared for the 233 samples which were collected when antiviral treatment has not been initiated. We determined the viral loads corresponding to the antigenemia of 5 pp65-positive cells/2×10 5 white blood cells (WBCs) as the level for initiating preemptive therapy. RESULTS: Sixty percent of the samples were collected within 100 days (39.7% in 0 to 50 d, 60.2% in 0 to 100 d) from the graft infusion. The correlation between CMV DNA viral load and CMV antigenemia level increased significantly after 50 days from the graft infusion ( r =0.71 vs. r =0.93, P <0.0001). The correlation was greater in the antiviral treatment-naive group than the treatment group ( r =0.75 vs. r =0.66, P <0.0001). Under receiver operating characteristic curve analysis of the treatment-naive group, the estimated threshold CMV DNA viral loads corresponding to 5 pp65-positive cells/2×10 5 WBCs was 898 IU/mL. CONCLUSIONS: The CMV DNA levels that corresponded to 5 pp65-positive cells/2×10 5 WBCs was 900 IU/mL in the HSCT group. The proposed viral load thresholds can be used to guide preemptive therapy in pediatric HSCT recipients, especially in the preengraftment period.

Outbreak of COVID-19 among children and young adults in a cancer centre daycare unit.

Nosocomial transmission of COVID-19 among immunocompromised hosts can have a serious impact on COVID-19 severity, underlying disease progression and SARS-CoV-2 transmission to other patients and healthcare workers within hospitals. We experienced a nosocomial outbreak of COVID-19 in the setting of a daycare unit for paediatric and young adult cancer patients. Between 9 and 18 November 2020, 473 individuals (181 patients, 247 caregivers/siblings and 45 staff members) were exposed to the index case, who was a nursing staff. Among them, three patients and four caregivers were infected. Two 5-year-old cancer patients with COVID-19 were not severely ill, but a 25-year-old cancer patient showed prolonged shedding of SARS-CoV-2 RNA for at least 12 weeks, which probably infected his mother at home approximately 7-8 weeks after the initial diagnosis. Except for this case, no secondary transmission was observed from the confirmed cases in either the hospital or the community. To conclude, in the day care setting of immunocompromised children and young adults, the rate of in-hospital transmission of SARS-CoV-2 was 1.6% when applying the stringent policy of infection prevention and control, including universal mask application and rapid and extensive contact investigation. Severely immunocompromised children/young adults with COVID-19 would have to be carefully managed after the mandatory isolation period while keeping the possibility of prolonged shedding of live virus in mind.

Changes in the incidence of invasive disease due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis during the COVID-19 pandemic in 26 countries and territories in the Invasive Respiratory Infection Surveillance Initiative: a prospective analysis of surveillance data

Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, which are typically transmitted via respiratory droplets, are leading causes of invasive diseases, including bacteraemic pneumonia and meningitis, and of secondary infections subsequent to post-viral respiratory disease. The aim of this study was to investigate the incidence of invasive disease due to these pathogens during the early months of the COVID-19 pandemic. Methods In this prospective analysis of surveillance data, laboratories in 26 countries and territories across six continents submitted data on cases of invasive disease due to S pneumoniae, H influenzae, and N meningitidis from Jan 1, 2018, to May, 31, 2020, as part of the Invasive Respiratory Infection Surveillance (IRIS) Initiative. Numbers of weekly cases in 2020 were compared with corresponding data for 2018 and 2019. Data for invasive disease due to Streptococcus agalactiae, a non-respiratory pathogen, were collected from nine laboratories for comparison. The stringency of COVID-19 containment measures was quantified using the Oxford COVID-19 Government Response Tracker. Changes in population movements were assessed using Google COVID-19 Community Mobility Reports. Interrupted time-series modelling quantified changes in the incidence of invasive disease due to S pneumoniae, H influenzae, and N meningitidis in 2020 relative to when containment measures were imposed. Findings 27 laboratories from 26 countries and territories submitted data to the IRIS Initiative for S pneumoniae (62 434 total cases), 24 laboratories from 24 countries submitted data for H influenzae (7796 total cases), and 21 laboratories from 21 countries submitted data for N meningitidis (5877 total cases). All countries and territories had experienced a significant and sustained reduction in invasive diseases due to S pneumoniae, H influenzae, and N meningitidis in early 2020 (Jan 1 to May 31, 2020), coinciding with the introduction of COVID-19 containment measures in each country. By contrast, no significant changes in the incidence of invasive S agalactiae infections were observed. Similar trends were observed across most countries and territories despite differing stringency in COVID-19 control policies. The incidence of reported S pneumoniae infections decreased by 68% at 4 weeks (incidence rate ratio 0·32 [95% CI 0·27­0·37]) and 82% at 8 weeks (0·18 [0·14­0·23]) following the week in which significant changes in population movements were recorded. Interpretation The introduction of COVID-19 containment policies and public information campaigns likely reduced transmission of S pneumoniae, H influenzae, and N meningitidis, leading to a significant reduction in life-threatening invasive diseases in many countries worldwide. Funding Wellcome Trust (UK), Robert Koch Institute (Germany), Federal Ministry of Health (Germany), Pfizer, Merck, Health Protection Surveillance Centre (Ireland), SpID-Net project (Ireland), European Centre for Disease Prevention and Control (European Union), Horizon 2020 (European Commission), Ministry of Health (Poland), National Programme of Antibiotic Protection (Poland), Ministry of Science and Higher Education (Poland), Agencia de Salut Pública de Catalunya (Spain), Sant Joan de Deu Foundation (Spain), Knut and Alice Wallenberg Foundation (Sweden), Swedish Research Council (Sweden), Region Stockholm (Sweden), Federal Office of Public Health of Switzerland (Switzerland), and French Public Health Agency (France).

The complete mitochondrial genome of a whiter-spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae).

The complete mitochondrial genome of Protaetia brevitarsis, an important Scarabaeidae insect that is distributed across most Asian countries, was characterized using long template PCR methods. It was 17,783 bp in length being composed of 13 protein coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a non-coding region. The phylogenetic tree reconstructed based on the maximum likelihood (ML) method confirmed that P. brevitarsis was placed within the clade of Scarabaeidae and Polyphaga species forming a complete monophyly.

Effective and Rapid Microbial Identification in Pediatric Osteoarticular Infections Using Blood Culture Bottles.

BACKGROUND: The detection and identification of pathogenic microorganisms are essential for the treatment of osteoarticular infection. However, obtaining a sufficient amount of specimen from pediatric patients is often difficult. Herein, we aimed to demonstrate the effectiveness of the blood culture bottle (BCB) system in pediatric osteoarticular infections. We hypothesized that our BCB culture method is superior to the conventional swab and tissue culture methods in terms of required specimen size, incubation time, and microbial identification rate. METHODS: We analyzed the prospectively collected data of pediatric patients who underwent surgical treatment for osteoarticular infections between August 2016 and October 2019. Four needles were dipped in the infected fluid or tissue during the surgical procedure as soon as the infected area was exposed and were used to inoculate 2 aerobic pediatric BCBs and 2 anaerobic general BCBs. We also collected 2 conventional swab samples and 2 tissue samples from the identical area. The microbial identification rate and the time required for identification were compared between BCB, swab, and tissue cultures. RESULTS: Forty patients constituted the study group; 13 patients had osteomyelitis, 17 patients had septic arthritis, and 10 patients had both. Of these 40 patients, the microbial identification rate was higher with BCB cultures (27 [68%]) than with swab cultures (18 [45%]; p = 0.004) or tissue cultures (15 [38%]; p < 0.001). Nine samples (9 patients [23%]) were only positive in the BCB culture. Positive microbial growth was not detected with conventional culture methods when microorganisms did not grow on the BCB culture. Compared with swab culture (4.3 ± 1.1 days; p < 0.001) or tissue culture (4.4 ± 1.1 days; p < 0.001), the BCB culture reduced the time required for microbial identification (3.5 ± 0.9 days). CONCLUSIONS: In pediatric osteoarticular infections, the BCB culture system improved the microbial identification rate, reduced the time to identification, and permitted a smaller-volume specimen, compared with traditional culture systems. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Financial Burden of Hospitalization of Children with Coronavirus Disease 2019 under the National Health Insurance Service in Korea.

Coronavirus disease 2019 (COVID-19) has resulted in an ongoing pandemic; however, the socioeconomic burden of COVID-19 treatment in the pediatric population remains unclear. Thus, the aim of this study was to determine the hospitalization periods and medical costs among children with COVID-19. In total, 145 billing statements for pediatric patients receiving healthcare services because of COVID-19 from February 1, 2020 to March 31, 2020 were used. The study showed that individual treatment costs for children with COVID-19 are approximately USD 2,192 under the Korean National Health Insurance Service System. This study revealed the differences in cost among age groups, determined by the type of hospital wherein admission occurred, as a trend of increasing age, increasing hospitalization time, and increasing cost was observed. Tailored COVID-19 treatment strategies by age group may lower costs and increase the effectiveness of resource allocation.

Molecular epidemiology of respiratory syncytial virus for 28 consecutive seasons (1990-2018) and genetic variability of the duplication region in the G gene of genotypes ON1 and BA in South Korea.

We investigated the molecular epidemiology of respiratory syncytial virus (RSV) isolated from children during 28 consecutive seasons (1990-2018) and the genetic variability of the duplication region of RSV genotypes ON1 and BA in South Korea. RSV was identified using culture-based methods in Hep-2 cells and was grouped as RSV-A or RSV-B by an immunofluorescence assay. The second hypervariable region of the G gene was sequenced for genotyping. The nucleotide and deduced amino acid sequences of the duplication region of RSV ON1 and BA were analyzed. A total of 670 RSV-A and 233 RSV-B isolates were obtained. For RSV-A, the NA1 genotype predominated during the 2004/2005-2011/2012 seasons. The ON1 genotype was first detected in 2011 and has since replaced all other genotypes. For RSV-B, the GB3 genotype predominated during the 1999/2000-2005/2006 seasons, but the BA genotype also replaced all other genotypes of RSV-B after the first season in which it was isolated (2005/2006). In ON1 and BA genotype RSV strains, novel sequence types of the duplication region of the G gene were identified in 50-95% and 33-80% of the isolates, respectively, in each season. The ON1 and BA9 genotypes are responsible for the current epidemics of RSV infection in South Korea. The sequences in the duplication region of the G gene have evolved continuously and might be sufficient for the identification of specific strains of the RSV-A ON1 and RSV-B BA genotypes.

Cytomegalovirus disease in a retinoblastoma cohort: The role of preemptive screening.

BACKGROUND: Cytomegalovirus (CMV) disease is underrecognized in children with retinoblastoma. This study investigated rates of CMV infection and disease in this specific population receiving chemotherapy. METHODS: From a cohort of 164 patients with retinoblastoma diagnosed from 2011 to 2018, 107 patients were evaluated for CMV infection determined by antigenemia assay or real-time PCR. Preemptive CMV screening was implemented in 2013. CMV disease was diagnosed by tissue biopsy, culture, or ophthalmic examination. RESULTS: Thirty-seven and 70 patients before and after the screening strategy, respectively, were included. Before screening, 10/37 (27%) were diagnosed with CMV infection during chemotherapy. Among them, 5 (50%) developed CMV disease (hepatitis, pneumonia, and retinitis) and one patient died of CMV pneumonia. During screening, 18/70 (26%) were documented with 36 episodes of CMV infection and 9 patients received 25 preemptive antiviral therapies. Age at chemotherapy tended to be younger in patients with CMV infection, and fewer were seronegative prior to chemotherapy. Patients who started chemotherapy at <12 months of age received preemptive therapies significantly more often than those started at ≥12 months. Two (11%) out of 18 patients with CMV infection developed CMV retinitis and colitis, and there were no fatal cases. Preemptive therapy along with active CMV screening significantly reduced the risk of developing CMV disease, from 14% to 2.9% (P = 0.047). CONCLUSIONS: Children with retinoblastoma can experience significant morbidity and even mortality from CMV infection during chemotherapy in Korea. Preemptive screening and appropriate antiviral therapy can reduce the development of CMV disease and subsequent mortality.

A homobifunctional imidoester-based microfluidic system for simultaneous DNA and protein isolation from solid or liquid biopsy samples.

The isolation of bio-molecules such as proteins and nucleic acids is a necessary step for both diagnostic and analytical processes in the broad fields of research and clinical applications. Although a myriad of isolation technologies have been developed, a method for simultaneous protein and nucleic acid isolation has not been explored for clinical use. Obtaining samples from certain cancers or rare diseases can be difficult. In addition, the heterogeneity of cancer tissues typically leads to inconsistent results when analyzing biomolecules. We here describe a homobifunctional imidoester (HI)-based microfluidic system for simultaneous DNA and protein isolation from either a solid or liquid single biopsy sample. An efficient and cost effective microfluidic design with less air bubbles was identified among several candidates using simulation and experimental results from the streamlining of isolation processing. HI groups were used as capture reagents for the simultaneous isolation of bio-molecules from a single specimen in a single microfluidic system. The clinical utility of this system for the simultaneous isolation of DNA and proteins within 40 min was validated in cancer cell lines and 23 tissue biopsies from colorectal cancer patients. The quantity of isolated protein and DNA was high using this system compared to the spin-column method. This HI-based microfluidic system shows good rapidity, affordability, and portability in the isolation of bio-molecules from limited samples for subsequent clinical analysis.

Recommended immunization schedule for children and adolescents: Committee on Infectious Diseases of the Korean Pediatric Society, 2018.

The Committee on Infectious Diseases of the Korean Pediatric Society recommended immunization schedule for children and adolescents aged 18 years or younger in the 9th (2018) edition of Immunization guideline. This report provides the revised recommendations made by the committee and summarizes several changes from the 2015 guideline. National immunization program (NIP) launched a human papillomavirus (HPV) immunization for girls aged 12 years in 2016. NIP has also expanded age indication for inactivated influenza vaccine (IIV) to 12 years of age in the 2018-2019 season. Quadrivalent IIVs with a full dose (0.5 mL) are approved for all children of 6 months or older. Recommendations of live attenuated influenza vaccine were removed. For inactivated Japanese encephalitis vaccine, first 2 doses are considered as the primary series. Recommendations for use of newly introduced vaccines (diphtheria-tetanus-acellular pertussis/inactivated poliovirus/Haemophilus influenzae type b, 9-valent HPV, new varicella vaccine, new quadrivalent IIV, and attenuated oral typhoid vaccine) were added. Lastly, monitoring system for adverse events following immunization was updated. Other changes can be found in the 9th edition of Immunization guideline in detail.

Risk Factors for Mortality in Children with Acinetobacter baumannii Bacteremia in South Korea: The Role of Carbapenem Resistance.

Aims: Acinetobacter baumannii has become an important nosocomial pathogen that causes invasive infections. We conducted a retrospective study to evaluate the risk factors for mortality due to A. baumannii bacteremia in children. Materials and Methods: We reviewed data from Seoul National University Children's Hospital from 2002 to 2013 for children with A. baumannii bacteremia, including age, gender, underlying disease, associated site of infection, duration of hospitalization, presence of neutropenia, and antibiotic susceptibility data. The outcome measures were the 7- and 30-day mortality rates. Results: Among 74 A. baumannii bacteremia cases, 35.1% were carbapenem nonsusceptible. Common comorbidities were malignancy or hematologic diseases (28.4%), followed by gastrointestinal/hepatobiliary diseases (21.6%). A total of 47.3% of patients had isolated bacteremia, and in 33.8% of patients, pneumonia accompanied bacteremia. The mortality rates were 18.9% at 7 days and 35.1% at 30 days. The significant associated factors for 30-day mortality were carbapenem nonsusceptibility (adjusted hazard ratio [aHR]: 1.28, 95% confidence interval [CI]: 1.10-11.82, p = 0.034), neutropenia (aHR: 1.68, 95% CI: 1.60-18.03, p = 0.007), and prior intensive care unit (ICU) admission (aHR: 1.15, 95% CI: 1.03-9.73, p = 0.045). The mortality rate among neutropenic patients with inappropriate empirical antibiotics was higher than that among patients with appropriate empirical antibiotics (90.1% vs. 33.3%, p = 0.031). Conclusions: We identified carbapenem nonsusceptibility, neutropenia, and prolonged ICU stay as independent risk factors for mortality due to A. baumannii bacteremia in children. An early administration of appropriate antibiotics should be enacted, especially in patients with neutropenia.

Inhibitory effect of Cudratricusxanthone A on osteoclast differentiation and function.

BACKGROUND: Cudratricusxanthone A (CTXA) was isolated from Cudrania tricuspidata and its anti-inflammatory, hepatoprotective, and anti-proliferative activities have previously been studied in vitro. However, effects of CTXA on osteoclast differentiation have not been investigated. PURPOSE: In this study, the effect of CTXA from C. tricuspidata on in vitro osteoclastogenesis was studied. DESIGN/METHODS: CTXA was isolated from the roots of C. tricuspidata. The effects of CTXA on the RANKL-induced osteoclastogenesis, actin ring formation, and bone resorption were tested by using the RAW 264.7 cells and mouse bone marrow monocytes (BMMs). RESULTS: The structure of CTXA was identified by comparison with spectral data in the literature. We also checked the effect of CTXA on in vitro osteoclastogenesis. CTXA significantly inhibited the JNK/MAPK signaling pathway without affecting ERK and p38 signaling in RANKL-stimulated RAW 264.7 cells and BMMs. Moreover, it inhibited RANKL-induced expression of c-Fos and NFATc1. CONCLUSION: In conclusion, CTXA suppresses osteoclast differentiation by inhibiting RANKL-induced MAPK signaling and attenuates bone resorption by disrupting actin ring formation in mature osteoclasts. These results suggest that CTXA inhibits bone resorption through an inhibitory effect on osteoclast formation and function.

Clinical Characteristics and Risk Factors of Long-term Central Venous Catheter-associated Bloodstream Infections in Children.

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 pathogens and the status of CVC placement were collected. Clinical variables were compared between subjects with and without CLABSIs to determine the risk factors for CLABSIs. RESULTS: A total of 629 CVCs were inserted in 499 children during the 5-year period. The median age at insertion was 6.0 years (14 days-17.9 years), and hemato-oncologic disease was the most common underlying condition (n = 497, 79.0%). A total of 235 CLABSI episodes occurred in 155 children, with a rate of 0.93 per 1,000 catheter days. The most common pathogens were Klebsiella pneumoniae (n = 64, 27.2%), coagulase-negative staphylococci (n = 40, 17.0%) and Staphylococcus aureus (n = 28, 12.0%). In the univariate analysis, the gender, underlying disease, catheter characteristics and insertion technique did not increase the risk for CLABSI. In both the univariate and logistic regression analyses, patients with prior BSIs (odds ratio 1.66; 95% confidence interval: 1.090-2.531; P = 0.018) were more likely to have a CLABSI. CONCLUSIONS: CLABSI prevention is of particular concern for children with a prior BSI. Furthermore, the antimicrobial resistance of major pathogens should be monitored to enable the empiric selection of appropriate antibiotics in patients with long-term CVCs.

Radiologic findings as a determinant and no effect of macrolide resistance on clinical course of Mycoplasma pneumoniae pneumonia.

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. Macrolide resistance was determined by the analysis of 23S rRNA gene transition and the minimal inhibitory concentrations of four macrolides. Medical records were reviewed to analyze the clinical response to treatment with macrolides. RESULTS: MP was detected in 116 (4.8%) of the 2436 children with pneumonia. MP pneumonia was prevalent in 2011 and 2015. Of the 116 patients with MP pneumonia, 82 (70.7%) were macrolide-resistant. There were no differences in the age distribution, total duration of fever, and chest x-ray patterns between the macrolide-susceptible and macrolide-resistant groups. After macrolide initiation, mean days to defervescence were longer in the macrolide-resistant group than in macrolide-susceptible group (5.7 days vs. 4.1 days, P = 0.021). However, logistic regression analysis revealed that the presence of extrapulmonary signs (P = 0.039), homogeneous lobar consolidation (P = 0.004), or parapneumonic effusion (P < 0.001) were associated with fever duration of ≥7 days after the initiation of macrolides, regardless of macrolide resistance. CONCLUSIONS: This study demonstrated that fever duration in MP pneumonia was determined by the radiologic findings of chest x-ray, not by the presence of macrolide resistance. The results highlight the need for future studies to assess therapeutic benefit from macrolides in the treatment of children with MP pneumonia.

The Etiology, Clinical Presentation and Long-term Outcome of Spondylodiscitis in Children.

BACKGROUND: 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. METHODS: This was a retrospective study of children <19 years old admitted for the treatment of SD between 2000 and 2014. Electronic medical records were reviewed for clinical parameters and etiologic agents. RESULTS: 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). CONCLUSIONS: 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.

Risk Factors and Clinical Features of Cytomegalovirus Disease in Children Receiving Anticancer Chemotherapy.

This study was conducted to identify risk factors for cytomegalovirus (CMV) infection and demonstrate the spectrum of CMV disease in children receiving anticancer chemotherapy without hematopoietic stem cell transplantation (HSCT). A total of 289 children who received chemotherapy and were tested for CMV infection were included in the study. CMV antigenemia and DNAemia were determined by identifying the pp65 antigen in leukocytes and performing real-time PCR. CMV disease was diagnosed by tissue biopsy, culture, or ophthalmic examination. Of the 289 children, CMV infection was demonstrated in 46 patients (15.9%). Young age at cancer diagnosis was the risk factor for CMV infection by multivariate analysis (7 mo vs. 7 y, P<0.001). Among 46 children with CMV infection, 10 (21.7%) were diagnosed with CMV disease; hepatitis (n=4), retinitis (n=3), hepatitis and pneumonia (n=2), and hepatitis and retinitis (n=1). The age of the patients with CMV disease was significantly younger than those without (3 vs. 16 mo, P=0.023). Retinoblastoma and neuroblastoma were the 2 most common underlying malignancies. There were 2 fatal cases associated with CMV disease, including 1 who died of CMV pneumonia. The findings of this study demonstrated significant morbidity of CMV infection and disease in young children during the course of chemotherapy without HSCT.

The Clinical Significance of Voriconazole Therapeutic Drug Monitoring in Children With Invasive Fungal Infections.

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 <12 years old and 6.9 mg/kg/dose for those ≥12 years old. Treatment failure rates were higher in patients whose voriconazole levels remained below 1.0 mg/L for more than 50% of their treatment duration than those above 1.0 mg/L (71.4% vs. 9.1% after 12 weeks, p = 0.013). Serial monitoring of voriconazole levels in children is important for improving treatment response and preventing unnecessary drug discontinuation. Higher dosages are needed in children to reach therapeutic range.