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Purpose: Streptococcus pyogenes is an important cause of invasive diseases in children. We aimed to describe the clinical characteristics of invasive infections due to S. pyogenes in children in Korea. Methods: A retrospective study of children under 18 years of age with invasive infections due to S. pyogenes at Seoul National University Children's Hospital between March 1992 and December 2012, and Seoul National University Bundang Hospital between March 2003 and December 2012 was conducted. Demographic factors, clinical characteristics, laboratory findings, treatment, mortality and morbidity of all patients were reviewed. Results: A total of 30 among 36 cases identified as invasive disease due to S. pyogenes were available for review. There was a predominance for male subjects (male:female=2.75:1). The median age was 50 months (range 12 days to 15 years) and 53.3% were under 5 years of age. Skin and soft tissue infections (9/30, 30.0%), bacteremia without identified focus (4/30, 13.3%) and bone and joint infections (6/30, 20.0%) were the most frequent clinical presentations. Streptococcal toxic shock syndrome (3/30, 10.0%) pulmonary, abdomen and central nervous system infections (2/30, 6.7%) were also seen. There was a peak in number of patients in year 2012 (9/30, 30.0%). There were no cases of mortality. Erythromycin and clindamycin resistance rates were low by 3.8% and 7.5%, respectively. Conclusion: We studied the clinical presentations of invasive infections due to S. pyogenes during the past 20 years in Korean children. The findings of this study help us understand the characteristics of the disease, enhancing early recognition and prompting adequate antibiotic therapy which is important in reducing morbidity and mortality. [ABSTRACT FROM AUTHOR]

The 7-valent pneumococcal protein conjugate vaccine (PCV7) has been shown to be highly efficacious against invasive pneumococcal diseases and effective against pneumonia and in reducing otitis media. The introduction of PCV7 has resulted in major changes in the epidemiology of pneumococcal diseases. However, pneumococcal vaccines induce serotype-specific immunity, and a relative increase in nonvaccine serotypes has been reported following the widespread use of PCV7, leading to a need for extended serotype coverage for protection. PCV10 and PCV13 have been licensed on the basis of noninferiority of immunogenicity compared to a licensed conjugate vaccine. In this article, we aimed to review important data regarding the efficacy and effectiveness of the extended-coverage PCVs published or reported thus far and to discuss future implications for pneumococcal vaccines in Korea. After the introduction of PCV10 and PCV13, within a short period of time, evidence of protection conferred by these vaccines against invasive and mucosal infections caused by most of the serotypes included in the vaccines is accumulating. The choice of vaccine should be based on the changes in the dynamics of pneumococcal serotype distribution and diseases in the region where the vaccines are to be used. Continuous surveillance is essential for the appropriate use of pneumococcal vaccines and evaluation of the impact of PCVs on pneumococcal diseases. [ABSTRACT FROM AUTHOR]

Purpose: To determine the clinical significance of voriconazole therapeutic drug monitoring (TDM) in the pediatric population. Methods: Twenty-eight patients with invasive fungal infections administered with voriconazole from July 2010 to June 2012 were investigated retrospectively. Fourteen received TDM, and 143 trough concentrations were analyzed. All 28 patients were assessed for adverse events and treatment response six weeks into treatment, and at the end. Results: Out of 143 samples, 53.1% were within therapeutic range (1.0-5.5 mg/L). Patients administered with the same loading (6 mg/kg/dose) and maintenance (4 mg/kg/dose) dosages prior to initial TDM showed highly variable drug levels. Adverse events occurred in 9 of 14 patients (64.3%) in both the TDM and non-TDM group. In the TDM group, voriconazole-related encephalopathy (n=2, 14.3%) and aspartate aminotransferase (AST) or alanine aminotransferase (ALT) elevation (n=8, 57.1 %) occurred with serum levels in the toxic range (>5.5 mg/L), whereas blurred-vision (n=2, 14.3%) occurred within the therapeutic range (1.18 mg/L and 3.9 mg/L). The frequency of voriconazole discontinuation due to adverse events was lower in the TDM group (0.0% vs. 18.2%, P=0.481). Overall, 57.2% of the patients in the TDM group versus 14.3% in the non-TDM group showed clinical response after 6 weeks (P=0.055), whereas 21.4% in the TDM group versus 14.3% in the non-TDM group showed response at final outcome (P=0.664). In the TDM group, >67.0% of the serum levels were within therapeutic range for the first 6 weeks; however 45.5% were within therapeutic range for the entire duration. Conclusion: Routine TDM is recommended for optimizing the therapeutic effects of voriconazole. [ABSTRACT FROM AUTHOR]

Purpose: To identify the clinical and epidemiological characteristics of human metapneumovirus infections (hMPV) in children compared to respiratory syncytial virus A (RSV A) and B (RSV B). Method: A retrospective review of medical records was performed in 36 patients with hMPV infection, 106 with RSV A infection, and 51 with RSV B infection, from September 2007 to July 2012. Results: The peak incidence of hMPV infection was observed in May, whereas for RSV infections in November and December. hMPV infection occurred in older patients compared to RSV A and B infection (29.9±32.5 months vs. 13.6±15.4 months, P<0.001; 29.9±32.5 months vs. 12.1±13.5 months, P<0.001, respectively). hMPV infection was more often associated with fever compared to RSV A (97.2% vs. 67.9%, P<0.001), while wheezing was less frequent compared to RSV A and B infection (16.7% vs. 47.2%, P=0.001; 16.7% vs. 37.3%, P=0.037, respectively). hMPV infection was more often diagnosed as pneumonia compared to RSV A infection (72.2% vs. 50.0%, P=0.047) while bronchiolitis was less frequent than in RSV A (5.6% vs. 34.9%, P=0.001) or RSV B infection (5.6% vs. 29.4%, P=0.006). In addition, intravenous antibiotic was more often prescribed for patients with hMPV infection than those with RSV A and B (69.4% vs. 39.6%, P=0.002; 69.4% vs. 43.1, P=0.015, respectively). Conclusion: This study identified characteristics of hMPV infection compared to RSV A and B infection. Seasonality in spring, higher age group, and higher proportion of pneumonia in hMPV infections may be a useful guide for management of respiratory viral infections in children. [ABSTRACT FROM AUTHOR]

Purpose: This study was performed to describe the clinical manifestations of hospitalized children due to varicella-zoster virus (VZV) infection Methods: This study included 40 children who were hospitalized for varicella or herpes zoster at Seoul National University Children's Hospital, 2009-2012. Diagnosis of VZV infection was confirmed by VZV PCR or culture from vesicular fluid. Medical records were reviewed to collect clinical features and outcome, antiviral treatment, history of varicella vaccination, and underlying diseases. Results: Sixteen patients with varicella and 24 patients with herpes zoster were included. Their median age was 10.5 years (16 days-19 years). Thirty-five (87.5%) patients had underlying diseases. Among 24 patients with herpes zoster, 11 patients had previous history of varicella and 1 had herpes zoster. Twenty patients (50%) had a history of varicella vaccination, and 19 immunocompromised patients had VZV infection despite of vaccination. Most (95%) patients were treated by intravenous or oral acyclovir, and no treatment failure of intravenous acyclovir was found. The median duration of fever was 4.4 days (1-10 days), and that of antiviral treatment was 12 days (7-23 days) in immunocompromised patients. Immunocompromised patients received longer duration of antiviral treatment than imunocompetent patients (P=0.014). Eleven (27.5 %) immunocompromised patients had postherpetic neuralgia, 2 (5%) had proven co-infection by Streptococcus pyogenes and Klebsiella oxytoca, and 1 (2.5%) complicated with pneumonia. Conclusion: Immunocompromised children require longer duration of treatment and are at risk of severe complication associated with VZV infection. Early initiation of antiviral therapy and close monitoring are necessary for those in immunocpom-promised conditions. [ABSTRACT FROM AUTHOR]

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 coil, 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. [ABSTRACT FROM AUTHOR]

In Korea, Mycoplasma pneumoniae was detected in 255/2,089 respiratory specimens collected during 2000-2011; 80 isolates carried 23S rRNA gene mutations, and 69/123 culture-positive samples with the mutation were resistant to 5 macrolides. During 2000-2011, prevalence of the mutation increased substantially. These findings have critical implications for the treatment of children with mycoplasma pneumonia. [ABSTRACT FROM AUTHOR]

The wide use of antimicrobial agents and 7-valent pneumococcal conjugate vaccine (PCV7) has led to major changes in the epidemiology of childhood pneumococcal diseases. In Korea, data on the population-based incidence of childhood invasive pneumococcal diseases (IPD) are not available; however, institution-based surveillance data suggest a substantial burden of childhood IPD. Following the introduction of the PCV7 in Korea in 2003, the proportion of IPD caused by vaccine-type pneumococci has decreased, while non-PCV7 serotypes, especially serotypes 19A and 6A, whose proportions had been increasing before the introduction of the vaccine, became predominant among childhood IPD isolates. This article reviews the overall impact of PCV7 utilization and summarizes the results obtained so far. Continuous monitoring and gathering of scientific evidence for the epidemiological transition of pneumococcal carriage and IPD will be important for the management of pneumococcal infections in Korea. [ABSTRACT FROM AUTHOR]

This article contains the recommended immunization schedule by the Committee on Infectious Diseases of the Korean Pediatric Society, updated in March 2013, when Haemophilus influenzae type b vaccine is now included in the National Immunization Program in Korea. It also includes catchup immunization schedule for children and adolescents who are behind the recommended schedule. These schedules are a minor revision of the corresponding parts of Immunization Guideline, 7th edition, of the Korean Pediatric Society, released in 2012. Pediatricians should be aware of these schedules to provide adequate immunization to Korean children and adolescents [ABSTRACT FROM AUTHOR]

The small notostracan crustacean Triops longicaudatus (LeConte, 1846) is considered a living fossil, with a geological record that reaches back to the Carboniferous Period, and is widespread in North America. This species has been found since 1986 on the Korean Peninsula and was officially designated by the Korean government as an endangered species. No taxonomic survey has yet been performed for the samples of Triops found in Korea. Here, we examined the population genetic structure from 79 individuals of Z longicaudatus throughout the species' geographical range in Korea and to elucidate the phylogenetic relationships among T. longicaudatus-long, T. logicaudatus-short, and T. newberryi, using the nucleotide sequences of CO1 (643 bp) and NDI (444 bp). A total of eight haplotypes in CO1 and nine haplotypes in NDI were found, and 15 haplotypes (HI-HI5) from the combined data of the two genes were also observed. The nested clade analysis and phylogenetic analyses unambiguously corroborate that the Korean populations are subdivided into three distinct genetic lineages. It is highly likely that the Korean populations of T. longicaudatus belong to T. longicaudatus-short. Additionally, T. longicaudatus-long and T. longicaudatus-short may be different, independent species, based on the present phylogeny, the number of legless abdominal rings (LAR), posterior marginal carapace teeth (PMCT), sexual mode, and egg colour. This work is the first comprehensive population genetic and phylogenetic approach for studying T. longicaudatus from East Asia. [ABSTRACT FROM AUTHOR]

Purpose: This study was performed to identify the etiologic agents and antimicrobial susceptibility patterns of organisms responsible for bloodstream infections in pediatric cancer patients for guidance in empiric antimicrobial therapy. Methods: A 5-year retrospective study of pediatric hemato-oncologic patients with bacteremia in Seoul National University Children's Hospital, from 2006 to 2010 was conducted. Results: A total of 246 pathogens were isolated, of which 63.4% (n=156) were gram-negative, bacteria 34.6% (n=85) were gram-positive bacteria, and 2.0% (n=5) were fungi. The most common pathogens were Klebsiella spp. (n=61, 24.8%) followed by Escherichia coli (n=31, 12.6%), coagulase-negative staphylococci (n=23, 9.3%), and Staphylococcus aureus (n=22, 8.9 %). Resistance rates of gram-positive bacteria to penicillin, oxacillin, and vancomycin were 85.7%, 65.9%, and 9.5%, respectively. Resistance rates of gram-negative bacteria to cefotaxime, piperacillin/tazobactam, imipenem, gentamicin, and amikacin were 37.2%, 17.1%, 6.2%, 32.2%, and 13.7%, respectively. Overall fatality rate was 12.7%. Gram-negative bacteremia was more often associated with shock (48.4% vs. 11.9%, P<0.01) and had higher fatality rate than gram-positive bacteremia (12.1% vs. 3.0%, P=0.03). Neutropenic patients were more often associated with shock than non-neutropenic patients (39.6 % vs. 22.0%, P=0.04). Conclusion: This study revealed that gram-negative bacteria were still dominant organisms of bloodstream infections in children with hemato-oncologic diseases, and patients with gram-negative bacteremia showed fatal course more frequently than those with gram-positive bacteremia. [ABSTRACT FROM AUTHOR]

Objectives This study aims to describe the clinical characteristics of enteroviral meningitis in association with the absence of cerebrospinal fluid (CSF) pleocytosis. Design This was a retrospective analysis of databases of patients diagnosed with enteroviral meningitis by CSF reverse transcription-PCR testing. Presence of CSF nonpleocytosis at each age group was analysed by use of the two criteria. Clinical variables were compared with regard to the presence of CSF pleocytosis. Multiple logistic regression analysis was used to identify factors that were associated with CSF pleocytosis. Setting Two hospitals in South Korea, between January 2008 and August 2011. Patients 390 infants and children with enteroviral meningitis. Interventions None. Main outcome measures Proportion of enteroviral meningitis without CSF pleocytosis. Results Among the 390 patients with enteroviral meningitis, 16-18% did not have CSF pleocytosis. In particular, CSF pleocytosis was not present in 68-77% of the neonates with enteroviral meningitis, demonstrating that the proportion of CSF pleocytosis decreased significantly with age ( p<0.001). In multivariate models, younger age (adjusted OR 0.981; 95% CI 0.973 to 0.989), lower peripheral white blood cell count (adjusted OR 0.843; 95% CI 0.791 to 0.899), and shorter interval between onset and lumbar puncture (adjusted OR 0.527; 95% CI 0.315 to 0.882) were associated with the absence of CSF pleocytosis in enteroviral meningitis. Conclusions This study demonstrated high proportion of non-pleocytic enteroviral meningitis in young infants and identified several clinical factors that contributed to the absence of CSF pleocytosis. We suggest that CSF enterovirus PCR testing is likely to detect more cases of enteroviral meningitis, especially in young infants. [ABSTRACT FROM AUTHOR]

The article details the study on the biodiversity of marine invertebrates on rocky shores of Dokdo, Korea. From August 2007 to June 2008, a total of 98 marine invertebrate species were identified. Mollusca and Arthropoda predominated among the 7 phyla that were presented. The relation of the topographical characteristics of each station to the faunal composition and distribution of invertebrates is mentioned. The study concludes that the 403 species, composed of 10 phyla and 172 families, found in Dokdo ecosystem have a high and dynamic biodiversity.

Aims: We investigated the genital group B streptococcus (GBS) carrier rate in Korean pregnant women and the serotype distribution in face of the recent increase of late-onset GBS disease in Korea. Methods: GBS screening was performed on 4045 healthy pregnant women at 35–37 weeks' gestation. In case of positive GBS culture, serotyping was performed by using GBS typing antisera. Results: When both vaginal and anorectal culture were performed, the GBS carrier rate was 10.0% (n=121/1205), which is the highest rate ever reported in Korea. Type III was more common (36%), and type Ia (13%) and Ib (7%) were less prevalent. Conclusions: Increased maternal genital GBS carrier rate and difference in serotype distribution pattern of GBS may be related to the recent increase of late-onset GBS disease in Korea. [ABSTRACT FROM AUTHOR]

Despite the concern of replacement disease, notably by serotype 19A after 7-valent conjugate vaccine (PCV7) use, serotype 19A was increasingly recognized in Korean children before the introduction of PCV7. To understand the dynamics of serogroup 19 prevalence from 1991-2006, we serotyped 538 pediatric pneumococcal isolates. Serogroup 19 isolates (n = 126) were characterized by antimicrobial drug susceptibility, presence of mefA/ermB, and multilocus sequence typing. Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased. Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend). This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use. [ABSTRACT FROM AUTHOR]

Regions (about 3.7-3.8 kb) of the mitochondrial genomes (rrnL-cox1) of two tardigrades, a heterotardigrade, Batillipes pennaki, and a eutardigrade, Pseudobiotus spinifer, were sequenced and characterized. The gene order in Batillipes was rrnL-V-rrnS-Q-I-M-nad2- W-C-Y-cox1, and in Pseudobiotus it was rrnL-V-rrnS-QM- nad2-W-C-Y-cox1. With the exception of the trnI gene, the two tardigrade regions have the same gene content and order. Their gene orders are strikingly similar to that of the chelicerate Limulus polyphemus (rrnL-VrrnS- CR-I-Q-M-nad2-W-C-Y-cox1), which is considered to be ancestral for arthropods. Although the tardigrades do not have a distinct control region (CR) within this segment, the trnI gene in Pseudobiotus is located between rrnL-trnL1 and trnL2-nad1, and the trnI gene in Batillipes is located between trnQ and trnM. In addition, the 106-bp region between trnQ and trnM in Batillipes not only contains two plausible trnI genes with opposite orientations, but also exhibits some CR-like characteristics. The mitochondrial gene arrangements of 183 other protostomes were compared. 60 (52.2%) of the 115 arthropods examined have the M-nad2-W-C-Ycox1 arrangement, and 88 (76.5%) the M-nad2-W arrangement, as found in the tardigrades. In contrast, no such arrangement was seen in the 70 non-arthropod protostomes studied. These are the first non-sequence molecular data that support the close relationship of tardigrades and arthropods. [ABSTRACT FROM AUTHOR]

Although antigenic and genetic variations were shown to occur both in the G and F protein of respiratory syncytial virus (RSV), few studies looked at the variation of F gene. The F genotypes were determined by the evaluation of clustering patterns, via the phylogenetic analysis of the nucleotide sequences of a variable region in the F gene. One hundred seventy‐nine strains obtained from a children's hospital in Korea over nine consecutive epidemics were included. The relationship between the F and G genotypes was analyzed with the G genotypes previously published by the authors. The phylogenetic analysis of the variable region from the F gene revealed 9 genotypes among 129 group A RSVs and 4 genotypes among 50 group B RSVs. In each of the epidemics, the dominant genotypes were replaced with new genotypes in consecutive epidemics. In each of the epidemics of group B RSVs, the predominant genotype alternated between genotypes. Most of the strains which clustered to a particular F genotype were assigned to particular G genotype(s). By determining the nearly entire sequences of the F genes, we revealed the percentage of the nucleotide differences which resulted in amino acid coding changes was determined to be much great in two distinct variable regions of the F gene. Our results indicated that the F gene of the RSVs may be continuously evolving under selective pressure in a distinct pattern, and that the genetic variability of the F protein is associated with that of the G protein. J. Med. Virol. 79: 820–828, 2007. © 2007 Wiley‐Liss, Inc. [ABSTRACT FROM AUTHOR]

Background. This study was performed to evaluate the associations of newly recognized viruses, namely, human metapneumovirus (hMPV), human coronavirus (HCoV)-NL63, and human bocavirus (HBoV) with lower respiratory tract infections (LRTIs) in previously healthy children. Methods. To determine the prevalences of 11 viruses—respiratory syncytial virus (RSV), adenovirus, rhinovirus, parainfluenza viruses (PIVs) 1 and 3, influenza viruses A and B, hMPV, HCoV, HCoV-NL63, and HBoV—among infants or children with LRTIs, in association with their epidemiologic characteristics, we performed multiplex reverse-transcriptase polymerase chain reaction on nasopharyngeal aspirates obtained from 515 children ⩽5 years old with LRTIs during the period 2000–2005. Results. Viruses were identified in 312 (60.6%) of the 515 patients. RSV was detected in 122 (23.7%), HBoV in 58 (11.3%), adenovirus in 35 (6.8%), PIV-3 in 32 (6.2%), rhinovirus in 30 (5.8%), hMPV in 24 (4.7%), influenza A in 24 (4.7%), PIV-1 in 9 (1.7%), influenza B in 9 (1.7%), and HCoV-NL63 in 8 (1.6%). Coinfections with ⩾2 viruses were observed in 36 patients (11.5%). Twenty-two patients (37.9%) infected with HBoV had a coinfection. Bronchiolitis was frequently diagnosed in patients who tested positive for RSV, PIV-3, or rhinovirus, whereas influenza A, PIV-1, and HCoV-NL63 were commonly found in patients with croup. The age distributions of patients with viral infections differed; notably, RSV was responsible for 77% of LRTIs that occurred in infants ⩽3 months old. The number of hMPV infections peaked between February and April, whereas the number of HCoVNL63 infections peaked between April and May. Conclusions. This study describes the features of LRTIs associated with newly identified viruses in children, compared with those associated with known viruses. Additional investigations are required to define the role of HBoV in LRTI. [ABSTRACT FROM AUTHOR]

To understand the molecular basis of observed regional shifts in the genome types of adenovirus type 7 (Ad7) isolated in Korea during nationwide outbreaks from 1995 to 2000, the genetic variabilities of Ad7d and Ad7l were studied by sequence analysis of hexon, fiber, E3. and E4 open reading frame (ORF) 6/7 peptides. One amino acid change in the receptor-binding domain of fiber and 6 amino acid variations in E4 ORF 6/7 were identified between 2 genome types, while no variations were found in hexon and E3. Phylogenetic trees based on hexon, fiber, and E4 suggested that the Ad7 epidemic was probably caused by the introduction of the Japanese Ad7d strains. Our data also provide evidence that the rapid divergence of Ad7d to a novel genome type Ad7l could have been due to viral strategies involving multiple sequence changes in E4. This result suggests fiber and E4 ORF 6/7 peptides participate in the evolution of Ad7. [ABSTRACT FROM AUTHOR]

Investigates possible genetic factors associated with chronic disseminated candidiasis (CDC), a form of Candida species infection observed primarily in patients with acute leukemia. Pilot study of patients with both leukemia and CDC and control patients with leukemia only; Possible contribution of genetic variants of interleukin-4 to the development of CDC in patients with acute leukemia.

Respiratory syncytial virus (RSV) is a major health problem in young children, and host response to severe disease favors a Th2 immune response. To investigate the genetic basis for RSV disease severity, linked variants of 3 Th2 cytokine genes, IL4, IL13, and IL5 (which are clustered on chromosome 5q31.1) were characterized in 105 children who were hospitalized with severe RSV infection and 315 Korean control subjects in a pilot study. A common IL4 haplotype defined at 5 loci, which includes the -589T promoter variant, previously shown to be associated with increased interleukin (IL)-4 transcriptional activity and predisposition to asthma, was overrepresented in patients with severe RSV disease (odds ratio, 1.63; P = .02). These results support the hypothesis that severe RSV disease might be related to increased Th2 response, which is perhaps mediated by overexpression of IL-4, and provide preliminary evidence for a genetic link between severe RSV disease and subsequent wheezing. [ABSTRACT FROM AUTHOR]

Studies the genetic variation and molecular epidemiology of the G protein of respiratory syncytial virus (RSV) using different strains from consecutive epidemics in children's hospital in Seoul, South Korea. Restriction analysis of the entire G protein gene; Replacement of the predominant genotypes with new genotypes during epidemics; Geographic and temporal distinction among strains.

To determine prevalence and genetic structures of new serotype 6D strains of pneumococci, we examined isolates from diverse clinical specimens in South Korea during 1991-2008. Fourteen serotype 6D strains accounted for 10.4% of serogroup 6 pneumococci from blood, sputum, nasopharynx, and throat samples. Serotype 6D strains consisted of 3 sequence types. [ABSTRACT FROM AUTHOR]

A seven-year-old castrated male Yorkshire terrier dog was presented for a recurrent skin disease. Erythematous skin during the first visit progressed from multiple plaques to patch lesions and exudative erosion in the oral mucosa membrane. Biopsy samples were taken from erythematous skin and were diagnosed with epitheliotropic T cell cutaneous lymphoma by histopathology and immunochemical stain. In serum chemistry, the dog had a hypercalcemia (15.7 mg/dl) and mild increased alkaline phosphatase (417 U/l). Immunohistochemistry was performed to detect parathyroid hormone-related peptide (PTH-rP) in epitheliotropic cutaneous lymphoma tissues but the neoplastic cells were not labeled with anti-PTH-rP antibodies. The patient was treated with prednisolone and isotretinoin. However, the dog died unexpectedly. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the clinical features of respiratory syncytial virus (RSV) infection and risk factors for severe RSV disease among Korean children in 2022/2023. A total of 235 children were identified, and 84.3% were hospitalized. Patients under 3 months and 2 years of age accounted for 20.9% and 54.5%, respectively. Pneumonia was diagnosed in 40.9% of children and bronchiolitis in 23.8%. Respiratory support and intensive care were required in 43.4% and 7.7% of patients, respectively. Haemophilus influenzae nasopharyngeal colonization and the presence of underlying disease showed a significant correlation with severity indicators. The clinical impact of RSV infection was high on infants and toddlers, even those having no underlying disease or not being indicated for palivizumab. [ABSTRACT FROM AUTHOR]

This case study explores the use of CD45RA+ depleted lymphocyte infusion as a potential treatment for refractory cytomegalovirus (CMV) disease in an infant with complete DiGeorge syndrome (cDGS). The patient, who had a severe T cell deficiency, initially received ganciclovir but developed resistance. Infusing CD45RA+ depleted CMV-specific lymphocytes from the patient's father resulted in a decrease in CMV viral load. However, the patient ultimately passed away from pneumonia and sepsis. The study suggests that CD45RA+ depleted lymphocyte infusion may be a viable option for treating refractory CMV disease in cDGS patients, but further research is needed. [Extracted from the article]

Background: Enterovirus D68 (EV-D68) is a re-emerging pathogen that is particularly common in children and may cause asthma-like respiratory infection and acute flaccid myelitis. However, in Korea, EV-D68 has never been reported thus far. This study aimed to identify EV-D68 from nasopharyngeal aspirates (NPAs) in Korean children with a respiratory tract infection. Materials and Methods: The EV-D68 reference strain was purchased and blindly used to assess the detection ability of three commercial and one in-house mRT-PCR kit in 2018. Then, we selected children whose specimens were positive for human rhinovirus (HRV) and/or enterovirus (EV) by Allplex mRT-PCR (Seegene, Inc., Seoul, Korea) from April to December 2022. Total RNA was extracted from NPAs, and a partial 5’-UTR gene was amplified and sequenced for the identification of HRV/EV species. Additionally, PCR targeting the VP1 gene was performed to assess EV-D68- positive NPAs, followed by sequencing. Phylogenetic analysis and comparison of amino acid sequence alignments were performed using a partial VP1 gene of our and recent international EV-D68 strains. Results: Among the mRT-PCR kits tested, only the in-house kit was able to detect EV-D68 in 2018. However, we detected three EV-D68 strains among children hospitalized with fever and/or respiratory symptoms in September - December 2022 who tested positive for EV by the Allplex kit. Two of them were healthy toddlers with lower respiratory infections accompanied by new-onset wheezing but no neurologic complications. Among 34 children with lower respiratory infection who tested positive for HRV during the same period, EV-D68 was not detected. Phylogenetic analysis revealed that the first Korean EV-D68 belonged to subclade B3. Amino acid sequence alignment of international subclade B3 EV-D68 strains also showed that our strain is genetically more related to those from Europe than those from Japan. Conclusion: We first detected EV-D68 in three Korean children who had EV detected by the Allplex mRT-PCR kit in 2022. EV-D68 also circulated in Korea in fall 2022, but the prevalence and severity seemed to be lower than those in previous reports from other countries. [ABSTRACT FROM AUTHOR]

Objectives This ambidirectional intervention study was performed to examine the impact of a change in antibiotic policy on extended-spectrum β-lactamase (ESBL) prevalence in a childrens hospital with a high prevalence of ESBL production among Escherichia coli and Klebsiella pneumoniae. Methods The use of extended-spectrum cephalosporins was restricted and use of β-lactam/ β-lactamase inhibitor combinations was encouraged from 2002. All strains of E. coli and K. pneumoniae isolated from sterile body fluids from 1999 to 2005 were analysed for β-lactamase production and the prevalences of ESBL production were compared at three periods; pre-intervention (1999–2001), transitional period (2002–03) and post-intervention (2004–05). Results Comparing the pre- and post-intervention periods, overall piperacillin/tazobactam use increased from 2.2 to 108.0 days on antibiotics/1000 patient admission days/year (AD) (P for trend P for trend E. coli (n = 128) and K. pneumoniae (n = 124), the overall prevalence of ESBL producers decreased from 39.8% (41/103) to 22.8% (18/79) (P for trend = 0.018). This decreasing trend of ESBL production was more evident for K. pneumoniae (64.1% to 25.6%; P for trend E. coli (25.0% to 19.4%; P for trend = 0.514). The mortality rates of invasive disease caused by E. coli or K. pneumoniae remained unchanged. Conclusions The substitution of piperacillin/tazobactam for extended-spectrum cephalosporins successfully decreased the prevalence of ESBL production of K. pneumoniae and E. coli in an institute for children where ESBLs were endemic. The impact of change in antibiotic policy was more evident in K. pneumoniae than E. coli. [ABSTRACT FROM AUTHOR]

In April 2020, the Ministry of Food and Drug Safety licensed a hexavalent combined diphtheria and tetanus toxoids and acellular pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib) conjugated to tetanus protein, and hepatitis B (HepB) (recombinant DNA) vaccine, DTaPIPVHibHepB (Hexaxim, Sanofi Pasteur), for use as a 3dose primary series in infants aged 2, 4, and 6 months. The DTaPIPVHibHepB vaccine is highly immunogenic and safe and provides a longterm immune response based on studies performed in a variety of settings in many countries, including Korea. This report summarizes the Committee on Infectious Diseases of the Korean Pediatric Society guidelines for the use of this newly introduced hexavalent combination vaccine. [ABSTRACT FROM AUTHOR]

During the 2019 domestic measles outbreak in Korea, measles occurred in healthcare workers with two doses of the measles, mumps and rubella vaccine, and the strict application of the Occupational Safety and Health Act required medical institutions to identify healthcare workers' immunity to measles and vaccinate the susceptible pockets. In response to the frontline medical institutions' request to review the measles recommendations and guidelines, the Korean Society of Infectious Diseases held a roundtable discussion on the causes of measles outbreak, timing of vaccinations, antibody tests, and booster vaccinations for healthcare workers, and financial support from the government and municipality as well as response strategies against the outbreak in healthcare settings. In Korea, the seroprevalence of measles is decreasing in the vaccine-induced immunity group during the maintenance of measles elimination over several years. The susceptible group against measles is in their 20s and 30s, and this may be because of waning immunity rather than nonresponse considering Korea's vaccine policy. The risk of measles nosocomial infection from community increases as these susceptible pockets actively engage in medical institutions. Thus, data on the immunity of low seroprevalence group in Korea are needed, further discussion is needed on the booster vaccination based on the data. Especially, antibody testing and vaccination in healthcare workers may be necessary to prevent the spread of measles in medical insutitutions, and further discussion is needed regarding specific testing methods, and the timing and frequency of test and vaccination. [ABSTRACT FROM AUTHOR]

Along with positive SARS-CoV-2 RNA in nasopharyngeal swabs, viral RNA was detectable at high concentration for >3 weeks in fecal samples from 12 mildly symptomatic and asymptomatic children with COVID-19 in Seoul, South Korea. Saliva also tested positive during the early phase of infection. If proven infectious, feces and saliva could serve as transmission sources. [ABSTRACT FROM AUTHOR]