Contact Investigations With a Single Tuberculin Skin Test on Infants Exposed to Tuberculosis in a Postpartum Care Center During the Neonatal Period.

BACKGROUND: Tuberculosis (TB) exposure in congregate settings related to neonates is a serious medical and social issue. TB exposure happens during the neonatal period, but contact investigations for exposed infants are usually conducted after the neonatal period. Generally, recommendations for screening and managing close contact are different for neonates and children. Thus, there are challenges in contact investigations. We aimed to report contact investigations with a single tuberculin skin test (TST) on infants exposed to infectious TB in a postpartum care center. METHODS: The index case was a healthcare worker with active pulmonary TB: sputum acid-fast bacilli smear negative, culture positive, and no cavitary lesion. All exposed infants underwent medical examinations and chest X-ray. After TB disease was ruled out, contacts received window period prophylaxis with isoniazid (INH) until three months after the last exposure. TST was performed only once after completing the prophylaxis. RESULTS: A total of 288 infants were selected as high-priority contacts. At the initial contact investigation, the age of infants ranged from 8 to 114 days. None of these exposed infants had TB disease. The prevalence of latent TB infection (LTBI) was 25.3% (73/288; 95% confidence interval [CI], 20.7-30.7). There were no serious adverse events related to the window period prophylaxis or LTBI treatment with INH. During the 1-year follow-up period, no infants progressed to overt TB disease. The size of TST induration in infants vaccinated with percutaneous Bacillus Calmette-Guérin (BCG) vaccine was significantly larger than that of infants vaccinated with intradermal BCG vaccine (median, 8 mm vs. 5 mm; P = 0.002). In multiple logistic regression analysis, independent factors associated with TST positivity (≥ 10 mm induration) were male (adjusted odds ratio [aOR], 2.98; 95% CI, 1.6-5.64), percutaneous BCG vaccination (aOR, 3.30; 95% CI, 1.75-6.48), TST reading between 60 and 72 hours after injecting purified protein derivative (aOR, 2.87; 95% CI, 1.53-5.49), and INH prophylaxis more than four weeks (aOR, 0.49; 95% CI, 0.25-0.94). CONCLUSION: A single TST at three months after the last TB exposure with INH prophylaxis could be used as a main protocol in contact investigations for infants exposed to infectious TB during the neonatal period in congregate settings in Korea.

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.

Twenty-Five Year Trend Change in the Etiology of Pediatric Invasive Bacterial Infections in Korea, 1996-2020.

BACKGROUND: The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). METHODS: A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. RESULTS: A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = -0.430, P = 0.036), H. influenzae (rs = -0.922, P < 0.001), while trend toward an increase in the relative proportion of S. aureus (rs = 0.850, P < 0.001), S. agalactiae (rs = 0.615, P = 0.001), and S. pyogenes (rs = 0.554, P = 0.005). CONCLUSION: In the proportion of IBIs over a 24-year period between 1996 and 2019, we observed a decreasing trend for S. pneumoniae and H. influenzae and an increasing trend for S. aureus, S. agalactiae, and S. pyogenes in children > 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.

A Case Report of Postinfectious Bronchiolitis Obliterans After Coronavirus Disease 2019 in a 10-Year-Old Child.

Coronavirus disease 2019 (COVID-19) is usually less severe in children and adolescents than in adults. However, it can cause severe respiratory illness in a small proportion of children with risk factors. Here, we report a rare case of a 10-year-old boy with postinfectious bronchiolitis obliterans that developed after pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This patient was previously healthy apart from a high body mass index (BMI, 30.13; 99.6th percentile for the age bracket), history of preterm birth (35 weeks), and low birth weight (1,850 g). He had persistent exertional dyspnea after recovering from SARS-CoV-2-related pneumonia. Spirometry revealed obstructive lung disease with the following results: predicted forced vital capacity (FVC%pred), 71%; forced expiratory volume in 1 second (FEV1%pred), 63%; FEV1/FVC, 0.81; and forced expiratory flow25-75%pred, 55%. Chest computed tomography showed multifocal areas of parenchymal hyperlucency and mosaic attenuation in both lungs. This case suggests that careful observation of children with obesity and low birth weight is necessary after recovery from SARS-CoV-2-related pneumonia.

Efficacy of tetracyclines and fluoroquinolones for the treatment of macrolide-refractory Mycoplasma pneumoniae pneumonia in children: a systematic review and meta-analysis.

BACKGROUND: Mycoplasma pneumoniae is a common pathogen that causes community-acquired pneumonia in school-age children. Macrolides are considered a first-line treatment for M. pneumoniae infection in children, but macrolide-refractory M. pneumoniae (MRMP) strains have become more common. In this study, we assessed the efficacy of tetracyclines and fluoroquinolones in MRMP treatment in children through a systematic review and meta-analysis. METHODS: Two reviewers individually searched 10 electronic databases (Medline/Pubmed, Embase, the Cochrane Library, and core Korean, Chinese, and Japanese journals) for papers published from January 1, 1990 to March 8, 2018. The following data for each treatment group were extracted from the selected studies: intervention (tetracyclines and fluoroquinolones/comparator), patient characteristics (age and sex), and outcomes (fever duration, hospital stay length, treatment success rate, and defervescence rates 24, 48, and 72 h after starting treatment). RESULTS: Eight studies involving 537 participants were included. Fever duration and hospital stay length were shorter in the tetracycline group than in the macrolide group (weighted mean difference [WMD] = - 1.45, 95% confidence interval [CI]: - 2.55 to - 0.36, P = 0.009; and WMD = - 3.33, 95% CI: - 4.32 to - 2.35, P < 0.00001, respectively). The therapeutic efficacy was significantly higher in the tetracycline group than in the macrolide group (odds ratio [OR]: 8.80, 95% CI: 3.12-24.82). With regard to defervescence rate, patients in the tetracycline group showed significant improvement compared to those in the macrolide group (defervescence rate after 24 h, OR: 5.34, 95% CI: 1.81-15.75; after 48 h, OR 18.37, 95% CI: 8.87-38.03; and after 72 h, OR: 40.77, 95% CI: 6.15-270.12). There were no differences in fever improvement within 24 h in patients in the fluoroquinolone group compared to those in the macrolide group (OR: 1.11, 95% CI: 0.25-5.00), although the defervescence rate was higher after 48 h in the fluoroquinolone group (OR: 2.78, 95% CI: 1.41-5.51). CONCLUSION: Tetracyclines may shorten fever duration and hospital stay length in patients with MRMP infection. Fluoroquinolones may achieve defervescence within 48 h in patients with MRMP infection. However, these results should be carefully interpreted as only a small number of studies were included, and they were heterogeneous.

Ampicillin-sulbactam monotherapy in infants with febrile urinary tract infections.

BACKGROUND: Cephalosporin is the most commonly used empirical agent for urinary tract infections (UTIs) in children. However, increasing use of cephalosporins can lead to an increase in resistant pathogens. This study therefore aims to investigate the effects of monotherapy with ampicillin-sulbactam as an alternative to cephalosporins. METHODS: All 2- to 24-month-old patients who were hospitalized at Pusan National University Children's Hospital due to a first episode of a febrile UTI during the 2-year period from 2012 to 2014 were included in the study. The subjects were divided into two groups according to their empirical therapy (cefotaxime or ampicillin-sulbactam). We determined the patients' UTI pathogens and their antibiotic susceptibilities and compared the effectiveness and the occurrence of adverse effects of ampicillin-sulbactam and cephalosporin therapy. RESULTS: Forty-six patients were treated with cefotaxime (group A) and 41 patients with ampicillin-sulbactam as the empirical antibiotic (group B). The most common pathogen in both groups was Escherichia coli, and antibiotic susceptibilities of the bacterial strains isolated from both groups were similar in ampicillin-sulbactam and cefotaxime. In addition, there was no significant difference in the duration of fever after treatment between the two groups (group A: 2.0 versus group B: 3.0, P = 0.331). There were no treatment failures and no recurrence in either group, even in patients with resistant pathogens. The most common side effect of the antibiotic agents was diarrhea. CONCLUSIONS: Ampicillin-sulbactam could be an effective alternative to cephalosporin as empiric antibiotic for the treatment of first-episode UTI in patients under 24 months of age.

Pediatric and Parents' Attitudes Towards COVID-19 Vaccines and Intention to Vaccinate for Children.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccination is necessary to reach herd immunity and essential for mitigating the spread of the pandemic. In May 2021, the US FDA and the EU have expanded the emergency use authorization for a COVID-19 vaccine to children aged 12 to 15. The aim of this study was to investigate parental acceptability of COVID-19 vaccination for their children, factors affecting their acceptability, and children's perceptions of COVID-19 vaccines in Republic of Korea. METHODS: We conducted a questionnaire survey at two tertiary hospitals from May 25, 2021 to June 3, 2021. Subjects were parents having children under 18 years and children aged 10-18 years. RESULTS: Two hundred twenty-six parents and 117 children aged 10-18 years were included in the final analysis. Overall, 76.5% and 64.2% of parents intended to get vaccinated against COVID-19 and intended to have their children vaccinated, respectively. However, only 49.6% of children responded that they would get COVID-19 vaccination. In the multivariate analysis, high confidence in the safety of COVID-19 vaccines (adjusted odds ratio [AOR], 4.87; 95% confidence interval [CI], 1.32-24.12), parents' willingness to vaccinate themselves (AOR, 19.42; 95% CI, 6.85-64.00), and awareness of the need to vaccinate children against COVID-19 (AOR, 13.15; 95% CI, 4.77-41.27) were associated with positive factors intention to vaccinate their children. CONCLUSION: This study provides insight into how parents think about the COVID-19 vaccine for their children in South Korea. Our findings could be referenced in establishing a policy for childhood COVID-19 vaccination in the future.

Controlling an Outbreak of Multidrug-resistant Acinetobacter baumannii in a Pediatric Intensive Care Unit: a Retrospective Analysis.

BACKGROUND: Multidrug-resistant Acinetobacter baumannii (MDRAB) is widespread among intensive care units worldwide, posing a threat to patients and the health system. We describe the successful management of a MDRAB outbreak by implementing an infection-control strategy in a pediatric intensive care unit (PICU). METHODS: This retrospective study investigated the patients admitted to the PICU in periods 1 (8 months) and 2 (7 months), from the index MDRAB case to intervention implementation, and from intervention implementation to cessation of MDRAB spread. An infection-control strategy was designed following six concepts: 1) cohort isolation of colonized patients, 2) enforcement of hand hygiene, 3) universal contact precautions, 4) environmental management, 5) periodic surveillance culture study, and 6) monitoring and feedback. RESULTS: Of the 427 patients, 29 were confirmed to have MDRAB colonization, of which 18 had MDRAB infections. Overall incidence per 1,000 patient days decreased from 7.8 (period 1) to 5.8 (period 2). The MDRAB outbreak was declared terminated after the 6-month follow-up following period 2. MDRAB was detected on the computer keyboard and in condensed water inside the ventilator circuits. The rate of hand hygiene performance was the lowest in the three months before and after index case admission and increased from 84% (period 1) to 95% (period 2). Patients with higher severity, indicated by a higher Pediatric Risk of Mortality III score, were more likely to develop colonization (P = 0.030), because they had invasive devices and required more contact with healthcare workers. MDRAB colonization contributed to an increase in the duration of mechanical ventilation and PICU stay (P < 0.001), but did not affect mortality (P = 0.273). CONCLUSION: The MDRAB outbreak was successfully terminated by the implementation of a comprehensive infection-control strategy focused on the promotion of hand hygiene, universal contact precautions, and environmental management through multidisciplinary teamwork.

The First Case of an Infant with Familial A20 Haploinsufficiency in Korea.

Haploinsufficiency of A20 (HA20) is a newly described autoinflammatory disease caused by loss-of-function mutations in the TNFAIP3 gene. Clinical phenotypes are heterogenous and resemble Behçet's disease, juvenile idiopathic arthritis, inflammatory bowel disease, or periodic fever syndrome, with symptoms developing at an early age. Here, we report the first case of infantile familial HA20 in Korea, which mimics neonatal lupus erythematosus (NLE). A 2-month-old infant exhibited symptoms including recurrent fever, erythematous rashes, and oral ulcers, with elevated liver enzymes, and tested positive for several autoantibodies, similar to systemic lupus erythematosus (SLE); therefore, she was suspected to have NLE. However, six months after birth, symptoms and autoantibodies persisted. Then, we considered the possibility of other diseases that could cause early onset rashes and abnormal autoantibodies, including autoinflammatory syndrome, monogenic SLE, or complement deficiency, all of which are rare. The detailed family history revealed that her father had recurrent symptoms, including oral and genital ulcers, knee arthralgia, abdominal pain, and diarrhea. These Behcet-like symptoms last for many years since he was a teenager, and he takes medications irregularly only when those are severe, but doesn't want the full-scale treatment. Whole-exome sequencing was conducted to identify a possible genetic disorder, which manifested as pathogenic variant nonsense mutation in the TNFAIP3 gene, leading to HA20. In conclusion, HA20 should be considered in the differential diagnosis of an infant with an early-onset dominantly inherited inflammatory disease that presents with recurrent oral and genital ulcerations and fluctuating autoantibodies. Additionally, it also should be considered in an infant with suspected NLE, whose symptoms and abnormal autoantibodies persist.

Pediatric intensive care unit admission due to respiratory syncytial virus: Retrospective multicenter study.

BACKGROUND: We investigated the characteristics and clinical outcomes of respiratory syncytial virus (RSV)-related pediatric intensive care unit (PICU) hospitalization and assessed the palivizumab (PZ) prophylaxis eligibility according to different guidelines from Korea, EU, and USA. METHODS: In this multicenter study, children <18 years of age hospitalized in six PICU from different hospitals due to severe RSV infection between September 2008 and March 2013 were included. A retrospective chart review was performed. RESULTS: A total of 92 patients were identified. The median length of PICU stay was 6 days (range, 1-154 days) and median PICU care cost was USD2,741 (range, USD556-98 243). Of 62 patients who were <2 years old at the beginning of the RSV season, 33 (53.2%) were high-risk patients for severe RSV infection. Hemodynamically significant congenital heart disease (22.6%) was the most common risk factor, followed by chronic lung disease (11.3%), neuromuscular disease or congenital abnormality of the airway (NMD/CAA) (11.3%), and prematurity (8.1%). The percentage of patients eligible for PZ prophylaxis ranged from 38.7% to 48.4% based on the guidelines, but only two (2.2%) received PZ ≤30 days prior to PICU admission. The median duration of mechanical ventilation was longer in children with NDM/CAA than in those without risk factors (26 days; range, 24-139 days vs 6 days, range, 2-68 days, P = 0.033). RSV-attributable mortality was 5.4%. CONCLUSIONS: Children <2 years old with already well-known high risks represent a significant proportion of RSV-related PICU admissions. Increasing of the compliance for PZ prophylaxis practice among physicians is needed. Further studies are needed to investigate the burden of RSV infection in patients hospitalized in PICU, including children with NMD/CAA.

Erratum: Addition of a Co-Author: Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (2006-2010): a Retrospective Multicenter Study.

This corrects the article on e45 in vol. 33, PMID: 29349940.

Genetic structures of invasive Streptococcus pneumoniae isolates from Korean children obtained between 1995 and 2013.

BACKGROUND: Understanding the population genetics of pneumococci will allow detection of changes in the prevalence of circulating genotypes and evidence for capsular switching. We aimed to analyze the genetic structure of invasive pneumococcal isolates obtained from children before and after the use of pneumococcal conjugate vaccines (PCVs) in Korea. METHODS: A total of 285 invasive pneumococcal isolates were analyzed using serotyping, multilocus sequence typing, and antimicrobial susceptibility testing. We classified the isolation year to pre-PCV7 (1995-2003; n = 70), post-PCV7 (2004-2010; n = 142), and post-PCV13 (2011-2013; n = 73) periods. RESULTS: Of the 10 clonal complexes (CCs), antibiotic-resistant international clones, CC320 (31.6%), CC81 (14.7%), and CC166 (6.7%) were the main complexes. Serotype 19A was the main serotype of CC320 throughout the periods. Serotypes of CC81 mainly comprised of 23F (53.3%) in pre-PCV7 period and replaced by non-vaccine types (NVTs; 6C [10%], 13 [30%], 15A [40%], and 15B/C [20%]) in post-PCV13 period. The main serotype responsible for CC166 also changed from 9 V (80%) in pre-PCV7 to NVT 11A (50%) in post-PCV13 periods. Non-susceptibility to penicillin (42.3%) was the highest in CC320, increasing from 0 to 76%. CONCLUSION: The genetic structures of invasive pneumococcal isolates in Korean children have changed concomitantly with serotype after the implementation of PCVs.

Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (2006-2010): a Retrospective Multicenter Study.

BACKGROUND: Invasive bacterial infections in apparently immunocompetent children were retrospectively analyzed to figure causative bacterial organisms in Korea. METHODS: A total of 947 cases from 25 university hospitals were identified from 2006 to 2010 as a continuance of a previous 10-year period study from 1996 to 2005. RESULTS: Escherichia coli (41.3%), Streptococcus agalactiae (27.7%), and Staphylococcus aureus (27.1%) were the most common pathogens in infants < 3 months of age. S. agalactiae was the most prevalent cause of meningitis and pneumonia and E. coli was the major cause of bacteremia without localizing signs in this group. In children 3 to 59 months of age, Streptococcus pneumoniae (54.2%), S. aureus (20.5%), and Salmonella spp. (14.4%) were the most common pathogens. S. pneumoniae was the leading cause of pneumonia (86.0%), meningitis (65.0%), and bacteremia without localizing signs (49.0%) in this group. In children ≥ 5 years of age, S. aureus (62.8%) was the predominant pathogen, followed by Salmonella species (12.4%) and S. pneumoniae (11.5%). Salmonella species (43.0%) was the most common cause of bacteremia without localizing signs in this group. The relative proportion of S. aureus increased significantly over the 15-year period (1996-2010) in children ≥ 3 months of age (P < 0.001), while that of Haemophilus influenzae decreased significantly in both < 3 months of age group (P = 0.036) and ≥ 3 months of age groups (P < 0.001). CONCLUSION: S. agalactiae, E. coli, S. pneumoniae, and S. aureus are common etiologic agents of invasive bacterial infections in Korean children.

Can absence of pyuria exclude urinary tract infection in febrile infants? About 2011 AAP guidelines on UTI.

BACKGROUND: The aim of this study was to describe clinical and laboratory characteristics of urinary tract infection (UTI) without significant pyuria in young children aged 2-24 months. METHODS: The subjects consisted of infants and young children with febrile UTI treated at Pusan National University Children's Hospital, Korea. Group A included 283 patients with definite UTI who fulfilled the revised American Academy of Pediatrics diagnostic criteria, and group B included 19 patients with presumed UTI who had significant culture of uropathogens without pyuria, bacteriuria or other focus of infection. RESULTS: Duration of fever before hospital visit in group B was significantly shorter than in group A (17.7 ± 14.0 vs 34.5 ± 30.7 h). Most patients in group B (17/19, 89.5%) came to the hospital within 24 h of onset of fever. Acute scintigraphic lesions were found in 47.8% of patients in group A and 50% in group B. Underlying urological abnormalities such as vesicoureteral reflux and obstructive uropathy were found in 24.5% of patients in group A and in 33.3% of patients in group B (P = 0.74). CONCLUSIONS: Clinicians cannot exclude UTI on the absence of pyuria in young children aged 2-24 months.

Early Changes in the Serotype Distribution of Invasive Pneumococcal Isolates from Children after the Introduction of Extended-valent Pneumococcal Conjugate Vaccines in Korea, 2011-2013.

This study was performed to measure early changes in the serotype distribution of pneumococci isolated from children with invasive disease during the 3-year period following the introduction of 10- and 13-valent pneumococcal conjugate vaccines (PCVs) in Korea. From January 2011 to December 2013 at 25 hospitals located throughout Korea, pneumococci were isolated among children who had invasive pneumococcal disease (IPD). Serotypes were determined using the Quellung reaction, and the change in serotype distribution was analyzed. Seventy-five cases of IPD were included. Eighty percent of patients were aged 3-59 months, and 32% had a comorbidity that increased the risk of pneumococcal infection. The most common serotypes were 19A (32.0%), 10A (8.0%), and 15C (6.7%). The PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, 23F, and 6A) accounted for 14.7% of the total isolates and the PCV13 minus PCV7 types (1, 3, 5, 7F and 19A) accounted for 32.0% of the total isolates. Serotype 19A was the only serotype in the PCV13 minus PCV7 group. The proportion of serotype 19A showed decreasing tendency from 37.5% in 2011 to 22.2% in 2013 (P = 0.309), while the proportion of non-PCV13 types showed increasing tendency from 45.8% in 2011 to 72.2% in 2013 (P = 0.108). Shortly after the introduction of extended-valent PCVs in Korea, serotype 19A continued to be the most common serotype causing IPD in children. Subsequently, the proportion of 19A decreased, and non-vaccine serotypes emerged as an important cause of IPD. The impact of extended-valent vaccines must be continuously monitored.

Parasternal mass revealing as a postvaccinal Bacillus Calmette-Guérin (BCG)-elicited sternal osteomyelitis.

Although osteomyelitis is a very rare complication of Bacillus Calmette-Guérin (BCG) vaccination, sternal osteomyelitis as a late complication of BCG vaccination diagnosed by polymerase chain reaction (PCR) in a child is described.We might consider BCG osteomyelitis in the case of osteomyelitis without bacterial isolation within a year after BCG vaccination, the absence of pulmonary foci, and a contact to the patient with tuberculosis.

Abdominal tuberculosis with periportal lymph node involvement mimicking pancreatic malignancy in an immunocompetent adolescent.

Abdominal tuberculosis manifesting as isolated lymphadenopathy is rare, particularly in children. Tuberculous involvement of the pancreatic head and peripancreatic area can simulate a neoplasm of the pancreatic head. To our knowledge, obstructive jaundice caused by tuberculous lymphadenopathy has not been reported in children or adolescents. Here we present radiologic findings in a case of tuberculous lymphadenopathy that mimicked malignancy of the pancreatic head and caused obstructive jaundice in an immunocompetent adolescent.

Enterococcal bacteremia in children: Clinical Significance of vancomycin resistance.

BACKGROUND: We aimed to describe the clinical and microbiological characteristics of enterococcal bacteremia, as well as the effect of Enterococcus resistance against vancomycin on clinical outcomes in Korean children. METHODS: We retrospectively reviewed the medical records of children diagnosed with enterococci isolated from blood cultures at Pusan National University Children's Hospital between December 2009 and November 2021. RESULTS: In total, 64 patients were enrolled in the study. The median age was 0 years (range 0-15), and 43 (67.2%) patients were male. Enterococcus faecalis (50%) was the most commonly identified bacterial strain. Significant underlying diseases were present in 60 patients (93.8%), and the source of bacteremia was identified in 36 patients (56.3%). Among these, intravascular device was the most common identifiable source. Fifty-six (87.5%) patients had previously received broad-spectrum antibiotics and 54 (84.4%) patients were nosocomial in origin. Twenty-nine (45.3%) strains were resistant to ampicillin, and 16 (25%) strains were resistant to vancomycin. All patients with vancomycin-resistant enterococci (VRE) had underlying disease (P = 0.199), and focus of bacteremia was significantly more frequent in VRE patients (P = 0.014). Of all the patients, after appropriate antibiotic treatment, five (7.8%) patients had recurrent enterococcal bacteremia, and seven (10.9%) patients were diagnosed with bacteremia, defined as other pathogens from blood culture. The 30-day mortality rate was 7.8%. CONCLUSION: Enterococcal bacteremia in children is usually nosocomial and occurs in children with serious underlying diseases. Because the number of enrolled patients and mortality were small in our study, it is difficult to identify whether the factor that determines prognosis in patients with enterococcal bacteremia is VRE or an underlying disease. Further studies with a large number of patients in a specific group are needed.

Tonic NMDAR Currents of NR2A-Containing NMDARs Represent Altered Ambient Glutamate Concentration in the Supraoptic Nucleus.

NMDA receptors (NMDARs) modulate glutamatergic excitatory tone in the brain via two complementary modalities: a phasic excitatory postsynaptic current and a tonic extrasynaptic modality. Here, we demonstrated that the tonic NMDAR-current (I NMDA) mediated by NR2A-containing NMDARs is an efficient biosensor detecting the altered ambient glutamate level in the supraoptic nucleus (SON). I NMDA of magnocellular neurosecretory cells (MNCs) measured by nonselective NMDARs antagonist, AP5, at holding potential (V holding) -70 mV in low concentration of ECF Mg2+ ([Mg2+]o) was transiently but significantly increased 1-week post induction of a DOCA salt hypertensive model rat which was compatible with that induced by a NR2A-selective antagonist, PEAQX (I PEAQX) in both DOCA-H2O and DOCA-salt groups. In agreement, NR2B antagonist, ifenprodil, or NR2C/D antagonist, PPDA, did not affect the holding current (I holding) at V holding -70 mV. Increased ambient glutamate by exogenous glutamate (10 mM) or excitatory amino acid transporters (EAATs) antagonist (TBOA, 50 mM) abolished the I PEAQX difference between two groups, suggesting that attenuated EAATs activity increased ambient glutamate concentration, leading to the larger I PEAQX in DOCA-salt rats. In contrast, only ifenprodil but not PEAQX and PPDA uncovered I NMDA at V holding +40 mV under 1.2 mM [Mg2+]o condition. I ifenprodil was not different in DOCA-H2O and DOCA-salt groups. Finally, NR2A, NR2B, and NR2D protein expression were not different in the SON of the two groups. Taken together, NR2A-containing NMDARs efficiently detected the increased ambient glutamate concentration in the SON of DOCA-salt hypertensive rats due to attenuated EAATs activity.

A phase 3, single-arm, open-label study to evaluate the safety, tolerability, and immunogenicity of a 15-valent pneumococcal conjugate vaccine, V114, in a 3+1 regimen in healthy infants in South Korea (PNEU-PED-KOR).

There is an ongoing burden of pneumococcal disease in children despite the use of pneumococcal conjugate vaccines (PCVs). This phase 3, open-label, single-arm, multisite, descriptive study was designed to evaluate the safety and immunogenicity of a 3 + 1 regimen of V114 (VAXNEUVANCE™), a 15-valent PCV, in South Korean infants and toddlers. Adverse events (AEs) were reported for 14 d following any vaccination, and throughout the study period for serious AEs. Serotype-specific immunoglobulin G (IgG) response rates (proportion of participants meeting an IgG threshold value of ≥0.35 µg/mL) and geometric mean concentrations (GMCs) for the 15 serotypes at 30 d postdose 3 (PD3) and at 30 d postdose 4 (PD4) were evaluated as endpoints. Healthy infants enrolled at 42-90 d after birth were vaccinated with V114 (N = 57). The most commonly reported AEs were those solicited in the trial. The majority of reported AEs were transient and of mild or moderate intensity. Few serious AEs were reported; none were vaccine related. No participants died nor discontinued the study vaccine because of an AE. V114 was immunogenic for all 15 serotypes contained in the vaccine, as assessed by IgG response rates at 30 d PD3 and IgG GMCs at 30 d PD3 and at 30 d PD4. V114 was well tolerated and immunogenic when administered as a 3 + 1 regimen in healthy South Korean infants and toddlers.

Despite the use of pneumococcal vaccines, the burden of pneumococcal disease in children persists. V114, a 15-valent pneumococcal conjugate vaccine, was immunogenic and well-tolerated in healthy South Korean infants and toddlers.