Evolutionary dynamics of the novel ST22-PT methicillin-resistant Staphylococcus aureus clone co-harbouring Panton-Valentine leucocidin and duplicated toxic shock syndrome toxin 1 genes.

OBJECTIVES: Globally, the isolation of community-associated methicillin-resistant Staphylococcus aureus (MRSA) harbouring both the Panton-Valentine leucocidin (PVL) and toxic shock syndrome toxin 1 (TSST-1) genes is rare. However, we encountered an outbreak of the ST22-PT clone exhibiting this phenotype in Japan. Notably, the TSST-1 gene was duplicated in most of the strains. This study aimed to elucidate the mechanisms underlying this gene duplication. METHODS: A total of 90 MRSA isolates were collected from the skin of outpatients in Fukuoka City, Japan, between 2017 and 2019. Whole-genome sequencing was performed on MRSA strains that were PVL and TSST-1 positive. RESULTS: A total of 43 (47.8%) strains produced TSST-1, 20 (22.2%) produced PVL, and 16 (17.8%) produced both. Fifteen isolates were classified as ST22/SCCmec type IVa (ST22-PT clone) and one as ST1/SCCmec type V (ST1-PT clone). Three distinct ST22-PT clones were identified: Fukuoka clone I (one PVL gene and one TSST-1 gene), Fukuoka clone II (addition of a TSST-1 gene to Fukuoka clone I), and Fukuoka clone III (marked by a chromosomal inversion in a large region from Fukuoka clone II). DISCUSSION: Fukuoka clone I may have integrated a novel pathogenicity island bearing the TSST-1 gene, leading to the emergence of Fukuoka clone II with a duplicated TSST-1 gene. This duplication subsequently instigated a chromosomal inversion in a large region owing to the homologous sequence surrounding TSST-1, giving rise to Fukuoka clone III. These findings provide crucial insights into the genetic evolution of MRSA.

Clinical Characteristics of Cryopyrin-Associated Periodic Syndrome and Long-Term Real-World Efficacy and Tolerability of Canakinumab in Japan: Results of a Nationwide Survey.

OBJECTIVE: We assess the clinical characteristics of patients with cryopyrin-associated periodic syndrome (CAPS) in Japan and evaluate the real-world efficacy and safety of interleukin-1 (IL-1) inhibitors, primarily canakinumab. METHODS: Clinical information was collected retrospectively, and serum concentrations of canakinumab and cytokines were analyzed. RESULTS: A total of 101 patients were included, with 86 and 15 carrying heterozygous germline and somatic mosaic mutations, respectively. We identified 39 mutation types, and the common CAPS-associated symptoms corresponded with those in previous reports. Six patients (5.9% of all patients) died, with four of the deaths caused by CAPS-associated symptoms. Notably, 73.7% of patients (100%, 79.6%, and 44.4% of familial cold autoinflammatory syndrome, Muckle-Wells syndrome, and chronic infantile neurological cutaneous articular syndrome/neonatal onset multisystem inflammatory disease, respectively) achieved complete remission with canakinumab, and early therapeutic intervention was associated with better auditory outcomes. In some patients, canakinumab treatment stabilized the progression of epiphysial overgrowth and improved height gain, visual acuity, and renal function. However, 23.7% of patients did not achieve inflammatory remission with crucial deterioration of organ damage, with two dying while receiving high-dose canakinumab treatment. Serological analysis of canakinumab and cytokine concentrations revealed that the poor response was not related to canakinumab shortage. Four inflammatory nonremitters developed inflammatory bowel disease (IBD)-unclassified during canakinumab treatment. Dual biologic therapy with canakinumab and anti-tumor necrosis factor-α agents was effective for IBD- and CAPS-associated symptoms not resolved by canakinumab monotherapy. CONCLUSION: This study provides one of the largest epidemiologic data sets for CAPS. Although early initiation of anti-IL-1 treatment with canakinumab is beneficial for improving disease prognosis, some patients do not achieve remission despite a high serum concentration of canakinumab. Moreover, IBD may develop in CAPS after canakinumab treatment.

CD14 down-modulation as a real-time biomarker in Kawasaki disease.

Objectives: The objectives of this study were to investigate the pathophysiology of Kawasaki disease (KD) from immunological and oxidative stress perspectives, and to identify real-time biomarkers linked to innate immunity and oxidative stress in KD. Methods: We prospectively enrolled 85 patients with KD and 135 patients with diverse conditions including immune, infectious and non-infectious diseases for this investigation. Flow cytometry was used to analyse the surface expression of CD14, CD38 and CD62L on monocytes, along with a quantitative assessment of CD14 down-modulation. Additionally, oxidative stress levels were evaluated using derivatives of reactive oxygen metabolites (d-ROMs) and antioxidant capacity measured by a free radical elective evaluator system. Results: During the acute phase of KD, we observed a prominent CD14 down-modulation on monocytes, reflecting the indirect detection of circulating innate immune molecular patterns. Moreover, patients with KD showed a significantly higher CD14 down-modulation compared with infectious and non-infectious disease controls. Notably, the surface expression of CD14 on monocytes was restored concurrently with responses to intravenous immunoglobulin and infliximab treatment in KD. Furthermore, d-ROM levels in patients with KD were significantly elevated compared with patients with infectious and non-infectious diseases. Following intravenous immunoglobulin treatment, oxidative stress levels decreased in patients with KD. Conclusion: Monitoring CD14 down-modulation on monocytes in real-time is a valuable strategy for assessing treatment response, distinguishing KD relapse from concomitant infections and selecting second-line therapy after IVIG treatment in KD patients. The interplay between inflammation and oxidative stress likely plays a crucial role in the development of KD.

Catheter-associated urinary tract infection and urinary tract abnormalities in young children: A retrospective study.

INTRODUCTION: Studies investigating the role of urinary tract abnormalities in the development of catheter-associated urinary tract infections (CAUTI) in young children are limited. Thus, in the present study, we aimed to determine whether there is an association between CAUTI and urinary tract abnormalities. METHODS: We performed abdominal imaging studies on all patients aged <6 years with CAUTI admitted to the pediatric intensive care units (PICU) and high care unit (HCU) at Keio university or Fukuoka Children's Hospital from April 1, 2018 to July 31, 2022. Among 40 children who developed CAUTI, 13 (33 %) had abnormal urogenital images. Further, two case-control studies were conducted before and after propensity score matching, and the groups were compared using multivariable logistic regression models to analyze the effects of various factors on CAUTI development. RESULTS: In the multivariate logistic regression models, abnormal urogenital images (OR 5.30 [95 % CI, 2.40-11.7] and OR 3.44 [95 % CI, 1.16-9.93]) and duration of catheterization >10 days (OR 2.76 [95 % CI, 1.28-5.96] and OR 3.44 [95 % CI, 1.16-9.93]) were found to be significantly associated with development of CAUTI, both before (39 cases, 459 controls) and after propensity score matching (36 cases, 72 controls). Further, CAUTI in young children in the PICU or HCU was significantly associated with imaging abnormalities of the urinary tract. CONCLUSIONS: These results suggest that not only the presence of catheters, but also urinary tract malformations may contribute to the development of CAUTI in young children.

Clinical Usefulness of T-Cell Receptor Vß Repertoire Analysis for Differentiating Multisystem Inflammatory Syndrome in Japanese Children From Toxic Shock Syndrome and Kawasaki Disease.

The specific expansion of T-cell receptor ß chain variable region (TCR-Vß21.3 + ) CD4 + and CD8 + T cells was observed in Japanese patients with multisystem inflammatory syndrome in children. In contrast, these findings were not observed in patients with toxic shock syndrome and Kawasaki disease. T-cell receptor ß chain variable region repertoire analysis to detect specific expansion of Vß21.3 + T cells might be useful for differentiating multisystem inflammatory syndrome in children from toxic shock syndrome and Kawasaki disease.

Safety of Re-dosing Nirsevimab Prior to RSV Season 2 in Children With Heart or Lung Disease.

In children with congenital heart disease and/or chronic lung disease entering their second respiratory syncytial virus (RSV) season, 200 mg nirsevimab had a similar safety profile to that of palivizumab and resulted in nirsevimab serum exposures associated with efficacy in healthy infants, supporting efficacy in this population at risk of severe RSV disease.

Lumicitabine, an orally administered nucleoside analog, in infants hospitalized with respiratory syncytial virus (RSV) infection: Safety, efficacy, and pharmacokinetic results.

Respiratory syncytial virus (RSV) infection is the leading cause of infant hospitalizations and mortality. Lumicitabine, an oral nucleoside analog was studied for the treatment of RSV. The phase 1b and phase 2b studies reported here assessed the safety, pharmacokinetics, and pharmacodynamics of lumicitabine in infants/neonates hospitalized with RSV. In the phase 1b study, infants (≥1 to ≤12 months) and neonates (<28 days) received a single-ascending or multiple-ascending doses (single loading dose [LD] then 9 maintenance doses [MD] of lumicitabine, or placebo [3:1]). In the phase 2b study, infants/children (28 days to ≤36 months old) received lumicitabine 40/20 mg/kg, 60/40 mg/kg LD/MD twice-daily or placebo (1:1:1) for 5 days. Safety, pharmacokinetics, and efficacy parameters were assessed over 28 days. Lumicitabine was associated with a dose-related increase in the incidence and severity of reversible neutropenia. Plasma levels of ALS-008112, the active nucleoside analog, were dose-proportional with comparable mean exposure levels at the highest doses in both studies. There were no significant differences between the lumicitabine groups and placebo in reducing viral load, time to viral non-detectability, and symptom resolution. No emergent resistance-associated substitutions were observed at the RSV L-gene positions of interest. In summary, lumicitabine was associated with a dose-related increase in the incidence and severity of reversible neutropenia and failed to demonstrate antiviral activity in RSV-infected hospitalized infants. This contrasts with the findings of the previous RSV-A adult challenge study where significant antiviral activity was noted, without incidence of neutropenia. Trial registration ClinicalTrials.gov Identifier: NCT02202356 (phase 1b); NCT03333317 (phase 2b).

Clinical significance of serum cytokine profiles for differentiating between Kawasaki disease and its mimickers.

OBJECTIVES: To investigate the clinical significance of serum cytokine profiles for differentiating between Kawasaki disease (KD) and its mimickers. METHODS: Patients with KD, including complete KD, KD shock syndrome (KDSS), and KD with macrophage activation syndrome (KD-MAS), and its mimickers, including multisystem inflammatory syndrome in children, toxic shock syndrome, and Yersinia pseudotuberculosis infection, were enrolled. Serum levels of interleukin (IL)-6, soluble tumor necrosis factor receptor type II (sTNF-RII), IL-10, IL-18, and chemokine (C-X-C motif) ligand 9 (CXCL9) were measured using enzyme-linked immunosorbent assay and compared them with clinical manifestations. RESULTS: Serum IL-6, sTNF-RII, and IL-10 levels were significantly elevated in patients with KDSS. Serum IL-18 levels were substantially elevated in patients with KD-MAS. Patients with KD-MAS and KD mimickers had significantly elevated serum CXCL9 levels compared with those with complete KD. Area under the receiver operating characteristic curve analysis showed that serum IL-6 was the most useful for differentiating KDSS from the others, IL-18 and CXCL9 for KD-MAS from complete KD, and CXCL9 for KD mimickers from complete KD and KD-MAS. CONCLUSION: Serum cytokine profiles may be useful for differentiating between KD and its mimickers.

A registry study of Kawasaki disease patients with coronary artery aneurysms (KIDCAR): a report on a multicenter prospective registry study three years after commencement.

The long-term prognosis of patients with Kawasaki disease (KD) complicated by coronary artery aneurysms (CAA) is still unclear. The present, multicenter registry study aimed to study the factors associated with coronary events (CE) and determine an appropriate management method for patients with KD complicated with CAA. Patients with KD with onset after 2015 and with a medium-sized or large CAA having an actual diameter ≥ 4 mm or a Z-score ≥ 5.0 at 30 days and later after KD onset were included in the annual survey. The primary endpoint was the time-dependent incidence of CE. Associated factors were also examined. In total, 179 patients from 53 centers were enrolled and followed up for a median of 501 days. The median age at KD onset was 2.2 years, 137 patients were male (77%), 47 had incomplete KD (26%), and 36 had large CAA (20%). CE occurred in 13 patients (7%; 95% confidence interval: 4-12%); eight (62%) experienced CE within 1 year, and all the patients experienced a CE within 2 years. All but one patient received antiplatelet drugs and warfarin. Patients with a large CAA had significantly more CAA (2.8 vs. 1.7, p < 0.001), more cases of warfarin use (86% vs. 43%, p < 0.001), and were more likely to have CE (28% vs. 2%, p < 0.001) than those with a medium-sized CAA. On univariate Cox regression analysis, the factors significantly associated with CE were large CAA (hazard ratio (HR): 17.0), three or more CAA (HR: 23.3), and beaded CAA (HR: 15.9). Multivariable Cox regression analysis revealed that the only associated factor was a large CAA. CONCLUSION: Patients with a large CAA were more likely to have a CE within 2 years. Antithrombotic therapy with warfarin did not eliminate the CE risk, and better therapies are desirable. WHAT IS KNOWN: • Coronary artery aneurysms are a serious complication of Kawasaki disease, and coronary events are sometimes fatal. • In previous, retrospective studies in Japan, large aneurysms, male sex, and refractoriness to initial immunoglobulin therapy were considered risk factors for coronary events. WHAT IS NEW: • Of 179 patients with a medium sized or large aneurysm, 13 (7%) experienced coronary events, all of which occurred within 2 years of onset. Factors significantly associated with coronary events were large aneurysms, three or more aneurysms, and beaded aneurysms.

A predictive score for detecting vesicoureteral reflux in children with their first Escherichia coli-induced urinary tract infection.

OBJECTIVES: In children with a first Escherichia coli-induced febrile urinary tract infection (fUTI), routine voiding cytourethrography (VCUG) is not recommended for detecting vesicoureteral reflux (VUR). Meanwhile, the sensitivity of renal and bladder ultrasound (RBUS) for detecting VUR is insufficient. Aiming to implement VCUG properly for children with a first E. coli-induced fUTI, we attempted to construct a predictive scoring system for the early screening of VUR. METHODS: This study enrolled patients aged <2 years of age hospitalized for their first E. coli-induced fUTI during the period when VCUG was implemented for all patients (2007-14, non-selective group [n = 111]) and only for those with VUR-suspected RBUS findings, bacteremia or acute focal bacterial nephritis (2016-19, selective group [n = 102]). We evaluated the accuracy of the current criteria and the VUR predictive score constructed using data from the non-selective group. RESULTS: In the non-selective group, 32 patients had VUR (29%). In the selective group, 20 of 45 VCUG-tested patients had VUR (44%). Among 57 patients not undergoing VCUG in the selective group, 8 had a recurrence of fUTI, 3 of whom were diagnosed with VUR. In the non-selective group, 9 patients with VUR did not fulfill the current criteria and the VUR predictive score consisting of young age, female sex, prolonged fever, hypoproteinemia, hyponatremia and hyperglycemia, showed higher sensitivity, specificity than the current criteria. CONCLUSIONS: The current imaging/bacteriological criteria were ineffective in screening for VUR in patients with their first E. coli-induced fUTI. The VUR predictive score can be an accurate indicator for implementing VCUG.

Severe encephalopathy associated with SARS-CoV-2 Omicron BA.1 variant infection in a neonate.

INTRODUCTION: The coronavirus disease 2019 (COVID-19), including the Omicron variant, is less severe in children than in adults. To date, there has been no detailed description of COVID-19-associated severe encephalopathy due to the Omicron variant during the neonatal and early infantile periods. CASE PRESENTATION: During the outbreak of the Omicron variant, a 29-day-old male presented with a pale and ill appearance. The patient was intubated for mechanical ventilation owing to recurrent apnea, which subsequently turned out to be a breath-holding that may have been caused by seizure. In addition, nonconvulsive status epilepticus was observed. Total duration of repetitive seizure activities was approximately 30 min per hour when seizures were most severe. Brain magnetic resonance imaging (MRI) on day 14 revealed extensive hyperintensity in the T2 sequence, hypointensity in the fluid-attenuated inversion recovery (FLAIR) sequence in the deep and subcortical white matter, and diffusion restriction in the corpus callosum. The Omicron BA.1 variant of the severe acute respiratory syndrome coronavirus 2 was detected in his respiratory sample. Follow-up MRI on day 45 revealed multiple cystic cavitations. CONCLUSION: Although COVID-19 is not severe in most children, life-threatening conditions such as COVID-19-associated severe encephalopathy can occur during the neonatal and early infantile periods.

Incidence and risk factors of acute encephalopathy with biphasic seizures in febrile status epilepticus.

OBJECTIVE: To clarify the incidence and risk factors of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in pediatric patients with febrile status epilepticus (FSE). METHODS: We retrospectively surveyed patients with FSE (≥20 min and ≥40 min) who were younger than 6 years by mailing a questionnaire to 1123 hospitals in Japan. The survey period was 2 years. We then collected clinical data on patients with prolonged febrile seizures (PFS) ≥40 min and those with AESD, and compared clinical data between the PFS and AESD groups. RESULTS: The response rate for the primary survey was 42.3%, and 28.0% of hospitals which had applicable cases responded in the secondary survey. The incidence of AESD was 4.3% in patients with FSE ≥20 min and 7.1% in those with FSE ≥40 min. In the second survey, a total of 548 patients had FSE ≥40 min (AESD group, n = 93; PFS group, n = 455). Univariate analysis revealed significant between-group differences in pH, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase, NH3, procalcitonin (PCT), uric acid, blood urea nitrogen, creatinine (Cr), and lactate. Multivariate analysis using stratified values showed that high PCT was an only risk factor for AESD. A prediction score of ≥3 was indicative of AESD, as determined using the following indexes: HCO3- < 20 mmol/L (1 point), Cl <100 mEq/L (1 point), Cr ≥0.35 mg/dL (1 point), glucose ≥200 mg/dL (1 point), and PCT ≥1.7 pg/mL (2 points). The scoring system had sensitivity of 84.2% and specificity of 81.0%. CONCLUSION: Incidence data and prediction scores for AESD will be useful for future intervention trials for AESD.

Effect of delayed palivizumab administration on respiratory syncytial virus infection-related hospitalisation: A retrospective, observational study.

ABSTRACT: Respiratory syncytial virus (RSV) infection is an important cause of hospitalization in infants and young children. Monthly administration of palivizumab during the RSV season is effective in preventing severe infections in children with comorbidities. However, determining the onset of the RSV season for starting palivizumab is often challenging. The present study aimed to evaluate the ideal timing to start palivizumab and its effect on hospitalization in the real world.We performed a retrospective, observational study to identify the relationship between the timing of the first dose of palivizumab administration and RSV-related hospitalization. Medical records from 2015 to 2019 were reviewed. We included patients who had indications for palivizumab as of July 1 in each year. We counted the proportion of children receiving palivizumab and the number of RSV infection-related hospitalizations each month. We also evaluated the differences in background and underlying disease between children with and without hospitalization.A total of 498 patients were included, and 105 (21.0%) completed the first dose in July when the RSV season usually begins in Japan. Twenty-three (4.6%) patients were hospitalized for RSV infection during the observation period, with 13 (56.5%) hospitalizations before their first dose of palivizumab. The remaining 10 patients were hospitalized after receiving 1 or more doses of palivizumab. Children living with siblings and children with cyanosis originating from congenital heart disease had a higher risk of RSV with odds ratios of 5.1 (95% confidence interval 1.48-17.6, P < .01) and 3.3 (95% confidence interval 1.33-7.94, P < .01), respectively.Delays in administering palivizumab at the beginning of the season increases the rate of RSV infection-related hospitalization. To maximize prophylactic effectiveness, administering the first dose as early as possible in the RSV season is crucial, with priority for cyanotic children or those with siblings.

A phase 3, multicenter, single-arm, open-label study to assess the safety, tolerability, and immunogenicity of a single dose of 13-valent pneumococcal conjugate vaccine in Japanese participants aged 6-64 years who are considered to be at increased risk of pneumococcal disease and who are naive to pneumococcal vaccines.

BACKGROUND: This open-label, single-arm, phase 3 study evaluated safety and immunogenicity of the 13-valent pneumococcal conjugate vaccine (PCV13) in pneumococcal vaccine-naive Japanese individuals aged 6-64 years at increased risk of pneumococcal disease (PD). METHODS: Participants received 1 PCV13 dose. Reactogenicity events were recorded for 7 days (individuals aged 6- to 17-year-old) or 14 days (individuals aged 18 to 64 years old) postvaccination. Adverse events (AEs) were collected for 1 month postvaccination. Opsonophagocytic activity (OPA) and anticapsular immunoglobulin G (IgG) geometric mean concentrations (GMCs) were measured for vaccine serotypes before and 1 month postvaccination. Post hoc analyses compared immunogenicity in participants categorized as at-risk (immunocompetent but having chronic medical conditions associated with increased PD risk) or high-risk (immunocompromised due to diseases/conditions and/or medications). RESULTS: 206 participants aged 6- to 17-year-old (n = 53) and 18 to 64 years old (n = 153) completed the study. Reactogenicity events were generally mild to moderate in severity. AEs were reported in 16% (33/206) of participants; 1.0% (2/206) were severe. Six AEs were vaccine-related; most were associated with local reactions. No serious AEs occurred. Circulating antibody levels for all 13 serotypes increased postvaccination. OPA geometric mean fold rises (GMFRs) from prevaccination to 1 month postvaccination were 5.5-61.7; lower limits of the 2-sided, 95% CI were > 1 for all serotypes. IgG GMFRs were consistent with OPA analyses. In post hoc analyses, 55.8% (115/206) and 44.2% (91/206) of participants were categorized as at risk and at high risk of PD, respectively; OPA GMFRs from prevaccination to 1 month postvaccination were 3.9-635.1, with lower limits of the 2-sided 95% CIs > 1 for all 13 serotypes across these risk groups; IgG GMFRs were consistent with OPA analyses. CONCLUSIONS: PCV13 was well tolerated and immunogenic in Japanese individuals aged 6-64 years considered at increased risk of PD. Results were broadly comparable with past PCV13 studies in other Japanese and non-Japanese populations. Registration number: NCT03571607; JapicCTI-184024.

Kawasaki Disease and Vaccination: Prospective Case-Control and Case-Crossover Studies among Infants in Japan.

The causal effects of vaccines on Kawasaki disease (KD) remain elusive. We aimed to examine the association between vaccines administered during infancy and the development of KD in Japan. We conducted a multicenter prospective case-control study using questionnaires and compared the vaccination status of infants (age: 6 weeks to 9 months) who developed KD (KD group; n = 102) and those who did not develop KD (non-KD group; n = 139). Next, we performed a case-crossover study of 98 cases in the KD group and compared the status of vaccinations between the case and control periods. We also compared the incidence of KD in children for each 5-year period before and after the addition of new vaccines (2012-2013) using data from the Nationwide Survey of KD. In the case-control study, the vaccination status of the KD and control groups did not differ to a statistically significant extent. Multivariable analysis of the vaccination status and patient backgrounds showed no significant association between vaccination and KD development. In the case-crossover study, the status of vaccinations during the case and control periods did not differ to a statistically significant extent. In the analysis of data from the Nationwide Survey of KD, the incidence of KD in children of ages subject to frequent vaccination showed no significant increases in the latter five years, 2014-2018. Based on these prospective analyses, we confirmed that vaccination in early infancy did not affect the risk of KD.

Assessment of Pediatric Admissions for Kawasaki Disease or Infectious Disease During the COVID-19 State of Emergency in Japan.

Importance: The development of Kawasaki disease (KD) has been suggested to be associated with droplet- or contact-transmitted infection; however, its triggers and transmission modes remain to be determined. Under an epidemic of SARS-CoV-2, the COVID-19 state of emergency in Japan served as a nationwide social experiment to investigate the impact of quarantine or isolation on the incidence of KD. Objective: To assess the role of droplet or contact transmission in the etiopathogenesis of KD. Design, Setting, and Participants: This multicenter, longitudinal, cross-sectional study was conducted from 2015 to 2020 at Fukuoka Children's Hospital and 5 adjacent general hospitals. The number of admissions for KD and infectious diseases were analyzed. Participants were pediatric patients admitted to the participating hospitals for KD or infectious diseases. Exposures: Quarantine and isolation owing to the COVID-19 state of emergency. Main Outcomes and Measures: The primary end points were the ratios of patients with KD to patients with respiratory tract or gastrointestinal infections admitted from April to May in 2015 to 2019 and 2020. A Poisson regression model was used to analyze them. Results: The study participants included 1649 patients with KD (median [interquartile range] age, 25 [13-43] months; 901 boys [54.6%]) and 15 586 patients with infectious disease (data on age and sex were not available for these patients). The number of admissions for KD showed no significant change between April and May in 2015 to 2019 vs the same months in 2020 (mean [SD], 24.8 [5.6] vs 18.0 [4.0] admissions per month; 27.4% decrease; adjusted incidence rate ratio [aIRR], 0.73; 95% CI, 0.48-1.10; P = .12). However, the number of admissions for droplet-transmitted or contact-transmitted respiratory tract infections (mean [SD], 157.6 [14.4] vs 39.0 [15.0] admissions per month; 75.3% decrease; aIRR, 0.25; 95% CI, 0.17-0.35; P < .001) and gastrointestinal infections (mean [SD], 43.8 [12.9] vs 6.0 [2.0] admissions per month; 86.3% decrease; aIRR, 0.14; 95% CI, 0.04-0.43; P < .001) showed significant decreases between April and May in 2015 to 2019 vs the same months in 2020 (total, 12 254 infections). Thus, the ratio of KD to droplet- or contact-transmitted respiratory tract and gastrointestinal infections incidence in April and May 2020 was significantly increased (ratio, 0.40 vs 0.12; χ21 = 22.76; P < .001). Conclusions and Relevance: In this study, the significantly increased incidence of KD compared with respiratory tract and gastrointestinal infections during the COVID-19 state of emergency suggests that contact or droplet transmission is not a major route for KD development and that KD may be associated with airborne infections in most cases.

Lipidomics links oxidized phosphatidylcholines and coronary arteritis in Kawasaki disease.

AIMS: Coronary arteritis is a life-threatening complication that may arise in the acute stage of Kawasaki disease (KD), the leading cause of systemic vasculitis in childhood. Various microorganisms and molecular pathogens have been reported to cause KD. However, little is known about the key molecules that contribute to the development of coronary arteritis in KD. METHODS AND RESULTS: To identify causative molecules for coronary arteritis in KD, we prospectively recruited 105 patients with KD and 65 disease controls in four different parts of Japan from 2015 to 2018. During this period, we conducted lipidomics analyses of their sera using liquid chromatography-mass spectrometry (LC-MS). The comprehensive LC-MS system detected a total of 27 776 molecules harbouring the unique retention time and m/z values. In the first cohort of 57 KD patients, we found that a fraction of these molecules showed enrichment patterns that varied with the sampling region and season. Among them, 28 molecules were recurrently identified in KD patients but not in controls. The second and third cohorts of 48 more patients with KD revealed that these molecules were correlated with inflammatory markers (leucocyte counts and C-reactive proteins) in the acute stage. Notably, two of these molecules (m/z values: 822.55 and 834.59) were significantly associated with the development of coronary arteritis in the acute stage of KD. Their fragmentation patterns in the tandem MS/MS analysis were consistent with those of oxidized phosphatidylcholines (PCs). Further LC-MS/MS analysis supported the concept that reactive oxygen species caused the non-selective oxidization of PCs in KD patients. In addition, the concentrations of LOX-1 ligand containing apolipoprotein B in the plasma of KD patients were significantly higher than in controls. CONCLUSION: These data suggest that inflammatory signals activated by oxidized phospholipids are involved in the pathogenesis of coronary arteritis in KD. Because the present study recruited only Japanese patients, further examinations are required to determine whether oxidized PCs might be useful biomarkers for the development of coronary arteritis in broad populations of KD.

Nationwide surveillance of bacterial pathogens isolated from children conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2017: General overview of pathogenic antimicrobial susceptibility.

A nationwide surveillance of the antimicrobial susceptibility of pediatric patients to bacterial pathogens was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in Japan in 2017. The isolates were collected from 18 medical facilities between March 2017 and May 2018 by the three societies. Antimicrobial susceptibility testing was conducted at the central laboratory (Infection Control Research Center, Kitasato University, Tokyo) according to the methods recommended by the Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 926 strains (331 Streptococcus pneumoniae, 360 Haemophilus influenzae, 216 Moraxella catarrhalis, 5 Streptococcus agalactiae, and 14 Escherichia coli). The ratio of penicillin-resistant S. pneumoniae was 0% based on CLSI M100-ED29 criteria. However, three meropenem or tosufloxacin resistant S. pneumoniae isolates were obtained. Among H. influenzae, 13.1% of them were found to be ß-lactamase-producing ampicillin resistant strains, while 20.8% were ß-lactamase non-producing ampicillin-resistant strains. No capsular type b strains were detected. In M. catarrhalis, 99.5% of the isolates were ß-lactamase-producing strains. All S. agalactiae and E. coli strains were isolated from sterile body sites (blood or cerebrospinal fluid). The ratio of penicillin-resistant S. agalactiae was 0%, while that of extended spectrum ß-lactamase-producing E. coli was 14.3%.