Nationwide epidemiology and health resource use among children with COVID-19 in Japan.

BACKGROUND: The COVID-19 pandemic posed substantial challenges to healthcare systems. Understanding the responses of pediatric health services is crucial for future pandemic planning and preparedness, yet such data remains limited. METHODS: In this retrospective cohort study, we analyzed data from administrative databases developed by Japan Medical Data Center and DeSC Healthcare Inc. The dataset comprised records of 2,612,511 children, totaling 60,224,888 person-months, from January 2020 to May 2022. Multivariate generalized estimation equations were used to examine the incidence rates of COVID-19 and associated health resource use. RESULTS: Our analysis revealed that the incidence rates of COVID-19 gradually increased from Wave I (2.2 cases per 100,000 person-months) to Wave V (177.8cases per 100,000 person-months), with a notable elevation during Wave VI (2367.7 cases per 100,000 person-months). While nucleic acid amplification tests were primarily used during Waves I-V, the use of rapid antigen tests markedly increased in Wave VI. The hospitalization rates increased gradually from 0.2 in Wave I to 10.2 events per 100,000 person-months in Wave VI, and the case-hospitalization risk decreased from 14.9% in Wave II to 0.7% in Wave VI. Additionally, we observed decreasing trends in the use of antibiotics (Wave I, 31.8%; Wave VI, 9.0%), whereas antipyretic use rose from Wave I (56.1%) to Wave VI (86.6%). CONCLUSIONS: Our study highlighted essential changes in the nationwide pediatric healthcare system's response to the COVID-19 pandemic. These findings provide valuable insights into the future pandemic planning and preparedness.

Structural and organizational determinants of the capacity for COVID-19 testing and diagnoses in children: Insights from the 2009 influenza and COVID-19 pandemics.

BACKGROUND: This study explored factors associated with testing and diagnoses for children with COVID-19 at the hospital level and investigated whether the capacity of testing and diagnoses during the 2009 influenza pandemic was associated with that during COVID-19 pandemic. METHODS: In this observational study, we analyzed data obtained from the Japan Medical Data Center database, comprising 4906 medical facilities and 1.7 million infectious disease-related visits among children aged <20 years in 2020-2021. Multivariable generalized linear models were used to explore determinants of testing and diagnoses capacity for COVID-19 and investigate the association between the capacity during the 2009 influenza and COVID-19 pandemics. RESULTS: Public hospitals (adjusted incidence rate ratio [aIRR], 1.52; 95%CI, 1.26-1.82) and university hospitals (aIRR, 1.44; 95%CI, 1.14-1.80) were more likely to perform testing for COVID-19 among children, compared to clinics. The highest testing rate was observed in the department of internal medicine (aIRR, 1.64; 95%CI, 1.32-2.04), followed by pediatrics (aIRR, 1.40; 95%CI, 1.10-1.78) and otolaryngology (aIRR, 1.21; 95%CI, 0.89-1.64). Cubic spline models demonstrated the dose-response relationships between testing rate for influenza in 2009 and testing rates for COVID-19. Compared to the medical facilities in the lowest quartile of testing rate for influenza in 2009, those in the highest quartile were more likely to perform testing for COVID-19 (aIRR, 1.62; 95%CI, 1.43-1.83). CONCLUSIONS: Our study provides insights into the capacity of testing and diagnoses for children, highlighting the dose-response relationship between the 2009 influenza and COVID-19 pandemics, which could be valuable in preparing healthcare systems for future pandemics.

Infection prevention measures and its determinants in childcare facilities during the COVID-19 pandemic: A nationwide survey (2022-2023).

BACKGROUND: The coronavirus disease-2019 (COVID-19) pandemic presented an unprecedented challenge to societies, necessitating adaptations in infection prevention measures. While there is ample data on infection prevention practices in workplace and healthcare settings, comprehensive data specific to childcare facilities has been lacking. METHODS: We conducted a nationwide web-based survey capturing responses from various childcare facilities (N = 549). This aimed to understand the adaptation in infection prevention measures between fiscal years 2022 and 2023, the status of events and activities, and the factors influencing decision-making related to infection prevention. RESULTS: From 2022 to 2023, most childcare facilities reduced infection prevention practices like mandatory mask-wearing (46.9 %-7.5 %) and eating without conversing (56.5 %-7.4 %), whereas they continued high levels of hand sanitization and checking child's health condition before attendance. The frequency of events and activities (e.g., athletic meets, field trips) increased, with many being held without restrictions. Surprisingly, 62.8 % of facilities used items not recommended for infection prevention. The influence of local government guidelines (risk ratio, 0.69; 95%CI, 0.53-0.90) and the input from junior teachers (risk ratio, 0.85; 95%CI, 0.72-0.99) were associated with reduced risk of using inappropriate items. Furthermore, childcare facilities emphasized the need to collaborate with public health and medical professionals for more accurate and efficient decision-making during pandemics. CONCLUSIONS: The survey provides insights into the evolving practices of Japanese childcare facilities during the COVID-19 pandemic. It underscores the importance of refining information sources, enhancing decision-making processes, and fostering collaboration with the medical community for future pandemics and natural disasters.

Clinical Practice Patterns, Health Resource Use and Risk Factors for Severe Conditions Among Children Hospitalized With COVID-19 in Japan.

BACKGROUND: The trends in clinical practice patterns and health resource use, as well as risk factors for severe conditions among children hospitalized with coronavirus disease-2019 (COVID-19), remain unclear. MATERIALS AND METHODS: We conducted a retrospective observational study consisting of 9876 children hospitalized with COVID-19 during 2020-2022 using the Medical Data Vision database in Japan. We investigated trends in patient characteristics, health resource use, treatment patterns and laboratory data. Additionally, log-binomial regression models were used to investigate the risk factors associated with severe COVID-19 among pediatric inpatients with COVID-19. RESULTS: We observed decreasing trends in the lengths of hospital stays, healthcare costs, computed tomography use, and antibiotic use, and increasing trends in treatment with intravenous hydration and use of antipyretics, antiepileptics, antiemetics and antivirals from the first wave to the seventh wave of COVID-19 pandemic. During the 3-year period, the risk of severe COVID-19 was almost stable at 3%. Risk factors associated with severe COVID-19 were children less than 1 year old [risk ratio (RR): 1.69; 95% confidence interval (CI): 1.02-2.78], the number of complex chronic diseases (RR for 1 disease: 4.49; 95% CI: 2.76-7.32; RR for 2 or more diseases: 10.2; 95% CI: 5.19-20.3) and asthma (RR: 1.84; 95% CI: 1.06-3.20). CONCLUSIONS: Our study observed the changes in practice patterns and health resource use for children hospitalized with COVID-19 and identified risk factors associated with severe COVID-19. These findings indicate the importance of vigilant monitoring and tailored treatment strategies in children with these risk factors.

Clinical Practice Patterns and Risk Factors for Severe Conditions in Pediatric Hospitalizations With Respiratory Syncytial Virus in Japan: A Nationwide Analyses (2018-2022).

BACKGROUND: Respiratory syncytial virus (RSV) represents a global health challenge, especially among younger children. While the disease burden in Japan has been preliminarily quantified, there remains a lack of comprehensive understanding regarding treatment patterns and the influence of known risk factors at a national scale. MATERIALS AND METHODS: We conducted a retrospective cohort study consisting of 50,482 children under 5 years hospitalized with RSV infections during 2018-2022 using the Medical Data Vision database. We investigated trends in patient characteristics, health resource use, treatment patterns, and laboratory data. Additionally, multivariable modified Poisson regression models were used to investigate the risk factors associated with severe conditions. RESULTS: We observed an increasing trend in the inpatient healthcare costs and decreasing trends in the use of antibiotics, bronchodilators, systemic corticosteroids and other symptomatic medications from 2018 to 2022. Risk factors associated with severe RSV infections were children less than 1 year (risk ratio, 2.90; 95% CI: 2.53-3.32) and the number of complex chronic diseases (risk ratio for 1 disease, 2.68; 95% CI: 2.34-3.06: risk ratio for 2 or more diseases, 6.91; 95% CI: 5.81-8.21). Annual inpatient healthcare costs for RSV infections were estimated at 11-14 billion Japanese Yen for younger children. CONCLUSIONS: Our study observed the changes in practice patterns and health resource use for children hospitalized with RSV infections and identified risk factors associated with severe conditions. These findings provide insights for policymakers and clinicians aiming to devise strategies for further improving clinical practices, including newly developed vaccines and single-dose long-acting monoclonal antibodies.

Successful use of dupilumab for egg-induced eosinophilic gastroenteritis with duodenal ulcer: a pediatric case report and review of literature.

BACKGROUND: Non-esophageal eosinophilic gastrointestinal disorder (non-EoE-EGID) is a rare disease in which eosinophils infiltrate parts of the gastrointestinal tract other than the esophagus; however, the number of patients with non-EoE-EGID has been increasing in recent years. Owing to its chronic course with repeated relapses, it can lead to developmental delays due to malnutrition, especially in pediatric patients. No established treatment exists for non-EoE-EGID, necessitating long-term systemic corticosteroid administration. Although the efficacy of dupilumab, an anti-IL-4/13 receptor monoclonal antibody, for eosinophilic esophagitis, has been reported, only few reports have demonstrated its efficacy in non-EoE EGIDs. CASE PRESENTATION: A 13-year-old boy developed non-EoE-EGID with duodenal ulcers, with chicken eggs as the trigger. He was successfully treated with an egg-free diet, proton pump inhibitors, and leukotriene receptor antagonists. However, at age 15, he developed worsening upper abdominal pain and difficulty eating. Blood analysis revealed eosinophilia; elevated erythrocyte sedimentation rate; and elevated levels of C-reactive protein, total immunoglobulin E, and thymic and activation-regulated chemokines. Upper gastrointestinal endoscopy revealed a duodenal ulcer with marked mucosal eosinophilic infiltration. Gastrointestinal symptoms persisted even after starting systemic steroids, making it difficult to reduce the steroid dose. Subcutaneous injection of dupilumab was initiated because of comorbid atopic dermatitis exacerbation. After 3 months, the gastrointestinal symptoms disappeared, and after 5 months, the duodenal ulcer disappeared and the eosinophil count decreased in the mucosa. Six months later, systemic steroids were discontinued, and the duodenal ulcer remained recurrence-free. The egg challenge test result was negative; therefore, the egg-free diet was discontinued. Blood eosinophil count and serum IL-5, IL-13, and eotaxin-3 levels decreased after dupilumab treatment. The serum levels of IL-5 and eotaxin-3 remained within normal ranges, although the blood eosinophil counts increased again after discontinuation of oral prednisolone. CONCLUSIONS: Suppression of IL-4R/IL-13R-mediated signaling by dupilumab may improve abdominal symptoms and endoscopic and histologic findings in patients with non-EoE-EGID, leading to the discontinuation of systemic steroid administration and tolerance of causative foods.

Roles of Oxidative Injury and Nitric Oxide System Derangements in Kawasaki Disease Pathogenesis: A Systematic Review.

Kawasaki disease (KD) is an acute febrile vasculitis that occurs mostly in children younger than five years. KD involves multiple intricately connected inflammatory reactions activated by a cytokine cascade. Despite therapeutic advances, coronary artery damage may develop in some patients, who will be at risk of clinical cardiovascular events and even sudden death. The etiology of KD remains unclear; however, it may involve both genetic and environmental factors leading to aberrant inflammatory responses. Given the young age of onset, prenatal or perinatal exposure may be etiologically relevant. Multisystem inflammatory syndrome in children, a post-infectious hyper-inflammatory disorder associated with severe acute respiratory syndrome coronavirus 2, has features that overlap with those of KD. Available evidence indicates that vascular endothelial dysfunction is a critical step in the sequence of events leading to the development of cardiovascular lesions in KD. Oxidative stress and the dysregulation of the nitric oxide (NO) system contribute to the pathogenesis of inflammatory responses related to this disease. This review provides current evidence and concepts highlighting the adverse effects of oxidative injury and NO system derangements on the initiation and progression of KD and potential therapeutic strategies for cardiovascular pathologies in affected children.

Association of Yersinia Infection With Kawasaki Disease: A Prospective Multicenter Cohort Study.

BACKGROUND: Yersinia infection is known to present with Kawasaki disease (KD)-like symptoms although differentiating the 2 has been a challenge. The present study aimed to describe the clinical characteristics and prevalence of Yersinia infection presenting with KD-like symptoms. METHODS: The present, prospective, multicenter study enrolled patients who received a diagnosis of KD between January 2021 and January 2022 at 2 hospitals in Tokyo. Stool samples were collected within 3 days of the start of KD treatment, and cultures were performed for Yersinia . Clinical history and symptoms suggestive of Yersinia infection were also evaluated. RESULTS: During the study period, 141 KD patients were screened and 117 patients with evaluable stool samples were registered. Only 1 patient was positive for Yersinia pseudotuberculosis , which was detected from both stool and blood cultures. The patient was refractory to KD treatment but improved after initiation of appropriate antibiotic therapy. CONCLUSIONS: Routine screening for Yersinia is not appropriate for patients with KD and should be limited to certain patients in high-risk areas and those who are refractory to the standard KD treatment.

Impacts of routine varicella vaccination program and COVID-19 pandemic on varicella and herpes zoster incidence and health resource use among children in Japan.

PURPOSE: To determine the epidemiological trends in pediatric varicella and herpes zoster incidence and changes in healthcare resource use from 2005 to 2022 using a nationally representative database in Japan. MATERIALS AND METHODS: We conducted a retrospective observational study consisting of 3.5 million children with 177 million person-months during 2005-2022 using Japan Medical Data Center (JMDC) claims database in Japan. We investigated trends in incidence rates of varicella and herpes zoster and changes in healthcare resource use (e.g., antiviral use, office visits, and healthcare costs) over 18 years. Interrupted time-series analyses were used to investigate the impact of the routine varicella vaccination program in 2014 and infection prevention measures against COVID-19 on incidence rates of varicella and herpes zoster and related healthcare utilization. RESULTS: After the introduction of the routine immunization program in 2014, we observed level changes in incidence rates (45.6 % reduction [95 %CI, 32.9-56.0] of varicella cases, antiviral use (40.9 % reduction [95 %CI, 25.1-53.3]), and relevant healthcare costs (48.7 % reduction [95 %CI, 38.2-57.3]). Furthermore, infection prevention measures against COVID-19 were associated with additional level changes in varicella rates (57.2 % reduction [95 %CI, 44.5-67.1]), antiviral use (65.7 % reduction [59.7-70.8]), and healthcare costs (49.1 % [95 %CI, 32.7-61.6]). In contrast, the changes in incidence and healthcare costs for herpes zoster were relatively small, which showed 9.4 % elevated level change with a decreasing trend and 8.7 % reduced level change with a decreasing trend after the vaccine program and the COVID-19 pandemic. The cumulative incidence of herpes zoster in children born after 2014 was lower than that before 2014. CONCLUSIONS: Varicella incidence and healthcare resource use were largely affected by the routine immunization program and infection prevention measures against COVID-19, while these impacts on herpes zoster were relatively small. Our study indicates that immunization and infection prevention measures largely changed pediatric infectious disease practices.

Nationwide epidemiology and clinical practice patterns of pediatric urinary tract infections: application of multivariate time-series clustering.

BACKGROUND: The nationwide epidemiology and clinical practice patterns for younger children hospitalized with urinary tract infections (UTIs) were unclear. METHODS: We conducted a retrospective observational study consisting of 32,653 children aged < 36 months who were hospitalized with UTIs from 856 medical facilities during fiscal years 2011-2018 using a nationally representative inpatient database in Japan. We investigated the epidemiology of UTIs and changes in clinical practice patterns (e.g., antibiotic use) over 8 years. A machine learning algorithm of multivariate time-series clustering with dynamic time warping was used to classify the hospitals based on antibiotic use for UTIs. RESULTS: We observed marked male predominance among children aged < 6 months, slight female predominance among children aged > 12 months, and summer seasonality among children hospitalized with UTIs. Most physicians selected intravenous second- or third-generation cephalosporins as the empiric therapy for treating UTIs, which was switched to oral antibiotics during hospitalizations for 80% of inpatients. Whereas total antibiotic use was constant over the 8 years, broad-spectrum antibiotic use decreased gradually from 5.4 in 2011 to 2.5 days of therapy per 100 patient-days in 2018. The time-series clustering distinctively classified 5 clusters of hospitals based on antibiotic use patterns and identified hospital clusters that preferred to use broad-spectrum antibiotics (e.g., antipseudomonal penicillin and carbapenem). CONCLUSIONS: Our study provided novel insight into the epidemiology and practice patterns for pediatric UTIs. Time-series clustering can be useful to identify the hospitals with aberrant practice patterns to further promote antimicrobial stewardship. A higher resolution version of the Graphical abstract is available as Supplementary information.

Trends in Influenza and Related Health Resource Use During 2005-2021 Among Children in Japan.

BACKGROUND: To determine the epidemiological trends in pediatric influenza and changes in healthcare resource use from 2005 to 2021 using nationally representative outpatient database in Japan. METHODS: We conducted a retrospective cohort study consisting of 3.5 million children with 177 million person-months during 2005-2021 using Japan Medical Data Center claims database in Japan. We investigated trends in incidence rates of influenza and changes in healthcare resource use (eg, use of antivirals) over 17 years. Generalized estimation equations were used to investigate the impact of the 2009 influenza pandemic and the coronaviral disease 2019 (COVID-19) pandemic on incidence rates of influenza and related healthcare utilization. RESULTS: Annual incidence rates of influenza were estimated at 55 cases per 1000 person-years with a 93% relative increase [95% confidence interval (CI): 80%-107%] during the 2009 influenza pandemic and a 99.4% relative reduction (95% CI: 99.3%-99.4%) during the COVID-19 pandemic. Similar patterns were observed for health resource use, total healthcare costs, admission rates and antiviral agent use. Approximately 80% of children with influenza received prescriptions for antivirals. The most prescribed antivirals were oseltamivir, but we observed a temporal increase in zanamivir use during 2007-2009, an increasing trend in laminamivir use during 2010-2017, a temporal increase in baloxavir use in 2018. Symptomatic medications with serious side effects (codeine, salicylate, sedative antihistamine) showed decreasing trends over the study period. CONCLUSIONS: Influenza incidence and healthcare resource use were largely affected by the 2009 influenza pandemic and the COVID-19 pandemic. Our study indicates improvement of quality in healthcare delivered to children.

Current Prevalence of Antimicrobial Resistance in Okayama from a National Database between 2018 and 2021.

Antimicrobial resistance is an emerging global threat that must be addressed using a multidisciplinary approach. This study aimed to raise awareness of high-level antimicrobial-resistant (AMR) pathogens in Japan by comparing their recent prevalences among prefectures, particularly Okayama. Data for the isolation proportions of meropenem-resistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, cefotaxime-resistant Escherichia coli and Klebsiella pneumoniae, and levofloxacin-resistant E. coli and K. pneumoniae were collected from the Japan Nosocomial Infections Surveillance, a national database sponsored by the Japanese Ministry of Health, Labour, and Welfare, between 2018 and 2021. The average isolated proportions of the seven AMR pathogens were higher in Okayama compared to other prefectures: the worst (19.9%) was meropenem-resistant P. aeruginosa, the sixth worst (57.2%) was methicillin-resistant S. aureus, the eighth worst (3.3%) was vancomycin-resistant E. faecium, the second (37.8%) and fifth worst (17.6%) were cefotaxime-resistant E. coli and K. pneumoniae, respectively, and the fourth (49.9%) and third worst (8.7%) were levofloxacin-resistant E. coli and K. pneumoniae, respectively. Our study highlights the notably high prevalences of representative AMR pathogens in Okayama, suggesting the need for fundamental infection prevention and control by healthcare professionals, promoting antimicrobial stewardship, and educating undergraduates and postgraduates in Okayama.

Successful TCRαß/CD19-Depleted Hematopoietic Cell Transplantation for a Patient With Artemis Deficiency.

Artemis deficiency is characterized by DNA double-strand breaks repairing dysfunction and increased sensitivity to ionizing radiation and alkylating reagents. We describe the first successful case of T-cell receptor [TCR]αß/CD19-depleted hematopoietic cell transplantation [HCT] for Artemis deficiency in Japan. A 6-month-old Korean boy was diagnosed with Artemis-deficient severe combined immunodeficiency. He had no human leukocyte antigen (HLA)-matched sibling or unrelated donor. Therefore, TCRαß/CD19-depleted HCT from his haploidentical mother was performed. Despite mixed chimerism in whole blood, T cells achieved complete donor chimerism 6 months after HCT. TCRαß/CD19-depleted HCT could be an effective treatment for patients with radiation-sensitive severe combined immunodeficiency.

Natto intake is a risk factor of Bacillus subtilis bacteremia among children undergoing chemotherapy for childhood cancer: A case-control study.

BACKGROUND: Natto, a popular, daily food in Japan, is made from soybeans fermented by Bacillus subtilis. The aim of this retrospective case-control study (matched 1: 4) is to determine whether natto intake is a risk factor of B. subtilis bacteremia in this population. METHODS: The retrospective, matched case-control study was conducted at Tokyo Metropolitan Children's Medical Center between April 2012 and June 2020 and included pediatric patients younger than 15 years who received chemotherapy for cancer. Patients who received hematopoietic stem cell transplantation were excluded. Patients with B. subtilis bacteremia were compared with controls matched for age and underlying diseases. Dietary information within seven days from the date of blood culture collection was extracted from medical records. Multivariate logistic regression was performed to define the risk factors of B. subtilis bacteremia. RESULTS: In total, 23 patients with B. subtilis bacteremia were identified and matched to 92 controls. The percentage of patients and controls who ingested natto within seven days from the date of blood culture collection was 78% and 50%, respectively. On univariate analysis, the odds ratio of natto intake for B. subtilis bacteremia was 3.6 (95% confidence interval [CI]: 1.2-10.5). Multivariable logistic regression tests after controlling for neutropenia revealed that B. subtilis bacteremia was associated significantly with natto intake at odds ratio 3.3 (95% CI: 1.1-9.6). CONCLUSION: Natto intake was associated with B. subtilis bacteremia during chemotherapy for childhood cancer.

Clinical characteristics and treatment of IMP-type carbapenemase-producing Enterobacteriaceae bacteremia: Case series and literature review.

BACKGROUND: Several carbapenemases have been identified globally in Enterobacteriaceae. In Japan, IMP-type carbapenemase is the most prevalent, although cases of carbapenemase-producing Enterobacteriaceae (CPE) bacteremia are still scarce. The present case series and literature review aimed to elucidate the clinical characteristics and treatment strategies for IMP-type CPE bacteremia. METHODS: Clinical data on pediatric cases of IMP-type CPE bacteremia at the Tokyo Metropolitan Children's Medical Center between 2010 and 2020 were collected, and a review of past studies of IMP-type CPE bacteremia has been provided. RESULTS: Five pediatric episodes of IMP-type CPE bacteremia were identified. Our review of previous literature on IMP-type CPE bacteremia revealed 24 adult patients, but no pediatric patients. All 29 cases had underlying diseases, and 23 (79%) received combination therapy. The median duration of antibiotic therapy was 14 days (interquartile range: 9-14 days). The overall mortality rate was 38% (11/29). The mortality rates associated with monotherapy and combination therapy were 67% (4/6) and 30% (7/23), respectively. CONCLUSIONS: We report the first case series of IMP-type CPE bacteremia in children. Our review of past studies suggests that combination therapy might lead to better survival outcomes in patients with IMP-type CPE bacteremia. Further research is needed to establish an optimal treatment strategy for IMP-type CPE bacteremia.