Launch of Board Certification in Pediatric Infectious Diseases in Japan.

To cultivate specialists in pediatric infectious diseases (ID) in Japan, the Japanese Society for Pediatric Infectious Diseases initiated board certification for pediatric ID in 2017. Previously, in 2014, we had formed a committee for board certification in pediatric ID and discussed the fundamentals of the board certification system, including the goals, requirements for designated training institutions, provisional certification of pediatric ID specialists and eligibility for and content of the board certification examination. After approval from 31 programs, the pediatric ID programs started in 2017 with 8 fellows in 7 programs. The first 6 graduates received board certification in 2020. To date, 61 pediatricians have been board certified as pediatric ID specialists. In parallel, we introduced board certification for pediatricians who work mainly in primary care settings and have a special interest in pediatric ID. This system has certified 338 pediatricians. During and after the development of the programs, we achieved substantial progress in highlighting the pivotal role of pediatric ID specialists, including the establishment and maintenance of antimicrobial stewardship programs, pediatric ID consultations and introduction of viral diagnosis by polymerase chain reaction at institutions. However, several issues need to be addressed, including the establishment of independent pediatric ID departments in institutions, payment of consultation fees, program site visits, maintenance of certification and cultivation of physician-scientists. These challenges will be the focus of future efforts.

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.

Universal versus risk-based strategies for vaccinating children against COVID-19: Japan and Korea.

The global impact of COVID-19 on children emphasises the need for effective vaccination. While most cases are mild, those with underlying conditions face severe risks. Public health agencies promote various paediatric vaccination approaches. Japan universally recommends vaccination, while Korea prioritises high-risk children. Despite similar healthcare systems, Japan's coverage rates (19%-72%) surpass Korea's (2%-55%). Korea's child death rates are higher, indicating increased risk. Both lack methods to address individual risks, hindering prevention. This study advocates universal vaccination to mitigate future pandemics' impact on children systematically.

Safety and antibody response of the BNT162b2 SARS-CoV-2 vaccine in children aged 5-11 years with underlying diseases: A prospective observational study.

BACKGROUND: Data on the safety and antibody response of the BNT162b2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in children aged 5-11 years with underlying diseases are limited. Thus, our study aimed to address this gap. METHODS: This prospective observational study investigated the antibody titers for SARS-CoV-2 spike protein receptor-binding domain (S-IgG) and nucleocapsid protein (N-IgG) in patients aged 5-11 years with chronic underlying diseases following two doses of BNT162b2. Additionally, a questionnaire was used to assess adverse events (AEs) arising within 7 days after each dose. Data on severe AEs arising within 28 days after each dose were extracted from the patients' electronic medical records. RESULTS: Among 122 patients, 24.6% (30/122) were immunocompromised. Furthermore, 79 patients experienced at least one AE following vaccination, but all recovered without sequelae, including one severe case after the first dose. The seropositivity rate after the second dose was 99.1% (116/117). Excluding 19 N-IgG-positive patients, the geometric mean antibody titer (GMT) was significantly higher in immunocompetent patients than in immunocompromised patients (1496 U/mL [95% confidence interval 1199-1862] vs. 472 U/mL [200-1119], p = 0.035). Additionally, the GMT of S-IgG was higher in N-IgG-positive patients than in N-IgG-negative patients (8203 [5847-11482] U/mL vs. 1127 [855-1486] U/mL, p < 0.001). CONCLUSIONS: BNT162b2 is acceptably safe and immunogenic for children aged 5-11 years with underlying diseases. Although seroconversion was satisfactory in immunocompromised patients, the titers were lower than in immunocompetent patients.

Age dependent discrepancy between SARS-CoV-2 anti-nucleoprotein antibody and anti-RBD spike protein antibody in children reflects vaccine coverage.

BACKGROUND: COVID-19 has become widespread in Japanese children. However, the impact of varying immunization coverage on the seroprevalence of SARS-CoV-2 in children is unknown. METHODS: We examined the SARS-CoV-2 antibody in children aged 0 to 18 who were hospitalized at a university hospital from June 2020 through May 2023. The SARS-CoV-2 anti-nucleoprotein (N) antibody and anti-RBD spike (S) protein antibody was measured. RESULTS: A total of 586 cases were enrolled. The median age was 4 years old (interquartile range 1-9), and 362 (61.8 %) were male. The seroprevalence of anti-S antibodies gradually increased from October 2021 and reached 60 percent by early 2023. The anti-N antibody increased starting in January 2022 and reached 50 percent in May 2023. There was a discrepancy in the seroprevalence of anti-S and N antibodies in children 0 years of age or 12 years and older until the fall of 2022. This discrepancy was minimal for children 1-4 years of age and relatively small in the 5-11-year-old group. DISCUSSION: The data suggests that approximately half of the children in our cohort had been infected with SARS-CoV-2 by May 2023. The discrepancy in seropositivity between the anti-S and N antibodies corresponded to the reported vaccine uptake of each target age group, which suggested protective effects of immunization. However, this effect appeared to diminish after early 2023. CONCLUSION: Age dependent discrepancy between SARS-CoV-2 anti-N and anti-S antibody in children reflected differences in vaccine coverage.

Surgery for long tubular intestinal duplication with massive hemorrhage: a case report and literature review.

BACKGROUND: Long tubular duplication is a rare congenital intestinal disease, that can lead to emergency situations marked by massive hemorrhage. However, preoperative diagnosis and surgical treatment are challenging. This report presents preoperative images and details a surgical procedure for long tubular intestinal duplications with massive hemorrhage. CASE PRESENTATION: A 3-year-old boy presented to the emergency department with melena. Despite undergoing a Tc-99m pertechnetate scintigraphy one year prior, which revealed nonspecific findings with enhancement of some parts of the intestine, enhanced abdominal CT revealed an edematous small intestine with luminal extravasation. The patient received a transfusion of red blood cells; however, his hemoglobin level did not improve. Arterial angiography and double-balloon endoscopy revealed no remarkable findings. Exploratory laparotomy revealed a long tubular duplication in half of the small intestine. Utilizing the Wrenn procedure, we successfully removed all duplicate mucosa. Pathological findings showed that almost all duplications contained gastric mucosa and revealed an ulcer with a ruptured arterial vessel. His symptoms were resolved, and the hemoglobin level stabilized. At 2 months postoperatively, no surgical complications were present. CONCLUSIONS: Effective management of long tubular duplications with massive hemorrhage involves timely application of the Wrenn procedure. Recognition of specific imaging findings is crucial to prompt exploratory laparotomy, ensuring optimal outcomes and preventing delays in treatment.

Aggregated eosinophils and neutrophils characterize the properties of mucus in chronic rhinosinusitis.

BACKGROUND: Airway obstruction caused by viscous mucus is an important pathophysiologic characteristic of persistent inflammation, which can result in organ damage. OBJECTIVE: We investigated the hypothesis that the biophysical characteristics of accumulating granulocytes affect the clinical properties of mucus. METHODS: Surgically acquired nasal mucus samples from patients with eosinophilic chronic rhinosinusitis and neutrophil-dominant, noneosinophilic chronic rhinosinusitis were evaluated in terms of computed tomography density, viscosity, water content, wettability, and protein composition. Isolated human eosinophils and neutrophils were stimulated to induce the formation of extracellular traps, followed by the formation of aggregates. The biophysical properties of the aggregated cells were also examined. RESULTS: Mucus from patients with eosinophilic chronic rhinosinusitis had significantly higher computed tomography density, viscosity, dry weight, and hydrophobicity compared to mucus from patients with noneosinophilic chronic rhinosinusitis. The levels of eosinophil-specific proteins in mucus correlated with its physical properties. Eosinophil and neutrophil aggregates showed physical and pathologic characteristics resembling those of mucus. Cotreatment with deoxyribonuclease and heparin, which slenderizes the structure of eosinophil extracellular traps, efficiently induced reductions in the viscosity and hydrophobicity of both eosinophil aggregates and eosinophilic mucus. CONCLUSIONS: The present study elucidated the pathogenesis of mucus stasis in infiltrated granulocyte aggregates from a novel perspective. These findings may contribute to the development of treatment strategies for eosinophilic airway diseases.

Trend in antibiotic prescription at pediatric primary emergency medical centers in Japan: A multi-center, cross-sectional study.

INTRODUCTION: Antimicrobial resistance is a global issue, and implementation of antimicrobial stewardship programs in outpatient settings is crucial. Japan has also focused on outpatient oral antimicrobial stewardship programs and difficulties in standardizing prescriptions have led to overprescription in primary emergency medical centers. There is a lack of research investigating the antibiotic prescription status of pediatric primary emergency medical centers and the benchmark prescription rates in pediatric outpatient settings. METHODS: We conducted a multi-center, cross-sectional study of seven pediatric primary emergency medical centers located in five prefectures of Japan. We retrospectively extracted data from health claims or directly obtained them from charts at each institution and evaluated trends in the antibiotic prescription rate based on the AWaRe classification between April 2016 and December 2019. RESULTS: Our study included 383,525 encounters, with the most common infectious disease diagnosis being acute upper respiratory tract infection in 93,449 cases (24.4 %). The antibiotic prescription rate during the study period was 7.4 %, representing a decrease of 46 %, from 10.2 % in 2016 to 5.5 % in 2019. The percentage of prescriptions in the Access group increased at all institutions; however, it exceeded 60 % in only three facilities in 2019. The percentage of third-generation cephalosporins varied among facilities, ranging from 1.7 % to 59.4 %, as of 2019. CONCLUSIONS: For pediatric primary emergency medical centers where antimicrobial stewardship programs are implemented, we suggest 5 % as a reasonable benchmark level for the antibiotic prescription rate. Prescribing the antibiotics in the Access groups less frequently remains a domestic challenge in Japan.

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.

Development and validation of a new asthma questionnaire to help achieve a high level of control in school-age children and adolescents.

BACKGROUND: Maintaining good asthma control minimizes the risk of exacerbations and lung function decline and is a primary goal of asthma management. The Japanese Pediatric Asthma Guidelines (JPGL) employs different classification criteria for control status from other guidelines, stressing a higher level of control. Based on JPGL, we previously developed a caregiver-completed questionnaire for assessing and achieving best asthma control in preschoolers. In this study, we aimed to develop a questionnaire for school-age children and adolescents. METHODS: A working questionnaire comprising 14 items for patients and 34 items for caregivers was administered to 362 asthma patients aged 6-15 years and their caregivers. Separately, physicians filled out a questionnaire to determine JPGL-defined control. Logistic regression analysis was performed to construct a model to predict control levels using data from a randomly selected set of completed questionnaires from two-thirds of the subjects. Validation was performed using the remaining questionnaires. RESULTS: A set of 7 questions, encompassing self-assessed control status at the time of the visit and in the past month, and nocturnal/early morning asthma symptoms for patients and frequency of asthma symptoms, dyspnea, rescue beta-agonist use, and asthma hospitalization for caregivers, were selected and the 7-item model showed a good statistical fit with AIC of 110.5. The model has been named the Best Asthma Control Test for School Children and Adolescents (Best ACT-S). Best ACT-S scores differed significantly in the hypothetical direction among the groups of different JPGL-defined control levels, step-up/down treatment decisions, and presence/non-presence of exacerbations in the previous year. CONCLUSIONS: The Best ACT-S is a valid questionnaire for children/adolescents aiming for best asthma control.

Association between use of antipyretics and antibody titers after two doses of the BNT162b2 SARS-CoV-2 vaccine in adolescents and young adults with underlying diseases.

There are few reports on the association between antipyretic use and antibody titers in adolescents and young adults following SARS-CoV-2 vaccination. Multivariable linear regression analyses were performed to examine the association between antipyretic use and antibody titers. The use of antipyretics was not associated with antibody titers (ß coefficient [95% CI] = -0.107 [-0.438 to 0.224]).

Melting temperature mapping method in children: Rapid identification of pathogenic microbes.

INTRODUCTION: The melting temperature (Tm) mapping method (TM) identifies bacterial species by intrinsic patterns of Tm values in the 16S ribosomal RNA gene (16S rDNA) extracted directly from whole blood. We examined potential clinical application of TM in children with bloodstream infection (BSI). METHODS: This was a prospective observational study at a children's hospital in Japan from 2018 to 2021. In patients with diagnosed or suspected BSI, we investigated the match rates of pathogenic bacteria identified by TM and blood culture (BC), the inspection time to identification of TM, and the amount of bacterial DNA in blood samples. RESULTS: The median age of 81 patients (93 samples) was 3.6 years. Of 23 samples identified by TM, 11 samples matched the bacterial species with BC (positive-match rate, 48 %). Of 64 TM-negative samples, 62 samples were negative for BC (negative-match rate, 97 %). Six samples, including one containing two pathogenic bacterial species, were not suitable for TM identification. In total, the matched samples were 73 of 93 samples (match rate, 78 %). There were seven samples identified by TM in BC-negative samples from blood collected after antibiotic therapy. Interestingly, the bacteria were matched with BC before antibiotic administration. These TM samples contained as many 16S rDNA copies as the BC-positive samples. The median inspection time to identification using TM was 4.7 h. CONCLUSIONS: In children with BSI, TM had high negative-match rates with BC, the potential to identify the pathogenic bacteria even in patients on antibiotic therapy, and more rapid identification compared to BC. REGISTERING CLINICAL TRIALS: UMIN000041359https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000047220.

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.

RNA sequencing and target long-read sequencing reveal an intronic transposon insertion causing aberrant splicing.

More than half of cases with suspected genetic disorders remain unsolved by genetic analysis using short-read sequencing such as exome sequencing (ES) and genome sequencing (GS). RNA sequencing (RNA-seq) and long-read sequencing (LRS) are useful for interpretation of candidate variants and detection of structural variants containing repeat sequences, respectively. Recently, adaptive sampling on nanopore sequencers enables target LRS more easily. Here, we present a Japanese girl with premature chromatid separation (PCS)/mosaic variegated aneuploidy (MVA) syndrome. ES detected a known pathogenic maternal heterozygous variant (c.1402-5A>G) in intron 10 of BUB1B (NM_001211.6), a known responsive gene for PCS/MVA syndrome with autosomal recessive inheritance. Minigene splicing assay revealed that almost all transcripts from the c.1402-5G allele have mis-splicing with 4-bp insertion. GS could not detect another pathogenic variant, while RNA-seq revealed abnormal reads in intron 2. To extensively explore variants in intron 2, we performed adaptive sampling and identified a paternal 3.0 kb insertion. Consensus sequence of 16 reads spanning the insertion showed that the insertion consists of Alu and SVA elements. Realignment of RNA-seq reads to the new reference sequence containing the insertion revealed that 16 reads have 5' splice site within the insertion and 3' splice site at exon 3, demonstrating causal relationship between the insertion and aberrant splicing. In addition, immunoblotting showed severely diminished BUB1B protein level in patient derived cells. These data suggest that detection of transcriptomic abnormalities by RNA-seq can be a clue for identifying pathogenic variants, and determination of insert sequences is one of merits of LRS.

Clinical and Laboratory Diagnosis of Exanthems Among Japanese Children Younger Than 6 Years Old in the Post-Measles-Rubella Vaccine Era.

BACKGROUND: Exanthems are a common reason for visits to the pediatric emergency department. However, epidemiological data in the post-measles-rubella vaccine era is limited. OBJECTIVE: We sought to determine the recent causes of exanthems in children younger than 6 years old in the pediatric emergency department. METHODS: A prospective single-center study was conducted in Japan from August 2019 to March 2020. Children younger than 6 years old with exanthems were enrolled. Exanthems were classified into 7 morphological patterns. Varicella, herpes zoster, impetigo, urticaria and Kawasaki disease were diagnosed clinically. Nasopharyngeal swab specimens were collected from patients with nonspecific exanthems and evaluated by polymerase chain reaction (PCR) assays capable of detecting 24 pathogens. The final diagnosis was made by discussion of 3 physicians based on clinical course and microbiology. RESULTS: There were 9705 pediatric visits, of which 296 (3%) had exanthems and were younger than 6 years old. Clinical diagnosis was possible for 160 (54%), including urticaria in 110 (37%), Kawasaki disease in 29 (10%), impetigo in 10 (3%), varicella or herpes zoster in 7 (2%) and group A Streptococcus in 4 (1%). Among the remaining 136 (46%) children, 75 (25%) underwent testing by PCR. One or more pathogens were detected in 49 (65%), specifically enterovirus in 14 (19%), cytomegalovirus in 13 (17%), human herpesvirus type-6 in 12 (16%), adenovirus in 11 (15%) and human herpesvirus type-7 in 8 (11%). Final infectious disease diagnoses were roseola infantum in 11 (15%), enterovirus in 9 (12%), adenovirus in 6 (8%), mixed virus infection in 5 (7%), group A Streptococcus in 3 (4%), parechovirus-A in 3 (4%) and influenza in 3 (4%). CONCLUSIONS: The most common causes of pediatric exanthems were noninfectious diseases and viral exanthema. PCR assay was instrumental for etiological diagnosis of nonspecific exanthems.

Guidelines for the Management of Respiratory Infectious Diseases in Children in Japan 2022.

The members of the Japanese Society for Pediatric Infectious Diseases and the Japanese Society of Pediatric Pulmonology have developed Guidelines for the Management of Respiratory Infectious Diseases in Children with the objective of facilitating appropriate diagnosis, treatment and prevention of respiratory infections in children. The first edition was published in 2004 and the fifth edition was published in 2022. The Guideline 2022 consists of 2 parts, clinical questions and commentary, and includes general respiratory infections and specific infections in children with underlying diseases and severe infections. This executive summary outlines the clinical questions in the Guidelines 2022, with reference to the Japanese Medical Information Distribution Service Manual. All recommendations are supported by a systematic search for relevant evidence and are followed by the strength of the recommendation and the quality of the evidence statements.

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.

Clinical efficacy of remdesivir for COVID-19 in children: A propensity-score-matched analysis.

Clinical efficacy of remdesivir in children with COVID-19 is unclear. This propensity-score-matched retrospective cohort study of children with COVID-19 showed that the rate of patients achieving defervescence on Day 4 was higher in the remdesivir group than in the non-remdesivir group, but was not statistically different (86.7% vs 73.3%, P = 0.333).

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.