After the outbreak of COVID-19, the epidemiology of different pathogens causing childhood respiratory infections in different geographical regions around the world has changed, and the similar changes have occurred in China. These changes have greatly increased the difficulties in preventing and treating pediatric respiratory infections in clinical practice. Therefore, this paper aims to summarize the epidemiological changes of different pathogens in children with respiratory tract infection after the epidemic, in order to provide some ideas for the precise prevention and treatment of the disease.

Objective To understand the prevalence of respiratory syncytial virus (RSV) and co-positivity of other pathogens before, during and after COVID-19 pandemic, and to provide evidence-based support for improving the prevention and treatment of acute respiratory tract infections (ARTIs) in children. Methods The pathogen detection results of ARTIs children aged ≤16 years who were admitted to the Children's Hospital of Soochow University from January 2016 to May 2024 were retrospectively analyzed. The characteristics of RSV epidemics and mixed positivity for other pathogens in the first year of the COVID-19 epidemic (2020, Stage Ⅰ), the second and third years (2021-2022, Stage Ⅱ) and the post-COVID-19 epidemic (January 2023 to May 2024, Stage Ⅲ) were compared with those in the pre-epidemic period. Results The study included 83356 children with ARTIs, with 11277 (13.5%) testing positive for RSV, 5605 (6.7%) testing positive for RSV alone, and 5672 (6.8%) testing positive for RSV in combination with other respiratory pathogens. In RSV positive children, the detection rates of bacteria, other viral pathogens and atypical pathogens were 39.5%, 13.6% and 5.7%, respectively. RSV test positive rates decreased in 2020 and 2022, while RSV test positive rates increased in 2021, 2023 and 2024 compared with predicted positive rates. There were significant differences in age, epidemic period and season between single RSV positive group and mixed RSV positive group (P<0.001). In stage Ⅲ, the positive rate of RSV mixed with other pathogens was significantly higher than that of single RSV, and the difference was statistically significant (P<0.01). The detection rate of influenza A/B viruses, human parainfluenza virus, adenovirus, human metapneumovirus, Mycoplasma pneumoniae, Chlamydia pneumoniae and Haemophilus influenzae was significantly higher in children with RSV. Conclusions The COVID-19 pandemic had an adverse impact on the prevalence of RSV and the diagnosis and treatment of mixed-positive cases of other pathogens, and the resurgence of mixed-positive RSV and the escalation of infections should be monitored for a long time after COVID-19.

Objective To explore the risk factors of death from influenza A (H1N1)-associated encephalopathy (IAE) in children, and to provide evidence for early clinical diagnosis and intervention. Methods The clinical data of children with H1N1 IAE admitted to the hospital from January 2014 to December 2020 were retrospectively analyzed, and they were divided into the survival group and the death group according to prognosis. The risk factors associated with death in children with H1N1 IAE were analyzed by binary logistic regression. Results A total of 59 children (39 boys and 20 girls) with H1N1 IAE were included. The median age was 42 (21-73) months, and 66.1% (39/59) of the children were <5 years old. The median time between the onset of neurological symptoms and fever was 1 (0.5-2) days. Thirty-three patients (55.9%) had severe pneumonia and respiratory failure, and 1 of them had plastic bronchitis. Fifty-eight children were treated with oseltamivir. The median time from onset to use of anti-influenza drugs was 2 (1-4) days. Forty-eight patients were discharged from hospital with improvement and 11 died (18.6%). The median time from admission to death was 3 (1-5) days. Compared with the survival group, the death group presented higher incidences of consciousness disorder, respiratory failure, and brain herniation, a greater proportion of cases requiring mechanical ventilation treatment, a higher neutrophil count, elevated levels of procalcitonin, blood glucose, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, a longer prothrombin time, a higher ratio of abnormal head CT findings, and a lower monocyte count. All the differences were statistically significant (P<0.05). The results of binary logistic regression analysis revealed that elevated neutrophil count and lactate dehydrogenase levels might be associated with the occurrence of death in children with H1N1 IAE (P<0.05). Conclusions For children with H1N1 IAE, the risk of death may increase with elevated neutrophil counts and lactate dehydrogenase levels.

Objective To analyze the epidemiological characteristics of human bocavirus (HBoV) in hospitalized children with acute respiratory tract infections, and to provide evidence for the diagnosis and prevention of acute respiratory infection in children. Methods A retrospective analysis was conducted on the etiological test data of sputum or bronchoalveolar lavage fluid from children hospitalized due to acute respiratory tract infections in a hospital in Shijiazhuang from March 2021 to February 2024. Detection was carried out using a multiplex detection kit for 13 respiratory pathogens. The epidemiological characteristics of HBoV, including population distribution and seasonal distribution, were described and analyzed. Results The total detection rate of HBoV was 3.73% (1315/35220), with a higher detection rate in male (3.91%) than in female (3.49%) (χ²=4.08, P<0.05). The detection rate is highest in the 1- <3 years old group (9.25%, 722/7805), followed by the 3- <6 years old group (3.42%, 362/10585). There was a statistically significant difference in detection rates among different age groups (χ²=989.15, P<0 001). The detection rate of HBoV varied in different years. The highest detection rate was in 2021 - 2022 (5.20%, 443/8519), and the lowest was in 2022 - 2023 (2.22%, 204/9195), with a statistically significant difference (χ²=110.02, P<0.001). During the study period, the highest detection rate was 8.56% (823/9610) in summer, followed by 3.15% (276/8773) in autumn. And there was a statistically significant difference detection rates among different seasons(χ²=939.36, P<0.001). Among the patients with HBoV infection detected, 557 cases had no other pathogens detected, while 758 cases were co-infected with at least one other pathogenic microorganism. Conclusions HBoV is a common pathogen of acute respiratory infections in children in Shijiazhuang. It is more common in children aged 1- <3 in summer and autumn, with more males than females. It is often co-detected with other respiratory pathogens.

Objective To explore the feasibility of detecting iduronate 2-sulfatase (IDS) activity in dried blood spot (DBS) for screening of mucopolysaccharidosis type Ⅱ (MPS Ⅱ) in newborns. Methods The IDS activity of DBS was detected by fluorescence quantification method, and MPS Ⅱ screening was performed on 2202 male newborns born from February to April 2021 in the Neonatal Disease Screening Center of the hospital. The 51 confirmed children with MPS Ⅱ, 15 female carriers of MPS Ⅱ and 32 non-MPS Ⅱ children (the control group, all male) collected by the Department of Pediatric Endocrinology and Genetic Metabolism from March 2012 to December 2020 were taken as the pre-screened population. A preliminary screening cut-off value for positive cases has been established, and those who test positive will be recalled for retesting of enzyme activity and urine mucopolysaccharides and IDS gene testing. Results The median age of 51 children with MPS Ⅱ was 4.2 years, the median age of 15 female carriers with MPS Ⅱ was 27.5 years, and the median age of 32 control patients was 4.5 years. ROC curve was drawn, and the optimal threshold of DBS for detection of blood IDS activity was 9.59 ρmol/(punch‧20h) in 98 pre-screened patients, with sensitivity of 100%, specificity of 22.7% and AUC of 0.962 (0.928-0.995). The consistency analysis between the white blood cell method and DBS method showed that Kappa=0.96 (P<0.001). The activity level of IDS in 2202 neonates was detected by DBS method. The median value of IDS activity was 58.22 ρmol/(punch‧20h) and 20% of the median value was 11.64 ρmol/(punch‧20h). Whether the DBS IDS activity ≤9.59 ρmol/(punch‧20h) or≤11.64 ρmol/(punch‧20h) was taken as the positive cut-off value, 6 cases (0.27%) were detected as positive and recalled. Among the initial screening positive cases, although 3 patients had a qualitatively positive urine mucopolysaccharides, the electrophoresis showed only chondroitin sulfate band without dermatan sulfate and heparan sulfate bands. Genetic testing found five cases carrying the mother- derived IDS missense variant of c.851C>T (p.P284L) and one case carrying c.1499C>T (p.T500I), all of which were classified as benign variants. Conclusions The IDS activity test on DBS can effectively and promptly identify suspected patients with MPS Ⅱ and can be used for newborn screening of MPS Ⅱ. However, a large sample size study is still needed to determine the accurate positive cut-off value.

Objective The aim of this study was to explore the clinical and genetic characteristics of 7 pediatric patients with neurodegeneration with brain iron accumulation (NBIA). Methods Genetic mutation analysis was conducted on patients suspected of having NBIA using whole exome sequencing (WES), followed by Sanger sequencing for positive cases. A retrospective analysis of the patients' clinical data was performed alongside a literature review. Results Seven patients, comprising five boys and two girls with an average age of 5.4±3.8 years, presented to the hospital primarily due to motor developmental delay. The main clinical manifestations included intellectual disability, gait disorders, abnormal posture, delayed or regressed psychomotor development, muscle weakness, cerebellar ataxia, and retinitis pigmentosa. WES identified pathogenic mutations in NBIA-related genes in all 7 patients, specifically PANK2 in one case, FA2H in one case, and PLA2G6 in five cases. Patients with PLA2G6 variations exhibited early onset, developmental delay, muscle weakness, low signal iron deposition in the pallidus, and cerebellar atrophy. The patient with a PANK2 gene mutation showed gait and postural abnormalities, while the patient with an FA2H mutation presented with language delay, gait abnormalities, and dysmyotonia. Conclusion There is significant heterogeneity in the clinical phenotype of NBIA patients, with neurological abnormalities being the predominant feature. Two previously unreported variants were identified, broadening the spectrum of genetic variations in NBIA disease.

Objective To determine the trace elements and oxidative/antioxidant factors in cord blood of premature infants, and to clarify their value in predicting the onset and evaluation of neonatal respiratory distress syndrome (NRDS). Methods Premature infants with gestational age less than 34 weeks who were hospitalized in the neonatal department from Dec. 2022 to Dec. 2023 were selected as the subjects. The levels of trace elements were determined by flame atomic absorption spectroscopy, and the levels of oxidative factor malondialdehyde (MDA) and antioxidant factor superoxide dismutase (SOD) were measured by surface linked immunosorbent assay. The differences in the above indicators between the NRDS group and the control group were compared. The value of each indicator in predicting the onset of NRDS were determined by the receiver operative curve (ROC). Results The cord blood copper levels and zinc levels in the NRDS group were significantly lower than those in the control group. The SOD level in the NRDS group was lower than that in the control group, and the MDA level was higher than that in the control group. Meanwhile, the SOD/MDA ratio in the NRDS group was significantly lower than that in the control group. The area under the curve of zinc, copper, SOD, MDA, and SOD/MDA in cord blood predicting the onset of NRDS were 0.728, 0.917, 0.627, 0.780, and 0.824, respectively. Conclusions The decrease in levels of trace elements copper and zinc in cord blood and the imbalance of oxidative/antioxidant factors are involved in the pathogenesis of neonatal respiratory distress syndrome.

Objective To investigate the clinical and genetic characteristics of PRKAG2 cardiac syndrome (PCS) in Chinese pediatric patients. Methods A retrospective analysis was conducted on the clinical data and genetic testing results of patients diagnosed with PCS at Shanghai Children's Medical Center from September 1999 to October 2022. Results Seven pediatric patients were included in this study, six males and one female, with a median age of onset of 9.0 (3.0-12.0) years. Five patients had varying degrees of left ventricular hypertrophy, four had ventricular preexcitation, two had atrioventricular conduction block, and one experienced sinus arrest.Six variants in the PRKAG2 gene were identified among the seven patients, including two novel mutations (F293V, Q337H). During a median follow-up of 3.0 (2.0-3.8)years, one patient progressed to end-stage heart failure and underwent heart transplantation, one received a pacemaker due to complete atrioventricular block, and two underwent septal reduction therapy for left ventricular outflow obstruction (septal myectomy or septal radiofrequency ablation, respectively). Conclusions PCS is a rare cause of hypertrophic cardiomyopathy in children, often associated with conduction system abnormalities. It is crucial to consider screening for PCS in pediatric patients with hypertrophic cardiomyopathy who present with pre-excitation syndrome or bradyarrhythmias.

Objective The pursuit of salvage treatment for refractory macrophage activation syndrome (MAS) associated with systemic juvenile idiopathic arthritis (sJIA) is of paramount importance. This paper aims to investigate the application options and therapeutic efficacy of ruxolitinib in the treatment of refractory sJIA-MAS. Methods A retrospective analysis was performed on the clinical data of a child with refractory sJIA-MAS and the outcome following the administration of ruxolitinib. Results An 11-year-old girl, diagnosed with sJIA for four years and having experienced two previous episodes of MAS, was admitted to the hospital due to active sJIA and developed MAS again during the treatment course. Despite three rounds of high-dose methylprednisolone pulse therapy in combination with cyclosporine A and tocilizumab (TCZ), her condition failed to improve, with persistent high fever and severe liver function impairment, among other abnormal laboratory indicators. After discontinuing TCZ and initiating ruxolitinib with an adjusted oral dose of 10 mg twice daily, the child's condition improved, enabling a smooth reduction of the hormone dosage. Ruxolitinib was discontinued after approximately three months of treatment, and there was no recurrence of the disease. Conclusion Ruxolitinib may potentially serve as a salvage treatment option for refractory sJIA-MAS.

Catecholaminergic polymorphic ventricular tachycardia is a hereditary cardiac channelopathy. Most cases are related to mutations in the RYR2 and CASQ2 genes, which severely disrupt the calcium homeostasis in cardiac cells. Excessive calcium release leads to delayed depolarization, ultimately leading to arrhythmia. This disease is seen in patients who experience syncope after intense exercise or stress-related emotions, as well as in patients with sudden cardiac arrest or even sudden cardiac death. It is mainly diagnosed through exercise stress testing and genetic testing. Standard treatment for CPVT relies on beta-blockers, while flucainide and left ventricular sympathetic nerve denervation are second-line treatments. Implantation of cardioverter defibrillators is suitable for patients at a high risk of sudden death, and some potential therapeutic interventions have also been identified. This review summarizes the genetics, pathophysiology, clinical features, diagnosis, and treatment strategies of CPVT, with the aim of providing clinical guidance.

Pediatric inflammatory bowel disease (IBD) is a chronic, recurrent inflammatory condition of the intestines with unknown etiology and complex pathogenesis, posing significant challenges in diagnosis and treatment. IBD severely impacts the growth and development of affected children, diminishes their quality of life, and may negatively influence their psychological and social behavior, imposing a substantial economic burden on society. In recent years, the incidence of pediatric IBD in China has been on the rise, drawing significant attention from pediatricians. Establishing a new model of precision therapy for pediatric IBD has become a goal for pediatricians and scholars worldwide. Precision medicine has proven effective in early screening and diagnosis of cancers and neonatal genetic diseases, providing new methods and perspectives for the treatment of pediatric IBD. This paper reviews the current application of precision therapy in pediatric IBD, elucidating its role in the treatment of pediatric IBD.

Spinal muscular atrophy (SMA) is a rare autosomal recessive disease of progressive, symmetrical proximal limb and trunk muscle weakness and atrophy caused by degeneration of motor neurons in the anterior horn of the spinal cord. SMA patients are often accompanied by scoliosis, joint contracture, respiratory insufficiency, osteoporosis, restricted mouth opening, malnutrition and other damage symptoms involving multiple systems, and the treatment of the disease requires multidisciplinary intervention. Multidisciplinary diagnosis and treatment of SMA can effectively shorten the diagnostic time, improve the life quality of patients. This study, through a literature review, sorts out the development of multi-disciplinary diagnosis and treatment of SMA in disease diagnosis and treatment, and the implementation of three-level prevention and control at home and abroad in recent years, providing research basis for the future improvement of multi-disciplinary diagnosis and treatment of SMA.

Due to the age characteristics of children, esophageal damage caused by accidental ingestion of corrosive substances has become a common accidental injury for children. The acute injury and long-term sequelae resulting from esophageal corrosive injury have become the key and difficult points in the treatment of esophageal corrosive injury in children. This paper reviews the occurrence mechanism and the latest treatment schemes of esophageal corrosive injury, emphasizing the significance of correctly choosing emergency treatment measures and treatment plans for long-term sequelae, with the aim of reducing the occurrence of complications. It has practical guiding significance for the diagnosis and treatment of esophageal corrosive injury in children.