Sepsis, whose morbidity and mortality remain high in children, is a life-threatening organ dysfunction resulting from dysregulated host responses to infection.With the global outbreak of Corona Virus Disease 2019, viral sepsis, especially respiratory viral sepsis, has attracted much attention.Early diagnosis and timely intervention are of great benefit to improve the prognosis of patients.This review focuses on the epidemiology, pathophysiology, diagnosis, and treatment of respiratory viral sepsis in children to provide clinical reference.

Objective:To compare the clinical characteristics and etiology changes of patients with bronchiolitis before the pandemic of coronavirus disease 2019(COVID-19)with those after the pandemic, and to provide a basis for the clinical diagnosis, treatment and prevention of bronchiolitis.Methods:Retrospective analysis were made on the clinical characteristics and etiological changes of patients who were hospitalized with bronchiolitis in the Department of Pulmonology, Children′s Hospital of Soochow University before COVID-19 pandemic(from February 1, 2019 to January 31, 2020, called as Group 2019-2020)and after COVID-19 pandemic(from February 1, 2020 to January 31, 2021, called as Group 2020-2021). Medical records were reviewed to compare general conditions, clinical manifestations, and laboratory tests.Nasopharyngeal secretion examination results were collected to compare the differences in pathogenic composition.Results:A total of 285 patients were enrolled in the Group 2019-2020, while 190 patients in the Group 2020-2021.There were no significant differences in gender, age, symptom duration prior to admission and length of stay between the two groups( P>0.05). The proportion of moderate/severe cases in the Group 2020-2021 was lower than that in the Group 2019-2020[10.53%(20/190)vs 21.75%(62/285)]and the difference was statistically significant( χ2=10.062, P<0.05). The proportion of stuffy nose rhinorrhea in the Group 2020-2021 was higher than that in the Group 2019-2020, while the proportion of gastrointestinal symptoms(vomiting and diarrhea)in the Group 2020-2021 was lower than that in the Group 2019-2020 [57.37%(109/190)vs 47.37%(135/285)and 15.79%(30/190)vs 24.56 %(70/285)]and the differences were statistically significant( χ2 were 4.563 and 5.278 respectively, all P<0.05). There were no significant differences in the proportions of fever, dyspnea, shortness of breath and cyanosis between the two groups(all P>0.05). The creatine kinase isoenzyme(CK-MB)in the Group 2020-2021 was lower than that in the Group 2019-2020[4.15(2.90~5.60)vs 6.70(4.20~22.10)]and the difference was statistically significant( Z=-8.757, P<0.05). There were no statistically significant differences in white blood cell count(WBC), percentage of neutrophil(N%), blood platelet count(PLT), percentage of eosinophil(EOS%), C-reactive protein(CRP), alanine aminotransferase(ALT)and lactate dehydrogenase(LDH)between the two groups(all P>0.05). The total pathogen detection rate, positive rate of respiratory syncytial virus(RSV), positive rate of mycoplasma pneumoniae(MP)and mixed infection rate in the Group 2020-2021 were lower than those in the Group 2019-2020[65.26%(124/190)vs 75.09%(214/285), 14.21%(27/190)vs 30.18%(86/285), 6.32%(12/190)vs 15.09%(43/285), 16.84%(32/190)vs 25.61%(73/285)], with statistically significant differences( χ2 were 5.361, 16.026, 8.568 and 5.094 respectively, all P<0.05). The positive rate of rhinovirus in the Group 2020-2021 was higher than that in the Group 2019-2020[13.16%(25/190)vs 4.91%(14/285)]and the difference was statistically significant( χ2=10.285, P<0.05). There were no significant differences in the positive rates of human metapneumovirus, Boca virus and parainfluenza virus 3 between the two groups(all P>0.05). Conclusion:The clinical characteristics and etiology of patients with bronchiolitis have changed after the COVID-19 pandemic.The quarantine and protection measures reduce the transmission of associated pathogens and the severity of the disease.

Objective:To investigate the detection, epidemiological and clinical characteristics of human rhinovirus(HRV) in hospitalized children with respiratory tract infections.Methods:The study population comprised of 10 514 children with respiratory tract infections admitted to Department of Respiration, the Children′s Hospital of Soochow University, between January 2013 and December 2019.The nasopharyngeal aspirates and medical history were obtained by qualified medical personnel.Reverse transcription-polymerase chain reaction method was used to test HRV.Results:The total positive rate of human rhinovirus was 14.2%(1 493/10 514), and there was no significant difference between male and female( χ2=2.006, P=0.157). The positive rates from 2013 to 2019 were 9.7%, 14.6%, 19.1%, 18.6%, 18.1%, 11.0%, 11.4% respectively, and there were significant differences among these groups( χ2=116.580, P<0.001). HRV distributed throughout the year with a peak in summer and autumn(June to November), followed by spring, and the lowest in winter.The detection rates of HRV infection rates were 14.2%, 15.5%, 13.5% and 9.8% in the age group of 28 d~6 months, ~2 years, ~7 years and>7 years respectively, and there were significant differences among these age groups( χ2=16.124, P<0.001). The detection rate of HRV in children under 2 years was higher( χ2=7.711, P=0.005). The clinical characteristics of HRV infection were fever, cough, wheezing and even dyspnea.Bronchopneumonia had the highest percentage(68.9%), followed by bronchitis(13.2%). Compared with non-coinfection group, patients with coinfection with other viruses were more prone to wheezing and pulmonary rales( χ2=9.483, 10.821, P=0.024, 0.013), and coinfection with mycoplasma was more likely to cause fever and lobar pneumonia( χ2=51.585、96.060, P all<0.001); 57.8% presented leukocytosis, while 15.6% showed a higher CRP(>15 mg/ml). The increase of CRP and leukocytosis were more obvious in children under 2 years of age( χ2=26.097, 55.973, P all<0.001). Conclusion:HRV was a major viral pathogen of RTIs in recent 7 years, distributing throughout the year with a peak in summer and autumn, mainly involving children under 2 years of age.The clinical features were diverse, and the clinical symptoms were severe in childhood coinfections with other pathogens.

Objective:To investigate the clinical characteristics of influenza A and influenza B pneumonia and the risk factors of severe influenza pneumonia in children.Methods:The epidemiology, clinical characteristics, laboratory tests and pathogens of co-infection in children with pneumonia caused by influenza A virus and influenza B virus, and the risk factors of severe influenza pneumonia were retrospectively analyzed.Results:(1) The cases of influenza A infection accounted for 65.1% and those with influenza B infection accounted for 32.9% among the 711 children with influenza pneumonia.The dominant strain was Influenza B Victoria virus in spring and summer, influenza A(H 3N 2) virus in autumn, and influenza A(H1N1) virus in winter.The dominant strain was influenza A virus at the age of < 1 year and ~3 years, influenza A virus and influenza B virus at the age of ~6 years, and influenza B virus at the age of ≥6 years.(2) The gastrointestinal symptoms were more common in children with influenza B pneumonia compared with those with influenza A pneumonia(53.4% vs 44.7%, χ2=4.728, P=0.030), but crackles and wheezing were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(80.1% vs 70.5%, 36.9% vs 25.6%, χ2=8.945, 8.093, all P<0.05). (3) The percentage of decreased lymphocyte count in children with influenza B pneumonia was higher than those with influenza A pneumonia(5.6% vs 1.9%, χ2=6.633, P=0.010). (4) Mixed Mycoplasma Pneumoniae was more common in children with influenza B pneumonia compared with those with influenza A pneumonia(23.9% vs 10.8%, χ2=20.789, P<0.001), and mixed virus and bacteria were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(15.8% vs 8.1%, 50.1% vs 41.9%, χ2=7.934, 4.221, all P<0.05). (5) Multivariate logistic regression analysis showed that age <2 years( OR=1.886, 95% CI 1.149~3.096, P=0.012), increased LDH( OR=1.736, 95% CI 1.080~2.790, P=0.023), the percentage of lymphocyte decreased( OR=2.762, 95% CI 1.669~4.571, P<0.001) and the percentage of CD3 + decreased ( OR=6.019, 95% CI 3.993~9.331, P<0.001)were risk factors for severe influenza pneumonia. Conclusion:Among hospitalized children with influenza pneumonia, there were some differences in the age of infection, clinical characteristics, laboratory tests and pathogens of co-infection between the cases caused by influenza B and influenza A, and clinicians should remain vigilant for the occurrence of severe influenza pneumonia.

Objective:To explore the clinical features and risk factors of systemic lupus erythematosus(SLE) concomitant with interstitial lung disease(ILD) in children.Methods:A retrospective analysis was performed.A total of 111 hospitalized children diagnosed with SLE in the Department of Rheumatology and Immunology, Children′s Hospital of Soochow University from February 2016 to November 2018 were selected as the research subjects and divided into the SLE-ILD group(18 cases) and the SLE-non-ILD group(93 cases)according to the lung high-resolution CT manifestations. T-test and Wilcoxon rank sum test were used to compare and analyze the general situation, clinical manifestations and laboratory results.Multivariate Logistic regression was used to analyze the risk factors of SLE-ILD. Results:The prevalence of SLE-ILD was 16.2%(18/111 cases). There were significant differences between the SLE-ILD group and the SLE-non-ILD group in the course of disease [14.00 (12.00-24.25) months vs.1.00(1.00-2.00) months], the incidence of serositis [55.6%(10/18 cases) vs.8.6%(8/93 cases)], post-activity shortness of breath [83.3%(15/18 cases) vs.25.8%(24/93 cases)], nervous system damage [27.8%(5/18 cases) vs.6.5%(6/93 cases)], cardiovascular system damage [38.9%(7/18 cases) vs.9.7%(9/93 cases)], the occu-rrence of increased erythrocyte sedimentation rate [66.7%(12/18 cases) vs.31.2%(29/93 cases)], the decreased C 3[88.9%(16/18 cases) vs.62.4%(58/93 cases)], positive anti neutrophil cytoplasmic antibody (ANCA) [88.9%(16/18 cases) vs.18.3%(17/93 cases)], positive anti-Sm antibody [61.1%(11/18 cases) vs.15.1%(14/93 cases)] and anti ribonucleoprotein antibody (anti RNP antibody)[66.7%(12/18 cases) vs.16.1%(15/93 cases)](all P<0.05). Logistic regression analysis demonstrated that serositis( OR=30.535, 95% CI: 2.167-430.336, P=0.011), shortness of breath after exercise( OR=55.115, 95% CI: 1.117-2 579.852, P=0.041), positive ANCA( OR=65.090, 95% CI: 4.488-944.071, P=0.002) and positive anti-RNP antibody( OR=10.007, 95% CI: 1.362-73.500, P=0.024) were risk factors for SLE-ILD. Conclusions:The longer the course of SLE, the higher the incidence of ILD; serositis, shortness of breath after exercise, positive ANCA and positive anti RNP antibody may be risk factors for SLE-ILD.

As the second generation macrolide antibiotic, except for antibacterial effects, azithromycin can down-regulate inflammatory responses, reduce mucus secretion and inhibit bacterial biofilms.In addition to the infectious diseases caused by atypical pathogens, viral or bacterial, chronic diseases including cystic fibrosis, chronic rhinosinusitis, asthma, gastroparesis and otherdiseases can be treated with azithromycin.Clinicians should pay more attention to drug resistance and adverse reactions in infant.The article will review the progress of clinical application of azithromycin in recent years and the strategies for drug resistance and adverse effects.

Objective:To explore the epidemiological characteristics and the antibiotic resistance of Streptococcus pneumoniae isolates, and to provide the evidence for the rational use of antimicrobial agents to treat Streptococcus pneumoniae infection. Methods:The positive microbiological laboratory identification and antimicrobial susceptibility testing of Streptococcus pneumoniae from sputum of children with respiratory infections during January 2010 to December 2017 in Children′s Hospital of Soochow University were retrospectively analyzed. The positive rates of Streptococcus pneumoniae of different genders, ages, years and seasons were compared. The annual detection rates and trends of drug resistance of Streptococcus pneumoniae to penicillin, amoxicillin and cefotaxime were analyzed by Mann-Kendall trend test. The seasonal decomposition of time series was conducted to assess the association between Streptococcus pneumoniae detection rate and season. Enumeration data was compared using χ2 test. Results:Of the 88 480 sputum specimens, the total positive rate of Streptococcus pneumoniae was 10.3%(9 081/88 480). The detection rates of Streptococcus pneumoniae in children aged 0 to <0.5 years old, 0.5 to <2 years old, 2 to <3 years old, 3 to <5 years old, and 5 to <15 years old were 4.2%(1 407/33 224), 13.1%(3 191/24 390), 14.9%(2 417/16 252), 17.9%(1 474/8 246) and 9.3%(592/6 368), respectively. The difference was statistically significant ( χ2=2 421.6, P<0.01). The detection rates were 8.1%(1 321/16 306) from January to March, 10.9%(2 194/20 207) from April to June, 8.5%(2 141/25 058) from July to September, and 12.7%(3 425/26 909) from October to December. The discrepancy of positive rates in different seasons showed statistical significance ( χ2=311.5, P<0.01). During 2010 to 2017, significant decreases in antibiotic resistant rates of Streptococcus pneumoniae to penicillin, amoxicillin and cefotaxime were detected (tau=-0.93, -0.93 and -0.71, respectively, all P<0.05). Conclusions:The detection rate of Streptococcus pneumoniae in sputum of children with respiratory infections may present seasonal pattern and vary between different ages of children. The resistance to β-lactam antibiotics has declined.

Necrotizing pneumonia (NP) is a serious complication of community-acquired pneumonia in children.In recent years, with the deepening understanding of pediatricians, reports on NP have increased year by year.The early lesion of NP is characterized by the consolidation of lung tissue.With the progression of the disease, the involved lung tissue appears liquefaction and necrosis, and eventually multiple cysts or cavities are formed.Clinical diagnosis is mainly based on imaging.Previous studies have shown that NP is mostly found in streptococcus pneumoniae and staphylococcus aureus infections.In recent years, mycoplasma pneumoniae has been found to be the main pathogen of necrotizing pneumonia, and adenovirus and influenza virus infections have also been frequently reported.On the basis of reasonable anti-infection treatment, most of the children have a good prognosis by treatement of glucocorticoid, gamma globulin, bronchoscope lavage, closed thoracic drainage, etc.

As a clinical syndrome involving multiple systems, plastic bronchitis(PB)raises a widely interest among researchers due to its complex etiology and unclear pathogenesis.It is currently believed that PB is related to bronchial asthma, cystic fibrosis, sickle cell disease and respiratory tract infection.The main characteristic of PB is the formation of dendritic casts in the bronchus, causing local or extensive obstruction, acute dyspnea, even respiratory failure, and death.Besides, the lack of effective management may result in recurrent respiratory infection, seriously affecting children′s quality of life.The disease is rare in pediatrics, and its clinical and imaging manifestations have no specificity, which can easily lead to misdiagnosis and missed diagnosis.Hence, it is extremely important for early diagnosis and timely removal of plastic substances blocking the airway.

Objective:To analyze the clinical characteristics of patients suffering from plastic bronchitis (PB) caused by Mycoplasma pneumoniae (MP) and explore its risk factors as well. Methods:A retrospective analysis on clinical and laboratory data of PB children caused by MP and treated in Department of Respiratory in Children′s Hospital of Soochow University from January 2011 to December 2017, compared with MP pneumonia(MPP) children without PB in the same period.Meanwhile, Logistic regression analysis was performed. Results:Among the 306 MPP children, there were 50 cases in the PB group and 256 cases in the non-PB group.Compared with children in the non-PB group, children in PB group were higher in terms of age [(82.74±35.17)months vs.(66.63±35.67) months], percentage of neutrophils (0.705 8±0.139 1 vs.0.605 7±0.162 6), C reactive protein(CRP) [17.4(10.21, 42.86) mg/L vs.11.43(4.55, 23.66) mg/L], D-dimer(DD) [1 071 (279.5, 2 386.5) μg/L vs.523 (233, 1 099.5) μg/L], lactate dehydrogenase(LDH) [491.1 (342.3, 607.4) U/L vs.394.9 (319.1, 512.8) U/L], erythrocyte sedimentation rate(ESR)[25.0 (17.0, 36.0) mm/1 h vs.15.5(9.0, 28.0) mm/1 h], aspartate aminotranferase(AST) [33.5(26.1, 49.3) U/L vs.29.2(24.0, 37.2) U/L], alanine aminotransferase (ALT) [19.1(11.45, 31.50) U/L vs.13.6 (10.3, 23.15) U/L], IgA [1.46(0.98, 2.12) mg/L vs.1.15 (0.64, 1.60) mg/L], CD3 -CD (16+56)+ (0.155 0±0.088 6 vs.0.120 2±0.071 5), allergy history [44.0%(22/50 cases) vs.25.8%(65/256 cases)], mixed infection [38.0% (19/50 cases) vs.24.6%(63/256 cases)], and microscopic mucosal erosion [10.0%(5/50 cases) vs.2.3%(6/256 cases)] (all P<0.05). Logistic regression analysis displayed that allergy history ( OR= 5.604, 95% CI: 1.937-16.216), age ( OR = 3.142, 95% CI: 1.425-6.929), percentage of neutrophils ( OR=2.387, 95% CI: 1.088-5.238), CRP ( OR=3.959, 95% CI: 1.072-14.662), and DD ( OR=7.824, 95% CI: 2.824-21.673) were independent risk factors for PB caused by MP infection (all P<0.05). The cut-off values of age, percentage of neutrophils, CRP, and DD were 64 months, 0.70, 35 mg/L, and 2 000 μg/L. Conclusions:Children with PB caused by MP often develop in older and allergic children who have stronger inflammatory reactions, immune disorders, and hyperfibrinolysis.