Objective:To investigate the epidemiological and clinical characteristics of human parainfluenza viruses (HPIVs) infection among hospitalized children with community-acquired pneumonia (CAP) in China, and provide basic data for diagnosis, treatment and prevention of HPIVs infection.Methods:From November 2014 to February 2020, 5 448 hospitalized children with CAP were enrolled in 14 hospitals in 11 provinces and municipalities directly under the Central Government in southern China and northern China. Nasopharyngeal aspirates or throat swabs were collected, and the nucleic acids of 18 types respiratory viruses including HPIV1-4 were screened by suspension array technology. Demographic data and clinical information were collected for statistical analysis.Results:The total detection rate of HPIVs in 5 448 children with CAP was 8.83% (481/5 448), and the detection rate in males was higher than that in females (62.79% vs. 37.21%; χ2=0.000, P=0.992). The detection rate of HPIVs in 1~< 3 years age group was higher than that in other age groups, and the difference was statistically significant ( χ2=61.893, P<0.001). The detection rate of HPIVs in the northern region was higher than that in the southern region (9.02% vs 8.65%), but the difference was not statistically significant ( χ2=0.239, P=0.625). The prevalence of HPIV1-4 in northern and southern China was not completely same. HPIV1 was mainly prevalent in autumn in both northern and southern regions. HPIV2 was prevalent in summer in northern China, and the detection rate was low in southern China. HPIV3 reached its peak in both spring and summer in both northern and southern China, but its duration was longer in southern China than in northern China. HPIV4 is mainly popular in autumn in both southern China and northern China. Among 481 children infected with HPIVs, 58.42% (281/481) were infected with HPIV alone, and the main clinical manifestations were cough (90.75%) and fever (68.68%). Out of the HPIV-positive cases, 42.62% (205/481) were co-infected with another type of HPIV or a different virus, while 11.43% (55/481) had co-infections with two or more different viruses. HPIV3 was the most common type of co-infection with other viruses. HPIV3 infection accounted for the largest proportion (76.80%) in 47 HPIVs-positive children with severe pneumonia. Conclusions:HPIVs is one of the most important pathogens causing CAP in children in China, and children under 3 years of age are the main populations of HPIVs infection. The prevalence characteristics of all types of HPIVs in children in the north and south are not completely same. HPIV3 is the dominant type of HPIV infections and causes more severe diseases.

Allergen immunotherapy(AIT)is considered the treatment capable of modifying the natural history of allergic respiratory disorders.The adverse reactions associated with AIT limit its clinical use in moderate to severe allergic asthma.Omalizumab is currently approved for the treatment of allergic asthma, chronic spontaneous urticaria, allergic rhinitis and other allergic diseases.A few trials have demonstrated the clinical efficacy of AIT and omalizumab combination therapy in children with moderate to severe allergic asthma.This review summarizes the research progress, mechanisma and application of omalizumab combined with AIT in children with moderate to severe allergic asthma.

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

China has classified the Corona Virus Disease 2019(COVID-19) as a statutory category B infectious disease and managed it according to Category B since January 8, 2023.In view that Omicron variant is currently the main epidemic strain in China, in order to guide the treatment of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in children with the times, refer to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial 10 th Edition), Expert Consensus on Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fourth Edition) and the Diagnosis and Treatment Strategy for Pediatric Related Viral Infections.The Expert Consensus on the Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fifth Edition) has been formulated and updated accordingly on related etiology, epidemiology, pathogenic mechanism, clinical manifestations, auxiliary examination, diagnosis and treatment, and added key points for the treatment of COVID-19 related encephalopathy, fulminating myocarditis and other serious complications for clinical reference.

H 1-antihistamines are widely used in the treatment of various allergic diseases, but there are still many challenges in the safe and rational use of H 1-antihistamines in pediatrics, and there is a lack of guidance on the prescription review of H 1-antihistamines for children.In this paper, suggestions are put forward from the indications, dosage, route of administration, pathophysiological characteristics of children with individual difference and drug interactions, so as to provide reference for clinicians and pharmacists.

Airway epithelial damage, increased Th2 inflammatory response, and impaired immune regulatory T cell function are important mechanisms for the development of asthma.Indoleamine 2, 3-dioxygenase(IDO) is induced by LPS and IFN-γ, which regulates the differentiation of naive T cells into CD4 + CD25 + regulatory T cells(Treg)and induces immune tolerance.It can inhibit eosinophilic airway inflammation.Decreased IDO activity may promote the development of asthma.Tryptophan metabolites act on AhR receptors to promote the production of IL-22 and enhance the integrity of the epithelium and its resistance to infection.The Th17/Treg balance induced by specific immunotherapy could be altered, and Treg cell proliferation was observed.Tryptophan metabolites can reduce airway inflammation and inflammatory cytokine infiltration.D-tryptophan can promote the diversity of intestinal flora, increase the number of Treg in lung and colon, reduce Th2 reaction, and reduce airway hyperresponsiveness.Tryptophan and its metabolites, IDO and D-tryptophan play an important role in the occurrence, development and specific immunotherapy of asthma.

Thymic stromal lymphopoietin(TSLP)can enhance the secretion of type 2 cytokines by type 2 T helper(Th2)cells and type 2 innate iymphocytes(ILC2s)in the lung through direct and indirect action.In terms of indirect effects, TSLP can promote the proliferation and expansion of naive CD4 + T cells by using dendritic cells, and promote the recruitment of Th2 cells to the initial inflammatory site.It can also use stromal mononuclear/macrophages cells to start the acute primary Th2-dependent immune response.In the aspect of direct effect, TSLP can activate ILC2s before the adaptive immune response is initiated, and also can use immature T cells, effector Th2 cells and memory Th2 cells to participate in the adaptive immune response.Therefore, TSLP plays an important role in allergic immune response of lung.

Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.

Objective:To explore the value of early pulmonary function tests in children with community acquired pneumonia(CAP)by analyzing the clinical and imaging manifestations and pulmonary function tests of children with CAP.Methods:The clinical data of children diagnosed with CAP and undergoing routine pulmonary ventilation tests within 24 hours of admission were retrospectively collected from January 2016 to June 2018 in the Department of Pediatric Respiratory Medicine of Shengjing Hospital Affiliated to China Medical University.The children′s pulmonary ventilation function test data were statistically analyzed with clinical manifestations, laboratory tests and imaging data.Results:A total of 154 children were included in the study, of which 54(35.06%)had normal pulmonary ventilation function, and the remaining 100 children(64.94%)had different degrees of pulmonary ventilation impairment, which were manifested as restrictive ventilation disorder in 54 cases(35.06%), obstructive ventilation disorder in 8 cases(5.19%), mixed ventilation disorder in 30 cases(19.48%), and small airway ventilation dysfunction in 8 cases(5.19%). According to the results of pulmonary ventilation function, the mixed ventilation dysfunction group had a greater probability of pulmonary imaging changes to consolidation than the normal group( χ2=7.83, P=0.007). Mycoplasma pneumoniae infection was negatively correlated with forced expiratory volume in the first second, 75% forced expiratory flow, one second rate and maximal mid-expiratory flow level( r=-0.23, r=-0.22, r=-0.25, r=-0.23, all P<0.05), and there was no significant correlation with the level of forced vital capacity. Conclusion:Early pulmonary ventilation test has important clinical significance in the diagnosis and treatment of CAP in children.

In the state of disease, the mucin composition and fluid secretion of respiratory mucus change significantly, which changes the physical and chemical properties of mucus, so as to promote the progress of the disease.Respiratory mucus has different characteristics in different diseases, which is reflected in the formation mechanism, components, functions and so on.This paper mainly expounds the different characteristics of children′s respiratory mucus(especially mucus plug)in bronchial asthma, lower respiratory tract infection, cystic fibrosis and idiopathic pulmonary fibrosis.