[Epidemiological characteristics of human respiratory syncytial virus among acute respiratory infection cases in 16 provinces of China from 2009 to 2023].

Objective: To understand the epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023. Methods: The data of this study were collected from the ARI surveillance data from 16 provinces in China from 2009 to 2023, with a total of 28 278 ARI cases included in the study. The clinical specimens from ARI cases were screened for HRSV nucleic acid from 2009 to 2023, and differences in virus detection rates among cases of different age groups, regions, and months were analyzed. Results: A total of 28 278 ARI cases were enrolled from January 2009 to September 2023. The age of the cases ranged from<1 month to 112 years, and the age M (Q1, Q3) was 3 years (1 year, 9 years). Among them, 3 062 cases were positive for HRSV nucleic acid, with a total detection rate of 10.83%. From 2009 to 2019, the detection rate of HRSV was 9.33%, and the virus was mainly prevalent in winter and spring. During the Corona Virus Disease 2019 (COVID-19) pandemic, the detection rate of HRSV fluctuated between 6.32% and 18.67%. There was no traditional winter epidemic peak of HRSV from the end of 2022 to the beginning of 2023, and an anti-seasonal epidemic of HRSV occurred from April to May 2023. About 87.95% (2 693/3 062) of positive cases were children under 5 years old, and the difference in the detection rate of HRSV among different age groups was statistically significant (P<0.001), showing a decreasing trend of HRSV detection rate with the increase of age (P<0.001). Among them, the HRSV detection rate (25.69%) was highest in children under 6 months. Compared with 2009-2019, the ranking of HRSV detection rates in different age groups changed from high to low between 2020 and 2023, with the age M (Q1, Q3) of HRSV positive cases increasing from 1 year (6 months, 3 years) to 2 years (11 months, 3 years). Conclusion: Through 15 years of continuous HRSV surveillance analysis, children under 5 years old, especially infants under 6 months old, are the main high-risk population for HRSV infection. During the COVID-19 pandemic, the prevalence and patterns of HRSV in China have changed.

[Analysis of echocardiographic features and postnatal management of fetal pulmonary valve stenosis].

Objective: To investigate the echocardiographic features, consistency of diagnosis between fetal and postnatal periods and postnatal clinical outcomes of fetal pulmonary valve stenosis (PS) with different degrees. Methods: This study was a retrospective cohort study comprising 108 cases of fetal PS diagnosed during the fetal period and followed up postnatally at Xinhua Hospital, Shanghai Jiaotong University School of Medicine from November 2012 to February 2023. Echocardiographic characteristics, including morphological and hemodynamic features were collected for all fetuses who were then were followed up to at least 6 months after birth. One-way analysis of variance and Kruskal-Wallis test were used to compare the differences in the echocardiographic features among fetuses with different degrees of PS. Subsequently, McNemar test was used to assess the consistency of diagnosis between the fetal and postnatal periods. Furthermore, Logistic regression analysis was applied to explore the risk factors for neonatal intervention in fetuses with moderate PS and the receiver operating characteristic (ROC) curve was utilized to ascertain the optimal cut-off value for continuous variables. Results: The age of the mothers of the 108 fetuses at the initial assessment was (30.8±4.0) years, and the gestational age was 26.5 (24.6, 30.0) weeks. The fetuses were categorized into mild (17 cases), moderate (49 cases), and severe groups (42 cases) based on the initial echocardiographic features. Mild PS was characterized by valve thickening and hyperechogenicity combined with systolic flow acceleration or dilation of main pulmonary artery. Moderate PS exhibited both restricted valve motion and a colorful blood flow pattern at the valve orifice. The peak flow velocities of fetuses with moderate and critical PS were notably higher than those in the mild group ((2.66±0.86) and (2.77±1.30) vs. (1.43±0.59)m/s, F=14.52, P<0.001). In critical PS, all cases showed retrograde ductal flow, with a significantly higher proportion of a small right ventricle compared to the mild and moderate PS (42.9% (18/42) vs. 0 and 2.0% (1/49), χ2=31.73, P<0.001). The proportion of severe tricuspid regurgitation was also higher (35.7% (15/42) vs. 0 and 10.2% (5/49), χ2=36.94, P<0.001). Compared to mild and severe PS, the consistency of diagnosis between fetal and postnatal periods in moderate PS was lower (40.8% (20/49) vs.13/17 and 80.3% (35/42), χ2=12.45, P=0.006). The systolic flow velocity was identified as an independent risk factor for neonatal intervention in fetuses with moderate PS (OR=7.21, 95%CI2.11-24.62). A flow velocity of ≥2.18 m/s in second trimester and ≥3.15 m/s in third trimester indicated the necessity of neonatal intervention for fetal moderate PS. Among the 108 fetuses, 68 underwent surgical intervention and all survived. Additionally, 39 fetuses were regularly followed up. A sole non-surgical fatality occurred, leading to a 6-month survival rate of 99.1% (107/108). Conclusions: Various degrees of fetal PS demonstrate distinctive morphological and hemodynamic alterations in echocardiography. The disparity in severity between the postnatal and fetal stages requires ongoing monitoring for fetal PS. The prognosis for fetal PS is generally favorable.

[Pathogenic agents causing acute respiratory tract infections in pediatric patients in Spring, 2023, in Beijing].

Objective: To explore the pathogenic agents of acute respiratory infection (ARI) in children in Beijing. Methods: In the cross-sectional study, 3 groups of children from different departments were enrolled from Feb 6th, 2023 (6th week) to May 28th (21th week), 2023, including influenza-like case group from emergency department for nucleic acid testing of influenza virus (Flu) and human metapneumovirus (HMPV), the outpatient ARI group under nucleic acid testing for Flu, respiratory syncytial virus (RSV), adenovirus (ADV), and parainfluenza virus (PIV), and the inpatient ARI group under nucleic acid testing for Flu, RSV, HMPV, ADV, human bocavirus (HBoV), Rhinovirus (Rh), PIV, coronavirus (HCoV), Mycoplasma pneumoniae (Mp) and Chlamydia pneumonia (Cp). Results: There were 320 influenza-like cases enrolled, including 192 males and 128 females, aged 4.7 (3.6, 6.9) years, and 117 cases (36.6%) positive for Flu A, which contained similar proportion of pandemic H1N1 (H1N1) 47.0% (55/117) and H3N2 53.0% (62/117), and 13 cases for HMPV 4.1% (13/320). The rate of Flu reached its peak at the 10th week, with H1N1 as the predominant one from the 6th to 9th week (10.0%-50.0%) and then H3N2 from the 10th to 16th week (15.0%-90.0%). HMPV was detected from the 15th week 5.0% (1/20), and then reached to 30.0% (6/20) at the 20th week. In the outpatient ARI group, 7 573 were enrolled, including 4 131 males and 3 442 females, aged 4.0 (2.1, 5.3) years, and the highest positive rate for RSV 32.9% (2 491/7 573), followed by Flu A 12.1% (915/7 573). The dominant one was Flu A in weeks 6-14 (23.2%-74.7%), then RSV in the 15th week 24.8% (36/145). In the inpatient ARI group, 1 391 patients were enrolled, including 804 males and 587 females, aged 3.3 (0.4, 5.8) years, and the highest positive rate for Rh 18.7% (260/1 391), followed by RSV 12.4% (173/1 391), Flu A 10.2% (142/1 391, of which 116 cases (81.7%) were H1N1, and 26 cases (18.3%) were H3N2) and HMPV 3.1% (43/1 391). H1N1 was detected from the 7th week 10% (6/60), to peak in the 11th week 31.8% (21/66). H3N2 was detected from the 8th week 1.5% (1/68), and then kept in low level. The proportion of H1N1 among Flu was 81.7% (116/142) in the inpatient ARI group. RSV was detected from 12th week 1.3% (1/80), reaching 30.4% (35/115) at 19th week. The positive rate of HMPV reached 12.1% (14/116) at 21th week. Conclusions: In the spring of 2023, the first one in Beijing is the Flu epidemic, with H1N1 being the predominant one in the early stage and H3N2 in the later stage. Then, there is a postponed RSV epidemic and an increased HMPV detection. In addition, nucleic acid testing for outpatient children should be strengthened to provide early warning of epidemics.

[Clinical characteristics analysis of 4 cases with acute flaccid myelitis in children].

Objective: To summarize the clinical manifestations, diagnosis, treatment and prognosis of acute flaccid myelitis (AFM) in children. Methods: Clinical characteristics of 4 AFM cases from Department of Neurology, Children's Hospital Affiliated to Capital Institute of Pediatrics, from September 2018 to November 2022, were analyzed retrospectively. Results: The age of 4 children with AFM was 7 years, 4 years and 3 months, 7 years and 1 month, 6 years and 5 months, respectively. There were 2 boys and 2 girls. Prodromal infection status showed 3 children of respiratory tract infection and 1 child of digestive tract infection. The main manifestation was asymmetrical limb weakness after infection, and the affected limb range was from monoplegia to quadriplegia. Cranial nerve injury was involved in 1 child, no encephalopathy. Magnetic resonance imaging in the spinal cord of all 4 children showed long T1 and T2 signals, mainly involving gray matter. Cerebrospinal fluid cell-protein separation was observed in 2 children. Pathogen detected in 1 child pharyngeal swab was enterovirus D68. Antibody IgM to adenovirus was positive in the blood of 1 child. Antibody IgG against Echo and Coxsackie B virus were positive in the blood of another child. After glucocorticoid, human immunoglobulin or simple symptomatic treatment and at the same time under later rehabilitation training, muscle strength recovered to different degrees, but there were disabilities left in 3 children. Conclusions: AFM should be considered in children with acute and asymmetrical flaccid paralysis accompanied by abnormal magnetic resonance imaging signal in the central region of spinal cord, especially post-infection. The effective treatment is limited and the prognosis is poor.