Objective:To analyze the iodine nutrition status of pregnant women in Weihai City before and after (2022, 2023) the iodine deficiency disorders (IDD) intervention, evaluate the effectiveness of intervention measures, and provide a scientific basis for adjusting IDD prevention strategies in the city.Methods:In May 2023, the intervention action of IDD was carried out for pregnent women in Weihai City. In April 2022 and December 2023, respectively, a cross-sectional survey method was conducted in four districts (cities) of Weihai City. Each district (city) was divided into five areas (east, west, south, north, and central) each year, and one township (street) was selected from each areas. At least 20 pregnant women were selected from each township (street) as survey subjects, and their household salt samples and random urine samples were collected to measure salt iodine and urinary iodine concentrations, and to compare the test results.Results:A total of 922 household salt samples were tested, including 530 iodized salt samples and 469 qualified iodized salt samples. The median salt iodine was 24.00 mg/kg. The coverage rate of iodized salt, the qualified rate of iodized salt, and the consumption rate of qualified iodized salt were 57.48%, 88.49%, and 50.87%, respectively. No significant difference was observed in medians salt iodine between 2022 (24.26 mg/kg) and 2023 (24.00 mg/kg, Z = - 1.58, P = 0.113). However, the coverage rate of iodized salt and the consumption rate of qualified iodized salt in 2023 werehigher than those in 2022 [73.72% (373/506) vs 37.74% (157/416), 65.22% (330/506) vs 33.41% (139/416), χ 2 = 120.90, 92.40, P < 0.001]. A total of 922 urine samples were collected from pregnant women, with a median urinary iodine of 135.90 μg/L. The median urinary iodine of pregnant women in 2022 was 113.55 μg/L. There was a statistically significant difference in medians urinary iodine among different regions ( H = 27.91, P < 0.001). The median urinary iodine of pregnant women in 2023 was 153.00 μg/L. There was no statistically significant difference in medians urinary iodine among different regions ( H = 3.33, P = 0.343). The medians urinary iodine of pregnant women in Huancui District, Wendeng District, and Rushan City in 2023 (156.60, 155.00, 140.85 μg/L) were higher than those in 2022 (93.60, 110.00, 110.70 μg/L), and the differences were statistically significant ( Z = - 5.44, - 4.92, - 5.99, P < 0.001). The median urinary iodine of pregnant women in Weihai City in 2023 showed a statistically significant difference compared to 2022 ( Z = - 7.62, P < 0.001). Conclusions:The IDD intervention measures in Weihai City have achieved good results, and the coverage of iodized salt, the consumption rate of qualified iodized salt, and the iodine nutrition level of pregnant women have improved. We should continue to implement intervention measures, improve the iodine nutrition level of key populations, and maintain a sustained elimination of IDD.

Objective:To explore the molecular epidemiological characteristics of human metapneumovirus (HMPV) in children with acute respiratory infection (ARI) in Beijing from 2023 to 2024.Methods:In the longitudinal study, 9 834 children with ARI were enrolled from August 2023 to December 2024, including the influenza-like illness (ILI) group from emergency and outpatient department receiving influenza virus (Flu) and HMPV test and the ARI inpatient group for 13 common respiratory pathogen screening test including HMPV, Flu, respiratory syncytial virus, and so on. All respiratory samples positive with HMPV were genotyped by amplifying and sequencing of G gene and further phylogenetic analysis. The χ2 test and Wilcoxon rank-sum test were used to compare the positive rate and basic clinical data of the 2 groups. Results:Among 9 834 enrolled patient, there were 5 276 male and 4 558 female children, with age 5.4 (1.9, 8.2) years. In ILI group of 1 460 patients, there were 83 cases (5.7%) positive for HMPV, with the age 4.9 (3.6, 6.6) years and children under 6.0 years old 59 cases (71.1%). Among 8 374 ARI inpatients, there were 256 cases (3.1%) positive for HMPV, with age 3.5 (1.3, 6.4) years and children under 6.0 years old 188 cases (73.4%). The HMPV positive rate and the age of children positive for HMPV in ARI inpatient group were significantly lower than that in ILI group (both P<0.001). In December, 2024, the HMPV positive rates of ILI and ARI inpatient group (21.3% (17/80), 15.0% (47/314)) were significantly higher than the total positive rates of each group (both P<0.001). Among 279 subtyped specimens, there were 155 cases (55.6%) belonging to genotype A and 124 cases (44.4%) belonging to genotype B. Sub-lineage A2.2.2 containing 111nt-insertions was predominate one in 2023 with positive ratio 89.2% (91/102), and B2 was predominate in 2024 with positive ratio 64.4% (114/177). Conclusions:From 2023 to 2024, the positive rate of HMPV in the ILI group was higher than that in the ARI inpatient group, suggesting a common epidemic of HMPV infection. Children positive for HMPV in the ARI inpatient group were younger than that in the ILI group. A severe epidemic of HMPV was observed in the winter of 2024, which requires attention. Sub-lineage A2.2.2 with 111nt-duplicate insertions and B2 were the predominant epidemic strains in 2023 and 2024, respectively.

Objective:To analyze the iodine nutrition status of pregnant women in Weihai City before and after (2022, 2023) the iodine deficiency disorders (IDD) intervention, evaluate the effectiveness of intervention measures, and provide a scientific basis for adjusting IDD prevention strategies in the city.Methods:In May 2023, the intervention action of IDD was carried out for pregnent women in Weihai City. In April 2022 and December 2023, respectively, a cross-sectional survey method was conducted in four districts (cities) of Weihai City. Each district (city) was divided into five areas (east, west, south, north, and central) each year, and one township (street) was selected from each areas. At least 20 pregnant women were selected from each township (street) as survey subjects, and their household salt samples and random urine samples were collected to measure salt iodine and urinary iodine concentrations, and to compare the test results.Results:A total of 922 household salt samples were tested, including 530 iodized salt samples and 469 qualified iodized salt samples. The median salt iodine was 24.00 mg/kg. The coverage rate of iodized salt, the qualified rate of iodized salt, and the consumption rate of qualified iodized salt were 57.48%, 88.49%, and 50.87%, respectively. No significant difference was observed in medians salt iodine between 2022 (24.26 mg/kg) and 2023 (24.00 mg/kg, Z = - 1.58, P = 0.113). However, the coverage rate of iodized salt and the consumption rate of qualified iodized salt in 2023 werehigher than those in 2022 [73.72% (373/506) vs 37.74% (157/416), 65.22% (330/506) vs 33.41% (139/416), χ 2 = 120.90, 92.40, P < 0.001]. A total of 922 urine samples were collected from pregnant women, with a median urinary iodine of 135.90 μg/L. The median urinary iodine of pregnant women in 2022 was 113.55 μg/L. There was a statistically significant difference in medians urinary iodine among different regions ( H = 27.91, P < 0.001). The median urinary iodine of pregnant women in 2023 was 153.00 μg/L. There was no statistically significant difference in medians urinary iodine among different regions ( H = 3.33, P = 0.343). The medians urinary iodine of pregnant women in Huancui District, Wendeng District, and Rushan City in 2023 (156.60, 155.00, 140.85 μg/L) were higher than those in 2022 (93.60, 110.00, 110.70 μg/L), and the differences were statistically significant ( Z = - 5.44, - 4.92, - 5.99, P < 0.001). The median urinary iodine of pregnant women in Weihai City in 2023 showed a statistically significant difference compared to 2022 ( Z = - 7.62, P < 0.001). Conclusions:The IDD intervention measures in Weihai City have achieved good results, and the coverage of iodized salt, the consumption rate of qualified iodized salt, and the iodine nutrition level of pregnant women have improved. We should continue to implement intervention measures, improve the iodine nutrition level of key populations, and maintain a sustained elimination of IDD.

Objective:To explore the molecular epidemiological characteristics of human metapneumovirus (HMPV) in children with acute respiratory infection (ARI) in Beijing from 2023 to 2024.Methods:In the longitudinal study, 9 834 children with ARI were enrolled from August 2023 to December 2024, including the influenza-like illness (ILI) group from emergency and outpatient department receiving influenza virus (Flu) and HMPV test and the ARI inpatient group for 13 common respiratory pathogen screening test including HMPV, Flu, respiratory syncytial virus, and so on. All respiratory samples positive with HMPV were genotyped by amplifying and sequencing of G gene and further phylogenetic analysis. The χ2 test and Wilcoxon rank-sum test were used to compare the positive rate and basic clinical data of the 2 groups. Results:Among 9 834 enrolled patient, there were 5 276 male and 4 558 female children, with age 5.4 (1.9, 8.2) years. In ILI group of 1 460 patients, there were 83 cases (5.7%) positive for HMPV, with the age 4.9 (3.6, 6.6) years and children under 6.0 years old 59 cases (71.1%). Among 8 374 ARI inpatients, there were 256 cases (3.1%) positive for HMPV, with age 3.5 (1.3, 6.4) years and children under 6.0 years old 188 cases (73.4%). The HMPV positive rate and the age of children positive for HMPV in ARI inpatient group were significantly lower than that in ILI group (both P<0.001). In December, 2024, the HMPV positive rates of ILI and ARI inpatient group (21.3% (17/80), 15.0% (47/314)) were significantly higher than the total positive rates of each group (both P<0.001). Among 279 subtyped specimens, there were 155 cases (55.6%) belonging to genotype A and 124 cases (44.4%) belonging to genotype B. Sub-lineage A2.2.2 containing 111nt-insertions was predominate one in 2023 with positive ratio 89.2% (91/102), and B2 was predominate in 2024 with positive ratio 64.4% (114/177). Conclusions:From 2023 to 2024, the positive rate of HMPV in the ILI group was higher than that in the ARI inpatient group, suggesting a common epidemic of HMPV infection. Children positive for HMPV in the ARI inpatient group were younger than that in the ILI group. A severe epidemic of HMPV was observed in the winter of 2024, which requires attention. Sub-lineage A2.2.2 with 111nt-duplicate insertions and B2 were the predominant epidemic strains in 2023 and 2024, respectively.

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.

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.

Objective:To analyze the epidemiological features of respiratory syncytial virus (RSV) infection in Beijing, and monitor the sequence variations in RSV glycoprotein (G) gene and clinical features of infected children.Methods:Respiratory tract specimens were collected from children with acute respiratory infection in the Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 1, 2023 to December 31, 2023. RSV-positive specimens screened by multiple nucleic acid testing were subjected to PCR to amplify the full-length RSV G gene. A phylogenetic tree was constructed after gene sequencing to analyze RSV subtypes and trace G gene variants. Clinical data were retrieved from the medical record system to analyze the clinical features of children with RSV infection in Beijing.Results:A total of 5 489 respiratory specimens were collected from 3 046 male patients and 2 443 female patients. The average age of the patients was 4.36 years. A total of 589 RSV-positive specimens (10.7%, 589/5 489) were detected with 349 from male patients and 240 from female patients. The average age of children with RSV infection was (2.51±2.78) years and the median age was 0.48 years. RSV had been circulating among children in Beijing since March 2023 with two epidemic peaks in May (24.6%, 122/496) and December (18.2%, 126/693). The predominant subtype of RSV in the first half of 2023 was subtype A, but it was replaced by subtype B from November 2023. Phylogenetic analysis revealed a novel G gene of RSV subtype B (RSV-B-BA9-954bp) with a length of 954 bp, which belonged to a new cluster in the phylogenetic tree. The percentage of patients admitted to the Intensive Care Unit (ICU) was higher in children with new variant of RSV subtype B infection than in those with common RSV subtype B infection [44.1% (15/34) vs 25.2% (31/123), χ 2=4.600, P=0.032], while the counts of white blood cells and the levels of C-reactive protein were lower in the children with new variant infection ( P<0.05). Conclusions:RSV has been prevalent among children in Beijing since March 2023 with two epidemic peaks. The predominant A subtype is gradually replaced by to B subtype. A new variant of RSV B G gene (RSV-B-BA9-954bp) is detected among the children.

Objective:To analyze the differentially expressed genes of human respiratory syncytial virus (RSV) subtype A genotype ON1, a predominant genotype in Beijing, after infecting A549 cells using transcriptomic sequencing, and provide potential targets for RSV prevention and treatment.Methods:A local strain (61397-ON1) identified by whole-genome sequencing as ON1 genotype of RSV subtype A was selected to infect A549 cells. Total mRNA was extracted, and the differentially expressed genes in infected and uninfected A549 cells were screened by transcriptomic sequencing. GO analysis and KEGG pathway analysis were performed. Besides, six genes with differential expression ratio greater than two times were randomly selected for qRT-PCR verification.Results:There were 1 632 differentially expressed genes between infected and uninfected A549 cells, of which 807 genes were up-regulated and 825 genes were down-regulated. The differentially expressed genes were mainly involved in immune response-related biological processes such as cytokine response and positive regulation of MAPK cascades, and were enriched in MAPK signaling pathway, NOD-like receptor signaling pathway, p53 signaling pathway, TNF signaling pathway, IL-17 signaling pathway and NF-κB signaling pathway. The results of qRT-PCR for six differentially expressed genes were consistent with the trend of transcriptome data.Conclusions:The differentially expressed genes of RSV A subtype ON1 genotype after infecting A549 cells are mainly involved in cytokine response and immune-related signaling pathways. This study provides basic data for further study of the molecular mechanism of RSV infection and the development of prevention and treatment strategies.

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 6 th, 2023 (6 th week) to May 28 th (21 th 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 10 th week, with H1N1 as the predominant one from the 6 th to 9 th week (10.0%-50.0%) and then H3N2 from the 10 th to 16 th week (15.0%-90.0%). HMPV was detected from the 15 th week 5.0% (1/20), and then reached to 30.0% (6/20) at the 20 th 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 15 th 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 7 th week 10% (6/60), to peak in the 11 th week 31.8% (21/66). H3N2 was detected from the 8 th 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 12 th week 1.3% (1/80), reaching 30.4% (35/115) at 19 th week. The positive rate of HMPV reached 12.1% (14/116) at 21 th 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.

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.