Objective: To analyze the etiological surveillance results of influenza-like illness (ILI) cases in Jiangsu Province, and investigate the distribution characteristics of different influenza virus types, so as to provide the evidence for improving influenza prevention and control measures. Methods: Influenza laboratory testing data for sentinel surveillance of ILI cases in Jiangsu Province from 2019 to 2024 were collected through the China Influenza Surveillance Information System. The positive detection rate of influenza virus was calculated, and descriptive analysis was performed to characterize the distribution of different influenza virus types. Using the farthest neighbor linkage method, influenza virus positive detection rates clustering was analyzed by year and week. Clusters were defined based on inter-cluster distance, and the intensity of the positive detection rate was visualized through color gradients in the clustering heatmap. Results: From 2019 to 2024, a total of 183 878 ILI specimens were collected in Jiangsu Province. Among them, 20 059 specimens tested positive for influenza virus, corresponding to an overall positive detection rate of 10.91%, and an average annual positive detection rate of 10.89%. The primary circulating influenza virus types were influenza A H3N2 subtype, accounting for 40.92%, followed by influenza B Victoria linage at 34.00%, and influenza A H1N1 subtype at 24.80%. Influenza B Yamagata linage was not detected throughout the five-year period. Influenza A H3N2 subtype predominated during two distinct periods: from January to March 2019, and from June 2022 to December 2023. Influenz B Victoria linage was the dominant type from April 2019 to May 2022 and again from January to April 2024. Influenza A H1N1 subtype emerged as the primary type from May to December 2024. Year-based clustering analysis grouped the annual positive detection rates from 2019 to 2024 into three clusters. The closest cluster distance was observed between 2019 and 2024. The highest annual positive detection rate occurred in 2023. Both influenza A H3N2 and H1N1 subtype each formed a single cluster, with their peak positive detection rates also recorded in 2023. Influenza B Victoria lineage was separated into two clusters, with its highest positive detection rate occurring in 2020. Week-based clustering analysis revealed that influenza virus detection was concentrated in weeks 47 to 52 and weeks 1 to 15. More specifically, the positive detection rates for influenza A H3N2 subtype peaked during weeks 30 to 34 and weeks 42 to 52; for influenza A H1N1 subtype, during weeks 9 to 15 and weeks 51 to 52; and for influenza B Victoria lineage, during weeks 1 to 11 and weeks 50 to 52. Conclusions From 2019 to 2024, the average annual positive detection rate of influenza virus in Jiangsu Province remained relatively low. Influenza activity characterized by the alternating circulation of influenza A H1N1 subtype, influenza A H3N2 subtype, and influenza B Victoria linage. It is necessary to maintain the surveillance sensitivity for the influenza B Yamagata lineage.

Abstract Health is the cornerstone of adolescents holistic development and a vital component of the "Healthy China" strategy. The Guidelines on Comprehensively Promoting the Construction of Healthy Schools issued by the Ministry of Education has deployed a systematic layout for healthy school initiatives, marking a new stage of policy implementation and deeper connotation development. Incorporating scientific research related to healthy school construction into the funding framework of the National Science and Technology would not only provide robust research support for policy implementation but also serve as a new growth driver for the advancement of preventive medicine, thereby creating a virtuous cycle of "policy-research-practice". Researchers should proactively seize this policy opportunity, focus on key scientific questions in healthy school construction, rigorously design research protocols, and continuously generate high quality fundamental research findings and translational evidence for application. Such efforts will provide empirical scientific grounds for the thorough implementing the educational philosophy of "health first" and contribute to building a healthy school research and action system with Chinese characteristics.

Objective:To analyze the changes in the prevalence characteristics of multimorbidity among adolescents aged 13-18 in Inner Mongolia Autonomous Region from 2019 to 2022 and to explore the association between multimorbidity and moderate to high-intensity physical activity among them.Methods:A stratified random cluster sampling method was used to select students aged 13-18 in Inner Mongolia Autonomous Region every September from 2019 to 2022. Physical examinations, demographic characteristics, and depression-related surveys were conducted to analyze the multimorbidity of overweight, obesity, high blood pressure, myopia, spinal curvature abnormality, and depression. A logistic regression model was used to analyze the association between multimorbidity and moderate to high-intensity physical activity.Results:From 2019 to 2022, 70 972, 62 923, 80 254, and 78 288 study subjects were included, with the rates of multimorbidity being 56.4%, 55.4%, 57.2%, and 55.8%, respectively. The rates of multimorbidity remained relatively stable from 2019 to 2022 ( χ2=0.06, P=0.950). The incidence of multimorbidity among girls was significantly higher than that among boys ( P<0.001). The incidence of multimorbidity among urban students was significantly higher than that among suburban students ( P<0.001). The incidence of multimorbidity among high school students was higher than that among middle school students ( P<0.001). The top three multimorbidity combinations were myopia and overweight/obesity (26.4%), myopia and high blood pressure (24.4%), and myopia and depression (19.8%), while the least common combination was depression and spinal curvature abnormality (1.1%). The multimorbidity patterns showed no significant differences between years ( χ2=0.03, P=0.999). The multimorbidity status was significantly associated with the status of meeting the standard of moderate to high-intensity physical activity ( OR=0.83, 95% CI: 0.80-0.86). The association was stronger in boys ( OR=0.77, 95% CI: 0.73-0.81) compared with girls ( OR=0.90, 95% CI: 0.85-0.96), with a significant interaction term ( P<0.001). Conclusion:From 2019 to 2022, the incidence of multimorbidity among adolescents aged 13 to 18 in Inner Mongolia Autonomous Region is relatively high, mainly due to the co-occurrence of myopia and other health problems. Adequate physical activity is an important factor in reducing multimorbidity.

Objective:To analyze the epidemiological characteristics of wasting, spinal curvature abnormalities and multimorbidity among children and adolescents aged 6-18 in Inner Mongolia and explore the related factors of these two health problems.Methods:In September 2022, a stratified random cluster sampling method was employed to select 188 635 children and adolescents aged 6-18 in Inner Mongolia for physical examinations and questionnaire surveys. Data on height, weight, as well as dietary behavior, physical activity, classroom environment, academic tasks, writing posture, and screen behavior were collected. The epidemiological characteristics of wasting, spinal curvature abnormalities and multimorbidity were analyzed. Additionally, a multivariate logistic regression model was used to analyze the factors associated with wasting, spinal curvature abnormalities and multimorbidity.Results:A total of 188 635 children and adolescents aged 6-18 years participated in this study, including 95 393 boys (50.6%) with an average age of (11.53±3.32) years. The detection rate of wasting was 3.79%, with a higher detection rate in boys (4.18%) than in girls (3.38%) ( P<0.001). The detection rate of spinal curvature abnormalities was 3.64%, with a higher detection rate in girls (4.04%) than in boys (3.25%) ( P<0.001). The detection rate of multimorbidity between wasting and spinal curvature abnormalities was 0.17%, and there was no statistically significant difference between genders ( P>0.05). The detection rates of wasting, spinal curvature abnormalities, and multimorbidity all increased with age ( P t<0.001). The multivariate logistic regression analysis showed that, after adjusting for gender, age, urban/rural status, and school grade, compared to children and adolescents who exercised ≥1 hour of moderate-to-vigorous physical activity (MVPA) for at least 5 days per week and had daily screen time <2 hours, those who exercised <5 days per week ( OR=1.28, 95% CI: 1.19-1.37) and had daily screen time ≥2 hours ( OR=1.11, 95% CI: 1.03-1.19) had a higher risk of wasting. Compared to children and adolescents who had ≥5 physical education (PE) classes per week, adjusted desk and chair height,<1 hour of after-school study/writing time, and whose parents or teachers rarely or never reminded them about posture, those with <5 PE classes per week ( OR=1.11, 95% CI: 1.02-1.21), unadjusted desk and chair height ( OR=1.08, 95% CI: 1.01-1.15),≥1 hour of after-school study/writing time ( OR=1.15, 95% CI: 1.07-1.24), frequent reminders from parents ( OR=1.16, 95% CI: 1.09-1.23), and frequent reminders from teachers ( OR=1.10, 95% CI: 1.04-1.16) had a higher risk of spinal curvature abnormalities. Compared to children and adolescents who did not consume sugary drinks daily, exercised ≥1 hour of MVPA for at least 5 days per week, and whose teachers rarely or never reminded them about posture, those who consumed sugary drinks daily ( OR=1.61, 95% CI: 1.00-2.46), exercised <5 days per week ( OR=1.33, 95% CI: 1.01-1.79), and had teachers who frequently reminded them about posture ( OR=1.35, 95% CI: 1.05-1.75) had a higher risk of multimorbidity between wasting and spinal curvature abnormalities. Conclusion:The detection rates of wasting, spinal curvature abnormalities and multimorbidity among children and adolescents aged 6-18 in Inner Mongolia are generally low, with an increasing trend observed with age. Both lifestyle and school environmental factors are associated with wasting, spinal curvature abnormalities and multimorbidity.

Objective:To understand the occurrence of different patterns of multimorbidity among children and adolescents aged 9-18 in Tianjin City and analyze the cumulative effects of lifestyle on these patterns of multimorbidity.Methods:From September to November 2022, a stratified cluster random sampling method was used to select students from primary schools, junior high schools, general high schools, and vocational schools in 16 districts of Tianjin to screen for height, weight, blood pressure, distant vision, and diopter. One year later, a follow-up measurement and questionnaire survey were conducted. The log-binomial model was used to analyze the strength of the association between lifestyle factors and different patterns of multimorbidity.Results:The age of 9 488 students was (12.37±2.49) years old, including 4 999 boys and 4 489 girls. The detection rates of three patterns of multimorbidity of overweight obesity and high blood pressure, overweight obesity and myopia, and overweight obesity with high blood pressure and myopia were 6.63%, 9.32%, and 4.21%, respectively. The detection rates of the three types of multimorbidity in boys were higher than those in girls (all P<0.001). The detection rate of overweight obesity and high blood pressure in suburban areas was higher than that in urban areas ( P=0.002). The detection rate of overweight obesity and myopia in suburban areas was lower than that in urban areas ( P=0.034). The detection rate of overweight obesity and myopia among those aged 9-12 years old was higher than other age groups (all P<0.001). The ARR (95% CI) for the association between favorable physical activity and the occurrence of overweight obesity and high blood pressure was 0.79 (0.68-0.92). The ARR (95% CI) for the association between favorable physical activity and the occurrence of overweight obesity with high blood pressure and myopia was 0.82 (0.67-0.99). Compared with children and adolescents with 0-2 favorable lifestyle factors, those with 4-5 favorable lifestyle factors had a lower risk of overweight obesity and high blood pressure ( ARR=0.84, 95% CI: 0.59-0.92). Conclusion:Boys aged 9-18 in Tianjin City are more prone to multimorbidity of overweight obesity and high blood pressure, overweight obesity and myopia, and overweight obesity with high blood pressure and myopia. Children and adolescents with 4-5 favorable lifestyle factors have a reduced risk of occurrence of overweight obesity and high blood pressure. Lifestyle has cumulative effects on multimorbidity of overweight obesity and high blood pressure.

Objective: To investigate the prevalence and associated factors of spinal curvature abnormalities among primary and secondary school students in the Guangxi Zhuang Autonomous Region, so as to provide a scientific basis for the prevention and control of such abnormalities. Methods: From September to November 2023, adopting a stratified cluster random sampling method, spinal curvature screenings and questionnaire surveys were conducted among 168 931 students from grade 4 of primary school to grade 12 of high school in 111 districts and counties across 14 cities in Guangxi. Chi square tests and binary Logistic regression analysis were used to analyze influencing factors of spinal curvature abnormalities. Results: In 2023, the detection rate of poor posture among students above grade 4 in Guangxi was 4.24% , and the detection rate of spinal curvature abnormalities was 2.13%. The detection rate was higher among urban students (2.84%) than rural students (1.66%), boarding students (2.61%) than non-boarding students (1.60%), and high school students (3.16%) than junior high (2.45%) and primary school students (1.15%), and the differences were statistically significant ( χ 2=269.85, 221.44, 565.10, P <0.01). A trend of increasing detection rates with higher grade levels was observed ( χ 2 trend =617.63, P <0.01). Binary Logistic regression analysis indicated that students without boarding at school ( OR =0.82, 95% CI =0.75-0.90), engaging in high-intensity physical activity for over 60 min per day ≥5 days per week ( OR =0.90, 95% CI =0.82-0.98), and adequate sleep ( OR =0.87, 95% CI =0.81-0.94) had lower risks of detecting spinal curvature abnormalities ( P <0.05). Conclusions The prevalence of spinal curvature abnormalities increases with grade level among primary and secondary school students in Guangxi. Regular moderate-to-vigorous physical activity demonstrates protective effects against spinal abnormalities.

Objective: To evaluate the intervention effectiveness of co-occurrence and prevention for myopia and obesity among primary and secondary school students, so as to provide a scientific basis for the development of comprehensive intervention measures in myopia and obesity. Methods: From September 2022 to September 2023, a cluster random sampling method was used to select 6 primary schools and 6 junior high schools from Tongzhou District, Beijing. Participants were randomly assigned to an intervention group (914 before intervention and 754 after intervention) and a control group (868 before intervention and 652 after intervention), with an expected duration of one academic year. Based on the RE-AIM framework, integrate resources from families, schools, communities, and medical institutions to develop a school-based intervention technology packagefor the co-occurrence and prevention of myopia and obesity in children. The intervention group received intervention according to the comprehensive intervention technology package, while the control group did not receive any intervention measures. Relevant health indicators during the baseline period and after intervention were measured and collected, and groups were compared by Chi quest test, t-test and Wilcoxon rank sum test. Results: After intervention, the uncorrected visual acuity of primary and secondary school students in the intervention group (4.79±0.30) and the control group (4.77±0.33) both decreased compared to those before intervention (4.80±0.30, 4.90±0.32) ( t =-7.00,-5.24); the decrease in uncorrected visual acuity in the intervention group was smaller than that in the control group( t =5.33)( P <0.01). After intervention, body mass index, waist circumference, hip circumference, and body fat percentage of primary and secondary school students in the intervention group decreased compared to those before intervention. However, the changes in these indicators were not statistically significant ( t/Z =-0.03, - 0.36，- 0.30，- 0.01, P >0.05); the above indicators in the control group increased compared to those before intervention, but only hip circumference and body fat percentage showed statistically significant changes ( t/Z =2.17, 2.62, P <0.05). After intervention, both the intervention group and the control group showed increases in systolic and diastolic blood pressure compared to those before intervention(intervention group: t =2.16,5.29; control group: t =6.84,5.07); the intervention group had lower systolic and diastolic blood pressure than the control group( t = -5.27 , -2.08)( P <0.05). After intervention, the intervention and the control groups had statistically significant differences in cognitive accuracy(92.48%, 69.33%) in terms of "outdoor exercise can prevent myopia" and "having 5 servings of adult fist sized vegetables and fruits every day" ( χ 2=6.30, 7.86, P <0.05). There was a statistically significant difference in the proportion of primary and secondary school students in the intervention group (40.98%) and the control group (35.43%) for "who did not drink sugary drinks for every day in the past 7 days" ( χ 2=4.32, P <0.05). After intervention, the intervention group and the control group showed increases in "school outdoor activity duration on school days" and "outdoor activity duration on rest days" compared to those before intervention ( t/Z =-13.32,-9.71;- 2.59，-2.69）；the behavior rate of "visual acuity measurement frequency at least once every 3 months" in the intervention group (46.68%) and the control group (52.76%) increased compared to those before intervention (36.43%, 44.01%), and the increases in the intervention group were greater than that in the control group ( χ 2=17.52,11.08) ( P <0.05). Conclusions Comprehensive intervention measures have significant intervention effects on controlling the occurrence and development of comorbidity of myopia and obesity in children. It could actively promote collaboration and cooperation among families, schools, communities and medical institutions to reduce the occurrence of myopia and obesity among primary and secondary school students.

Objective: To explore the comorbidity and associated factors of dental caries and overweight/obesity among primary and secondary school students in Guangxi, so as to provide a scientific basis for the development of targeted prevention strategies. Methods: A stratified cluster random sampling method was used to survey 178 700 students from the fourth grade of primary school to the third year of high school in Guangxi Zhuang Autonomous Region from September to November 2023, including physical examination, oral screening, and questionnaire survey. Chisquare tests and binary Logistic regression analysis were employed to investigate the related factors of the cooccurrence of dental caries and overweight/obesity among students. Results: The comorbidity rate of dental caries and overweight/obesity was 9.55%, with urban areas (9.95%) higher than rural counties (9.24%), boys (10.54%) higher than girls (8.54%), primary school students (11.49%) higher than senior high school students (8.92%) and junior high school students (8.05%), and nonboarding students (11.44%) higher than boarding students (7.94%), and all differences were statistically significant (χ2=26.07, 207.91, 471.54, 629.14,P<0.01). Multivariate Logistic regression analysis showed that consuming cereal for breakfast (OR=0.91, 95%CI=0.88-0.94), drinking milk in the past week (OR=0.89, 95%CI=0.83-0.95), meeting sleep standards (OR=0.95, 95%CI=0.91-0.99), and brushing teeth at least once a day (OR=0.82, 95%CI=0.73-0.93) had a lower risk of the comorbidity of dental caries and overweight/obesity. In contrast, drinking beverages in the past week (OR=1.14, 95%CI=1.09-1.20), consuming fried foods in the past week (OR=1.11, 95%CI=1.06-1.17), eating fruit ≥1 time every day (OR=1.06, 95%CI=1.02-1.11), consuming fruit ≥1 type every day (OR=1.07, 95%CI=1.01-1.12), and having fish, poultry, meat, or eggbased breakfasts (OR=1.03, 95%CI=1.05-1.13) had a higher risk of the comorbidity of dental caries and overweight/obesity (P<0.05). Conclusions Dietary habits and lifestyle behaviors are associated with the comorbidity of dental caries and overweight/obesity among primary and secondary school students in Guangxi. Guiding students to form healthy living habits is helpful to preven dental caries and overweight/obesity.

Objective: To explore the bidirectional associations among body mass index Z scores (BMI Z scores) and weight stigma with depressive symptoms in adolescents, thereby providing evidence for targeted intervention strategies. Methods: A stratified cluster random sampling method was employed to select 18 301 adolescents aged 12-18 years from all 12 prefectures (103 counties) in the Inner Mongolia Autonomous Region, and two waves of longitudinal surveys were conducted in September 2023 (T1) and September 2024 (T2) among the adolescents. Weight stigma was assessed by using a self developed questionnaire, depressive symptom was measured with the Center for Epidemiologic Studies Depression Scale (CES-D), and BMI Z scores were calculated according to the World Health Organization standards. Pearson correlation analysis was used to examine associations among variables, and cross lagged panel models were constructed to investigate the dynamic bidirectional relationships among the three variables. Results: Adolescents BMI Z scores and weight stigma with depressive symptoms all exhibited autoregressive stability across the two time points (autoregressive paths, all P <0.01). Cross lagged model comparisons indicated that the bidirectional path model achieved the best fit ( χ 2=12.65, RMSEA =0.017, CFI =1.000; △ χ 2=193.39, P <0.01), supporting dynamic bidirectional associations among the three variables. After adjusting for gender, age, subjective social status and only child status, T1 BMI Z scores among adolescents positively predicted T2 weight stigma ( β =0.061), and T1 weight stigma positively predicted T2 depressive symptoms ( β =0.608); in the reverse direction, T1 depressive symptoms predicted T2 weight stigma ( β =0.003), and T1 weight stigma predicted T2 BMI Z scores ( β =0.081) (all P <0.01). Conclusions There is a bidirectional cross lagged relationship among adolescents BMI Z scores and weight stigma with depressive symptoms, suggesting that weight stigma may serve as a key psychological variable linking obesity and depressive symptoms. Greater attention should be paid to the potential threat of weight stigma to adolescents mental health, with intervention strategies expanded from a solely physiological focus to encompass psychosocial dimensions.

Objective:To analyze the changes in the prevalence characteristics of multimorbidity among adolescents aged 13-18 in Inner Mongolia Autonomous Region from 2019 to 2022 and to explore the association between multimorbidity and moderate to high-intensity physical activity among them.Methods:A stratified random cluster sampling method was used to select students aged 13-18 in Inner Mongolia Autonomous Region every September from 2019 to 2022. Physical examinations, demographic characteristics, and depression-related surveys were conducted to analyze the multimorbidity of overweight, obesity, high blood pressure, myopia, spinal curvature abnormality, and depression. A logistic regression model was used to analyze the association between multimorbidity and moderate to high-intensity physical activity.Results:From 2019 to 2022, 70 972, 62 923, 80 254, and 78 288 study subjects were included, with the rates of multimorbidity being 56.4%, 55.4%, 57.2%, and 55.8%, respectively. The rates of multimorbidity remained relatively stable from 2019 to 2022 ( χ2=0.06, P=0.950). The incidence of multimorbidity among girls was significantly higher than that among boys ( P<0.001). The incidence of multimorbidity among urban students was significantly higher than that among suburban students ( P<0.001). The incidence of multimorbidity among high school students was higher than that among middle school students ( P<0.001). The top three multimorbidity combinations were myopia and overweight/obesity (26.4%), myopia and high blood pressure (24.4%), and myopia and depression (19.8%), while the least common combination was depression and spinal curvature abnormality (1.1%). The multimorbidity patterns showed no significant differences between years ( χ2=0.03, P=0.999). The multimorbidity status was significantly associated with the status of meeting the standard of moderate to high-intensity physical activity ( OR=0.83, 95% CI: 0.80-0.86). The association was stronger in boys ( OR=0.77, 95% CI: 0.73-0.81) compared with girls ( OR=0.90, 95% CI: 0.85-0.96), with a significant interaction term ( P<0.001). Conclusion:From 2019 to 2022, the incidence of multimorbidity among adolescents aged 13 to 18 in Inner Mongolia Autonomous Region is relatively high, mainly due to the co-occurrence of myopia and other health problems. Adequate physical activity is an important factor in reducing multimorbidity.