Objective: To evaluate the prevalence and future trend of change of the disease burden of injuries in Chinese children and adolescents from 1990 to 2021, so as to provide reference for injury prevention and control in this population. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 (GBD 2021), the trend of change in the disease burden of injuries in children and adolescents in China from 1990 to 2021 was analyzed by the Joinpoint regression model. The Bayesian age period cohort model (BAPC) was used to predict the disease burden of injuries among children and adolescents in China from 2022 to 2031. Results: From 1990 to 2021, the standardized incidence rate, standardized prevalence rate, standardized mortality rate, and standardized disability adjusted life years (DALYs) rate of injuries among children and adolescents in China showed an overall downward trend (AAPC=-1.14%, -0.76%, -5.41%, -5.03%, P <0.05). For different genders, the standardized incidence rate (7 106.00/100 000, 5 388.00/100 000), standardized mortality rate (92.00/100 000, 19.00/ 100 000 ), and standardized DALYs rate (7 834.00/100 000, 1 673.00/100 000) of injuries in boys were higher than the rate of injuries in girls in 1990 and 2021 (5 188.00/100 000, 3 874.00/100 000; 61.00/100 000, 10.00/100 000; 5 398.00/100 000, 945.00/100 000). Compared with Asia and globally, China had the fastest decline in the standardized mortality rate (AAPC= -5.41 ) and the slowest decline in the standardized prevalence rate (AAPC=-0.76) among children and adolescents. The results of the Joinpoint burden trend analysis demonstrated that the standardized incidence rate of injuries showed an increasing trend from 2005 to 2021, and the standardized prevalence rate of injuries showed an increasing trend from 2006 to 2021. Among the different age groups, the disease burden of injuries was highest in the 15-19-year-old group in 2021. For different types of injuries, the standardized incidence rate, standardized mortality rate, and standardized DALYs rate of unintentional injury were higher than those of transport injury, and self harm and interpersonal violence from 1990 to 2021. The BAPC prediction model showed that the standardized incidence rate ( 4 833.05/ 100 000-5 313.70/100 000) and standardized prevalence rate (5 433.90/100 000-5 821.88/100 000) of injury showed an increasing trend, and the standardized mortality rate (13.69/100 000-5.52/100 000) and the standardized DALYs rate ( 1 226.37/ 100 000-510.14/100 000) showed a decreasing trend during 2022-2031. The analysis of influencing factors found that children and adolescents who drank alcohol were at high risk of injury burden. Conclusions From 1990 to 2021, the injury burden of children and adolescents in China generally showed a downward trend. The standardized incidence rate and standardized prevalence rate of injuries are predicted to increase from 2022 to 2031. More targeted and individualized intervention measures should be developed to reduce the injury burden in children and adolescents.

Objective: To understand the growth and development levels of four physical measurements in children aged 3-6 years in China, so as to provide a reference for child nutrition improvement and health promotion. Methods: A stratified random sampling method was used to collect physical measurement data from 120 kindergartens 25 842 children aged 3-6 years across 24 provinces and cities in seven natural geographical regions of North China, Northeast China, East China, Central China, South China, Southwest China and Northwest China from 2020 to 2023. The development levels of head circumference, chest circumference, waist circumference, and hip circumference were evaluated using a grading method. The analysis of gender and age differences was conducted using Mann-Whitney U- test and Kruskal-Wallis test, and the comparison of abnormal detection rates for different genders was conducted using Chi square test. Results: The distribution range of children aged 3-6 was 51.74(50.08, 53.33) cm in terms of head circumference, 55.73(52.09, 59.04) cm in terms of chest circumference, 53.04(48.92, 56.40) cm in terms of waist circumference, and 59.36(56.30, 62.32) cm in terms of hip circumference. The detection rate of abnormal head circumference in boys and girls aged 3-6 years old was relatively high (19.71%-42.02%), and the detection rate of abnormal physical circumference development levels in boys was higher than that in girls of all ages ( χ 2=5.63-83.35, P <0.05). The detection rate of abnormal hip circumference (4.89%-6.53%) and chest circumference (4.51%-6.38%) in boys and girls aged 3-6 was relatively low, and there was no statistically significant difference in the abnormal rate between different ages and genders ( χ 2=0.00-1.61, 0.00-3.71, P >0.05). The detection rate of abnormal waist circumference in boys and girls aged 3-6 was relatively high (13.70%-42.45%), and the detection rate of abnormal waist circumference in girls was higher than that in boys aged 4-6 groups ( χ 2=10.49-58.18, P < 0.05). Conclusions The overall physical development of children aged 3-6 years in China is improving, but the abnormal detection rates for head circumference and waist circumference are relatively high. Child healthcare should focus on preventing and treating abdominal obesity, with differentiated health intervention strategies based on different age groups and genders.

Objective: To analyze the time varying characteristics of weight among Han primary and secondary school students in Xinjiang from 1985 to 2019, so as to provide a scientific basis for formulating nutrition policies for adolescents in ethnic minority areas. Methods: Weight data of Han primary and secondary school students aged 7-18 in Xinjiang from the National Student Physical Fitness and Health Survey from 1985 to 2019 were selected. Statistical analysis was conducted by using general linear model test, one way ANOVA and t-test. The weight development trends in 2025 and 2030 were predicted through time series analysis. Results: From 1985 to 2019, the weight of Han Chinese boys and girls from primary and secondary schools in Xinjiang showed a continuous upward trend (boys: B =0.25,girls: B =0.16, P <0.01). There were statistically significant differences in weight between boys and girls aged 7-18 in different years (boys: F =102.35-142.05, girls: F =98.03-140.59, P <0.01). Compared with 1985, the weight of urban boys and girls increased by 11.92 and 7.95 kg in 2019, as well as rural boys and girls by 11.36 and 5.61 kg, and the average weight gain of urban students was greater than that of rural students. From 1985 to 2019, the weight of urban boys and girls were higher than that of rural boys and girls (boys: t =30.12-37.55, girls: t =30.12-38.64, P <0.01). In 2005, the weight difference between urban and rural boys and girls was the largest, at 4.23 and 2.32 kg. The average weight of boys and girls in the age groups of 7-18 would continue to increase in 2025 and 2030; compared with 2019, the 7-year old age group for boys and the 17-year old age group for girls would have the largest growth in 2030 by 2.29 and 3.75 kg. Conclusions From 1985 to 2019, the weight of students aged 7-18 in Xinjiang showed an upward trend, and the weights of both boys and girls would gradually increase in 2025 and 2030. Attention should be paid to students physical health and adopt comprehensive measures to prevente overweight and obesity.

Objective: To evaluate the accuracy of body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) in screening true obesity among children, so as to provide a scientific basis for precise screening and early prevention and control of childhood obesity. Methods: A total of 1 322 children aged 10-15 years old were surveyed by the Huantai Children Cardiovascular Health Cohort in 2021. Fat mass percentage (FMP) and fat mass index (FMI) were measured by bioelectrical impedance analysis, with FMP or FMI values at or above the age and sex-specific 70th percentiles as the criteria for defining true obesity. BMI, WC and WHtR were used to define general obesity and central obesity. The accuracy of these measures in screening for true obesity was evaluated by calculating the missed diagnosis rate, misdiagnosis rate, area under the curve(AUC) for receiver operating characteristic and Kappa coefficient. Results: Boys had higher BMI [(21.79±4.56) kg/m 2], WC [(76.41±12.53) cm] and WHtR (0.47±0.07) than girls [(20.83±4.13) kg/m 2, (70.69±10.06) cm, (0.45±0.06)] ( t =4.02, 9.19, 6.63), while boys had lower FMP [(18.29±8.35)%] and FMI [(4.35±2.79) kg/m 2] than girls [(24.87±6.51)%, (5.44±2.53) kg/m 2] ( t =-16.10,-7.42) ( P <0.01). Using FMP as a reference standard, the diagnosis error rates of screening for true obesity based on BMI, WC and WHtR were 12.24%, 2.11% and 2.11%, respectively; the diagnosis error rates were 10.88%, 27.28% and 24.33%; the AUC values were 0.88, 0.85 and 0.87; the Kappa coefficients were 0.67, 0.48 and 0.52. Using FMI as a reference standard, rates of BMI, WC and WHtR screening for true obesity were 14.20%, 1.23% and 2.78%; the diagnosis error rates were 4.81%, 20.84% and 18.14 %; the AUC values were 0.90, 0.89 and 0.90; the Kappa coefficients were 0.81, 0.64 and 0.67. Conclusions BMI has a higher diagnosis error rate in screening for true obesity in children, while WC and WHtR have higher diagnosis error rates. It is recommended to promote body fat assessment in clinical practice, so as to achieve more accurate prevention and control of chronic diseases.

Problem: Despite the widespread use of designated quarantine hotels to minimize the transmission of COVID-19 from imported cases, there is scant literature on the infrastructure and operational requirements of such facilities. Context: Travellers to Hong Kong Special Administrative Region (SAR) (China) were required to undergo quarantine in designated hotels for up to 21 days. Prior to operation, all these hotels were modified and hotel staff received structured training in infection control practices. Action: We conducted retrospective reviews of the procedures and operational protocols that were followed to convert and manage commercial hotels as quarantine hotels during the early part of the pandemic. We also reviewed the training provided and compliance monitoring. Finally, we reviewed intra-hotel outbreak investigations that were conducted between April 2021 and June 2022. Outcome: Designated quarantine hotels received 842 510 quarantined travellers from December 2020 to October 2022. Ten outbreaks were reported, affecting 28 guests (0.003%) and two staff. Prompt epidemiological investigation and action stopped further transmission. Discussion: In Hong Kong SAR (China), designated quarantine hotels successfully minimized COVID-19 transmission from imported cases to the community and should be considered as part of integrated response plans for future pandemics. Based on our COVID-19 pandemic experience, we recommend specifying requirements for quarantine centres and hotels to ensure adequate ventilation inside guest rooms and corridors, functioning drainage systems and the adoption of stringent infection control practices. We also recommend the installation of closed-circuit television cameras in all common areas to support compliance monitoring and outbreak investigation.

Objective: To analyze the temporal variation patterns of sickness absenteeism among primary and secondary school students in Shanghai, so as to explore models suitable for predicting peaks and intensity of absenteeism rates. Methods: The seasonal and trend decomposition using loess (STL) method was used to analyze the seasonal and long term trend changes in sickness absenteeism among primary and secondary school students from September 1 in 2010 to June 30 in 2018, in Shanghai. A hierarchical clustering method based on Dynamic Time Warping (DTW) was employed to classify absenteeism symptoms with similar temporal patterns. Based on historical data, the study constructed and evaluated different time series algorithms and machine learning models to optimize the accuracy of predicting the trend of sickness absenteeism. Results: During the research period, the average new absenteeism rate due to illness was 16.86 per 10 000 person day for every academic year, and the trend of sickness absenteeism exhibited both seasonality and a long term upward trend, reaching its highest point in the 2017 academic year (22.47 per 10 000 person day). The symptoms of absenteeism were divided into three categories: high incidence in winter and spring (respiratory symptoms, fever and general discomfort, etc.), high incidence in summer (eye symptoms, nosebleeds, etc.) and those without obvious seasonality (skin symptoms, accidental injuries, etc.).The constructed time series models effectively predicted the trend of absenteeism due to illness, although the accuracy of predicting peak intensity was relatively low. Among them, the multi layer perceptron (MLP) model performed the best, with an root mean squared error (RMSE) of 8.96 and an mean absolute error (MAE) of 4.37, reducing 36.51% and 39.02% compared to the baseline model. Conclusion Time series models and machine learning algorithms could effectively predict the trend of sickness absenteeism, and corresponding prevention and control measures can be taken for absenteeism caused by different symptoms during peak periods.

Objective: To explore the relationship between visual acuity and physical fitness of university freshmen, so as to provide reference for myopia prevention and control for freshmen. Methods: From October to November 2022, 2 160 college freshman without majoring in public safety administration, selected from Guangxi Police College in 2022 by using the stratified cluster random sampling method, were reviewed for the results of visual acuity test and physical fitness scores. The physical fitness indices were evaluated by using the Z scores of physical fitness test scores, and the strength of association between the level of physical fitness index and myopia was analyzed by using Logistic regression model. Results: Among 2 160 college freshman without majoring in public safety administration, 917 (42.5%) students were diagnosed screening myopia, including 66 (3.1%) cases of high myopia, 383 (17.7%) cases of moderate myopia and 468 (21.7%) cases of mild myopia. The differences in the distribution of visual acuity tests among students with different physical fitness indices, body mass index, and gender were statistically significant ( Z/H=54.50, 49.53, 15.51, P <0.01). Low level and low middle level physical fitness indices were associated with screening myopia among freshmen[ OR (95% CI )=2.81(1.93-4.08),1.87(1.38-2.54)], and low level physical fitness indexes were associated with high myopia [ OR (95% CI )=7.22(2.33-22.32)] ( P <0.01). Conclusions Screening myopia among college freshman without majoring in public safety administration is related to physical fitness, and low level and low middle level physical fitness index are risk factors for myopia. Improving the level of physical fitness might be effective in preventing myopia.

Objective: To analyze respiratory syncytial virus(RSV) outbreaks surveillance results and the epidemiological characteristics in kindergarten and school in Shenzhen during 2017-2023 , so as to provide a scientific reference for control and prevention of RSV. Methods: Epidemiological data and surveillance results of RSV outbreaks in kindergarten and school from 2017 to 2023 were collected for descriptive analyses. Results: A total of 31 RSV outbreaks were identified in kindergarten and school in 2017-2023 in Shenzhen, 346 cases were reported, the average incidence rate was 22.02%. The most annual RSV outbreaks were reported in 2020 with 14 outbreaks, followed by 8 outbreaks in 2023. A total of 64.52% of RSV outbreaks were identified in kindergarten with rest occurring in primary school or middle school. The greatest monthly count of outbreak was 18 (58.06%) in September, followed by 3 outbreaks (9.68%) in March and October. A total of 244 swab samples were collected, 169 samples were positive for respiratory viruses, the positive rate was 69.26%, 121 samples were positive for RSV,from 31 respiratory syncytical virus outbreaks 57 and samples were positive for other respiratory viruses(9 samples were positive for two respiratory viruses). A toral of 14(45.16%) outbreaks are caused by RSV alone, 17 outbreaks (54.84%) were caused by RSV and other respiratory viruses. Conclusions Most RSV outbreaks in kindergarten and school are reported after 2020 in Shenzhen, most RSV outbreaks occur in kindergarten, peak seasons of RSV outbreaks are autumn and spring.

Objective: To construct a scientific and perfect evaluation index system of infectious disease prevention and control ability in colleges and universities, so as to provide reference tools for colleges and universities to effectively respond to infectious disease. Methods: The initial framework of the evaluation index system of infectious disease prevention and control ability in colleges and universities was constructed by using literature analysis method. Experts familiar with infectious disease prevention and control or school health work were selected to conduct two rounds( n =16，18) of Delphi expert consultation for determining the evaluation index system. Analytical hierarchy process was used to calculate the index weights and combined weights. About 198 prevention and control personnel were conveniently selected from 3 universities in Inner Mongolia Autonomous Region to comprehensively evaluate the evaluation indicators by using fuzzy comprehensive evaluation method. Results: After two rounds of Delphi consultation questionnaire, the effective recovery rates were 80.0% and 90.0%, the expert authority levels were 0.89 and 0.86, the expert harmony coefficients for Kendall W were 0.166 and 0.310, and the variation coefficient of each index was <0.25. Finally, the evaluation index system of infectious disease prevention and control ability of colleges and universities included 4 first level indicators, 14 second level indicators and 75 third level indicators. The weights of prevention and monitoring and early warning, organizational system guarantee, emergency management, rehabilitation and summary were 0.176, 0.476, 0.268 and 0.080, respectively. The top 3 weights of the secondary indexes were 0.623 for infectious disease surveillance and early warning, 0.595 for loss assessment and 0.370 for emergency response. The score of fuzzy comprehensive evaluation of the index system of infectious disease prevention and control ability in colleges and universities was 79.148, suggesting a high level. Conclusion The established evaluation index system of infectious disease prevention and control ability in colleges and universities is scientific and reasonable, which is conducive to provide tool reference for the evaluation of infectious disease prevention and control ability in colleges and universities.

Objective: To understand the current situation and related factors of screening myopia among students in special education schools, so as to provide evidence for promoting the health level of this population. Methods: From November 2021 to December 2023, a total of 281 students from 6 special education schools in 5 districts of Tianjin were selected by cluster random sampling method for computer optometry visual acuity examination for non ciliary paralysis and questionnaire survey. Multiple Logistic regression was performed to analyze the influencing factors of screening myopia among special education students. Results: The screening myopia detection rate among these special education students in Tianjin was 27.0%, and the screening myopia detection rates of students with autism, developmental delays, and intellectual disabilities were 22.4%, 12.5%, and 33.0%, respectively. The degree of myopia increased with age ( χ 2 trend =22.65, P <0.01). Multivariate Logistic regression analysis showed that age(10-13 years old: OR =5.40, 14-17 years old: OR =8.40, 18-23 years old: OR =6.02), accommodation(non resident: OR =0.29), daily mobile phone usage ≥2 hours ( OR =2.37), and daily computer/tablet usage ≥2 hours ( OR =2.70) were the risk factors for screening myopia among special education students ( P <0.05). Conclusions The detection rate and degree of screening myopia increase with age in special education students. Prolonged screen time exposure is a primary risk factor for screening myopia in special education students. Effective myopia prevention and control strategies should be designed according to the characteristics of special education students.