Objective: To analyze the epidemiological characteristics of category C intestinal infectious diseases among children and adolescents in Shenzhen from 2012 to 2024 and the association with meteorological factors, so as to provide a scientific basis for the targeted prevention and control of infectious diseases for children and adolescents. Methods: Using data from the "Infectious Disease Reporting Information Management System" of the "China Disease Prevention and Control Information System" covering the period from January 1, 2012 to December 31, 2024, the study analyzed clinical and confirmed cases of hand, foot, and mouth disease, other infectious diarrhea, and acute hemorrhagic conjunctivitis among individuals aged 6-19 years old to describe demographic and temporal characteristics. It used Joinpoint regression to calculate the average annual percent change (AAPC) and annual percent change (APC) to analyze incidence trends, and Spearman s correlation was combined to generalize linear models so as to assess the association between category C intestinal infectious diseases and meteorological factors. Results: From 2012 to 2024, a cumulative total of 61 019 cases of hand, foot, and mouth disease among children and adolescents, 58 498 cases of other infectious diarrhea, and 6 377 cases of acute hemorrhagic conjunctivitis were reported. The AAPC in the incidence rates of these three diseases was 19.19%, 31.03% and 31.48 %, respectively(all P <0.05). Notably, the incidence of hand, foot, and mouth disease increased significantly after 2022 (APC= 133.66 %, P <0.01). The temporal distribution showed that hand,foot,and mouth disease was most prevalent in May,June and July (seasonal index of 2.39,3.64,1.97), other infectious diarrhea was most prevalent in February,March and December (seasonal index of 1.22,1.25,1.47), and acute hemorrhagic conjunctivitis peaked in September and October (seasonal index of 4.22,2.16). Monthly average temperature could increase the risk of hand,foot,and mouth disease( β = 0.18 ,95% CI =0.11-0.25); as monthly average wind speed increased, the incidence of other infectious diarrhea ( β =-0.86, 95% CI = -1.50 to -0.22) and acute hemorrhagic conjunctivitis ( β =-1.32, 95% CI =-2.60 to -0.05) both decreased (all P < 0.05 ). Conclusions Among children and adolescents in Shenzhen, category C intestinal infectious diseases remain prevalent throughout the year；the number of reported hand, foot, and mouth disease cases has shown an upward trend in recent years.Temperature and wind speed significantly affect the number of reported cases of three types with category C intestinal infectious diseases.

Objective: To analyze the epidemiological characteristics of varicella among nursery children in Shenzhen from 2015 to 2024, and to evaluate the impact of optimizing varicella vaccine (VarV) immunization strategies on varicella incidence. Methods: Varicella incidence data for nursery children in Shenzhen from 2015 to 2024 were obtained from the China Disease Prevention and Control Information System. The study period was divided into three phases:one dose self pay VarV (January 2015 to October 2017), two dose self pay VarV (November 2017 to October 2019), and two dose free VarV (November 2019 to December 2024). Interrupted time series (ITS) analysis was conducted to assess changes in the level and trend of varicella incidence associated with each phase of policy implementation. Results: A total of 27 517 varicella cases was reported among nursery children from 2015 to 2024, with an average annual incidence of 514.01/100 000. During the same period, 136 clustered outbreaks were reported in nursery institutions, involving a cumulative total of 1 091 cases. ITS analysis showed that during the self pay 1 dose stage, the varicella incidence among nursery children showed an upward trend, with an average monthly increase of 2.58/100 000 (95% CI =2.21/ 100 000 -2.95/100 000, P <0.01). After the implementation of the self pay 2 dose strategy, the incidence decreased, with a change in incidence of -26.12/100 000 (95% CI =-37.30/100 000 to -14.94/100 000) and a change in slope of -2.65/100 000 (95% CI = -3.38/100 000 to -1.93/100 000)(all P <0.01). After the implementation of the free 2 dose strategy, the incidence decreased further, with a change in incidence of -40.03/100 000 (95% CI =-50.39/100 000 to -29.66/100 000, P <0.01) and a change in slope of -0.56/100 000 (95% CI =-1.20/100 000-0.08/100 000, P =0.09). Conclusion The gradual optimization of the VarV vaccination strategy in Shenzhen from self pay 1 dose to free 2 dose has significantly reduced the varicella incidence among nursery children, demonstrating good short term control and long term intervention effectiveness.

Objective:To analyze the spatiotemporal correlation between the surveillance data of influenza in students reported by medical institutions and school absenteeism due to illness, and evaluate the application of Bayesian Structural Time Series model (BSTS) in the prediction of school influenza epidemic.Methods:A total of 13 schools in Dapeng new district of Shenzhen were selected. The incidence data of influenza in schools in Shenzhen from January 1, 2015 to December 31, 2019 were collected from China Disease Control and Prevention Information System and the illness related school absentence data during this period were collected from Shenzhen Student Health Surveillance System, and the spatiotemporal correlation between the data from two systems was analyzed and compared. BSTS was used to make long-term predictions of the monthly incidence of influenza in students in 2019 and short-term predictions of the weekly incidence of influenza in week 1-8 and week 45-52 of 2019 by using the data from two systems.Results:There was a temporal correlation between the data from China Disease Control and Prevention Information System and the data from Shenzhen Student Health Surveillance System ( r=0.93, P<0.001), and the lag of the former one was 1 day ( r=0.73, P<0.001). Influenza outbreaks were randomly distributed in different schools in Shenzhen, and there was no spatial correlation. The root mean square error ( RMSE) and mean absolute error ( MAE) were 0.35 and 0.28, respectively, in the long-term prediction, and the RMSE was 0.33 and 0.34, and the MAE was 0.26 and 0.28, respectively, in the short-term predictions of week 1-8 and week 45-52 of 2019, respectively, showing good prediction accuracy and fitting effect. Conclusion:By analyzing the data from China Disease Control and Prevention Information System and Shenzhen Student Health Surveillance System with BSTS, the dynamics of the school influenza epidemic can be accurately predicted, and effective technical support can be provided for the early warning and prevention and control of influenza epidemic.

Objective:To analyze the temporal distribution of other infectious diarrhea (OID) in Shenzhen and provide evidence for the prevention and control of OID.Methods:The incidence data of OID in Shenzhen from 2011 to 2023 were collected. The seasonal and trend decomposition using loess (STL), seasonal index method, concentration degree and circular distribution method were used to analyze the incidence trend and temporal distribution of OID.Results:A total of 477 611 cases of OID were reported in Shenzhen from 2011 to 2023, with an average annual incidence rate of 260.19/100 000 showing a fluctuating upward trend. The seasonal index method indicated that October-January was period with high incidence of OID in Shenzhen and the seasonal intensity began to decrease in 2020. STL revealed an obvious incidence peak in winter. The concentration method showed that OID had a certain seasonality before 2018 except 2016, but the seasonality was not obvious after 2018. The circular distribution results showed that r was 0.05, mean angle ā was 1.92° and angular standard deviation s was 141.93° ( Z=1 033.37, P<0.001), with the peak on January 1 st and the high incidence period from August 11 th to May 25 th. Conclusions:OID had a certain degree of seasonality in Shenzhen, with an obvious incidence peak in winter. Since the seasonal intensity of OID decreased after 2018, the surveillance, early warning and risk assessment of OID should be continued, and prevention and control measures should be adjusted timely according to the change in the characteristics of the epidemic.

Objective:To analyze the spatiotemporal correlation between the surveillance data of influenza in students reported by medical institutions and school absenteeism due to illness, and evaluate the application of Bayesian Structural Time Series model (BSTS) in the prediction of school influenza epidemic.Methods:A total of 13 schools in Dapeng new district of Shenzhen were selected. The incidence data of influenza in schools in Shenzhen from January 1, 2015 to December 31, 2019 were collected from China Disease Control and Prevention Information System and the illness related school absentence data during this period were collected from Shenzhen Student Health Surveillance System, and the spatiotemporal correlation between the data from two systems was analyzed and compared. BSTS was used to make long-term predictions of the monthly incidence of influenza in students in 2019 and short-term predictions of the weekly incidence of influenza in week 1-8 and week 45-52 of 2019 by using the data from two systems.Results:There was a temporal correlation between the data from China Disease Control and Prevention Information System and the data from Shenzhen Student Health Surveillance System ( r=0.93, P<0.001), and the lag of the former one was 1 day ( r=0.73, P<0.001). Influenza outbreaks were randomly distributed in different schools in Shenzhen, and there was no spatial correlation. The root mean square error ( RMSE) and mean absolute error ( MAE) were 0.35 and 0.28, respectively, in the long-term prediction, and the RMSE was 0.33 and 0.34, and the MAE was 0.26 and 0.28, respectively, in the short-term predictions of week 1-8 and week 45-52 of 2019, respectively, showing good prediction accuracy and fitting effect. Conclusion:By analyzing the data from China Disease Control and Prevention Information System and Shenzhen Student Health Surveillance System with BSTS, the dynamics of the school influenza epidemic can be accurately predicted, and effective technical support can be provided for the early warning and prevention and control of influenza epidemic.

Objective:To analyze the temporal distribution of other infectious diarrhea (OID) in Shenzhen and provide evidence for the prevention and control of OID.Methods:The incidence data of OID in Shenzhen from 2011 to 2023 were collected. The seasonal and trend decomposition using loess (STL), seasonal index method, concentration degree and circular distribution method were used to analyze the incidence trend and temporal distribution of OID.Results:A total of 477 611 cases of OID were reported in Shenzhen from 2011 to 2023, with an average annual incidence rate of 260.19/100 000 showing a fluctuating upward trend. The seasonal index method indicated that October-January was period with high incidence of OID in Shenzhen and the seasonal intensity began to decrease in 2020. STL revealed an obvious incidence peak in winter. The concentration method showed that OID had a certain seasonality before 2018 except 2016, but the seasonality was not obvious after 2018. The circular distribution results showed that r was 0.05, mean angle ā was 1.92° and angular standard deviation s was 141.93° ( Z=1 033.37, P<0.001), with the peak on January 1 st and the high incidence period from August 11 th to May 25 th. Conclusions:OID had a certain degree of seasonality in Shenzhen, with an obvious incidence peak in winter. Since the seasonal intensity of OID decreased after 2018, the surveillance, early warning and risk assessment of OID should be continued, and prevention and control measures should be adjusted timely according to the change in the characteristics of the epidemic.

From June 16 to 30, 2023, men who have sex with men (MSM) who had visited Voluntary Counseling Testing (VCT) clinics in the Luohu, Futian and Nanshan districts of Shenzhen were included in this study to analyze their awareness of Mpox and the influencing factors. The mean age of the 262 MSM was (34.78±8.94) years, with the majority being unmarried (75.2%) and 79.0% confirmed to be infected with HIV. The awareness rates for five primary indicators, current status of Mpox, pathogen and source of infection, mode of transmission, population susceptibility, clinical manifestations and treatment were 68.4%, 84.7%, 60.3%, 87.8%, and 52.5%, respectively. The awareness rates for five secondary indicators, earliest transmission location (44.7%), main mode of transmission (54.2%), role of masks (46.9%), drug accessibility (46.6%), and self-limiting nature (38.2%) were all below 60%. The MSM population in Shenzhen perceived their likelihood of being infected (2.76±1.32) and discriminated against (3.87±1.26) as relatively low. The logistic analysis showed that the high school or vocational school education ( OR:3.094, 95 %CI:1.180-9.299), college or above education ( OR:5.360, 95% CI:2.159-15.501), and higher scores on questions affecting learning or work ( OR:2.196, 95% CI:1.409-3.599) were promoting factors for Mpox awareness, while higher scores on questions concerning the possibility of Mpox mortality ( OR:0.591, 95% CI:0.432-0.791) was the hindering factor for Mpox awareness.

Objective To provide a theoretical basis for radiation health supervision through an analysis of the situation of computed tomography (CT) equipment quality control and CT room radiological protection in Guangdong Province, China in recent years. Methods We collected the data of 392 times of CT quality control and radiological protection testing by a third-party radiological health technical service institution in Guangdong Province from 2019 to 2021. We analyzed the levels of CT-owning hospitals, CT manufacturers, CT quality control test results, and the pass rate of radiation protection tests. Results The examined CT scanners were from different levels of hospitals in Guangdong Province, and were manufactured by nine major CT equipment manufacturers at home and abroad. The pass rate of CT room radiological protection was 99.88%, and the ambient dose equivalent rates of five monitoring points exceeded the limit, with four at the control room door and one at the shield wall of the room. The overall pass rate of CT equipment quality control was 99.49%, and the non-conforming parameters were the accuracy of positioning light and the deviation of reconstructed slice thickness. Conclusion In recent years, CT equipment quality control and room radiation protection in Guangdong Province have been at a high level.

Objective To analyze epidemiological characteristics and changing trends of common respiratory infectious diseases among 6-19 year-old population in Shenzhen from 2013 to 2021, and to provide a reference for prevention and control. Methods Data of influenza, mumps and varicella reported cases among the population aged 6-19 years in Shenzhen from 2013 to 2021 were collected, and descriptive methods and Joinpoint regression model were used to analyze epidemiological characteristics and trends of incidences. Results Between 2013 and 2022 in Shenzhen, the average annual incidence rates of influenza, mumps, and varicella among the population aged 6-19 years were 961.44/100 000, 157.70/100 000, and 664.34/100 000 respectively. The incidence of influenza showed an upward trend in 10 years, with an annual percent change (APC) of 52.88% (P<0.05). The incidence of mumps and varicella both showed an 'up-down' trend, with an inflection point in 2019. The incidence APC of mumps were 11.51% and -43.49%, respectively (P>0.05), while the incidence APC of varicella were 28.88% and -50.03%, respectively (P<0.05), respectively. From the point of seasonal distribution, the incidence of three infectious diseases all showed bimodal distribution, with peaks in winter (December to January of the following year) and at the turn from spring to summer (April to June). The proportion of reported cases of three infectious diseases among people aged 6-<10 years old exceeded 60%. The proportion of varicella cases among people aged 10-<15 and 15-19 was on the rise. The incidence rate of influenza and varicella in people aged 15-19 years increased fastest, with APCs of 77.89% and 33.00%, respectively (both P<0.05). Conclusions The trend analysis based on Joinpoint regression model displayed that the reported incidence of influenza among people aged 6-19 years in Shenzhen during 2013-2022 showed an upward trend, and the incidence of varicella had an 'up-down' trend. Children aged 6-<10 years old are the main incidence group, and the prevention and control of infectious diseases in primary schools should be further promoted. Meanwhile, the rapid rise in the incidence of respiratory infectious diseases among people aged 15-19 years old and the increase in the proportion of varicella cases among people aged 10-19 years old suggest that intervention should be carried out to address the influential factors such as immunization gaps and concentrated accommodation in the older age group of minors.

From June 16 to 30, 2023, men who have sex with men (MSM) who had visited Voluntary Counseling Testing (VCT) clinics in the Luohu, Futian and Nanshan districts of Shenzhen were included in this study to analyze their awareness of Mpox and the influencing factors. The mean age of the 262 MSM was (34.78±8.94) years, with the majority being unmarried (75.2%) and 79.0% confirmed to be infected with HIV. The awareness rates for five primary indicators, current status of Mpox, pathogen and source of infection, mode of transmission, population susceptibility, clinical manifestations and treatment were 68.4%, 84.7%, 60.3%, 87.8%, and 52.5%, respectively. The awareness rates for five secondary indicators, earliest transmission location (44.7%), main mode of transmission (54.2%), role of masks (46.9%), drug accessibility (46.6%), and self-limiting nature (38.2%) were all below 60%. The MSM population in Shenzhen perceived their likelihood of being infected (2.76±1.32) and discriminated against (3.87±1.26) as relatively low. The logistic analysis showed that the high school or vocational school education ( OR:3.094, 95 %CI:1.180-9.299), college or above education ( OR:5.360, 95% CI:2.159-15.501), and higher scores on questions affecting learning or work ( OR:2.196, 95% CI:1.409-3.599) were promoting factors for Mpox awareness, while higher scores on questions concerning the possibility of Mpox mortality ( OR:0.591, 95% CI:0.432-0.791) was the hindering factor for Mpox awareness.