ObjectiveTo present the exploration and application of a prospective follow-up research method for acute infectious disease surveillance based on natural community populations， using COVID-19 infection as an example， and to provide a reference for improving the infectious disease surveillance and early warning system. MethodsA multi-stage probability proportional sampling method was employed to sample residents from all communities of 16 administrative districts in Shanghai， with households as the units. A cohort for acute infectious diseases based on natural community populations was established. The baseline survey was conducted for all cohort subjects， and COVID-19 antigen test kits were distributed. From December 21， 2022 to September 30， 2023， prospective follow-up monitoring of COVID-19 antigen and nucleic acid was carried out on the study subjects on a weekly basis. The baseline characteristics and follow-up information of the cohort subjects were described. ResultsThe cohort for acute infectious diseases included a total of 12 881 subjects， comprising 6 098 males （47.3%） and 6 783 females （52.7%）. The baseline survey revealed that 35.2% （4 540/12 881） of the subjects had a history of COVID-19 infection. During the follow-up period from December 21， 2022 to September 30， 2023， the average incidence density in the cohort was 0.61/person-year， with a higher incidence density in females （0.63/person-year） compared to males （0.59/person-year）. Individuals aged 60 and above （0.64/person-year） and those with underlying health conditions （0.67/person-year） had a higher incidence density. Healthcare workers showed a notably higher incidence density （0.84/person-year） than that in other occupational groups. As of September 30， 2023， a total of 340 subjects in the cohort experienced secondary infections， with a median interval of 170 days between the first and second infections. ConclusionThis study applies cohort study method to acute infectious disease surveillance， providing crucial data support for estimating infection rates and forecasting alerts for acute infectious diseases in the community. This method can be promoted and applied as a new approach for acute infectious disease surveillance.

Objective:To analyze the growth characteristics of different genotypes of Japanese encephalitis virus (JEV) in different cell lines, and to provide scientific basis for the selection of cell lines in the study of JEV.Methods:BHK-21, Vero, C6/36, PK-15, DF-1, N2a, SH-sy5y and MDCK cell lines were selected. The proliferation ability of genotype 1 (NX1889 strain), genotype 3 (P3 strain) and genotype 5 (XZ0934 strain) JEV in these cell lines was evaluated by plaque assay and RT-qPCR.Results:Significant cytopathogenic effects (CPE) were observed in BHK-21, Vero, C6/36, DF-1, N2a and PK-15 cell lines across all three JEV genotypes. However, no significant differences in CPE characteristics were observed within the same cell line. SH-sy5y and MDCK cell lines did not show significant CPE, but virus proliferation was detected in SH-sy5y cell line, while MDCK cell line were found to be insensitive to JEV. No significant difference was observed in the proliferation curves of G1, G3 and G5 JEV in BHK-21, Vero and SH-sy5y cell lines. In C6/36 and PK-15 cell lines, the titer of G1 JEV was higher than that of G3 and G5. In DF-1 cell line, G5 demonstrated a higher titer than the other two genotypes, whereas in N2a cell line, G5 showed a lower titer than the other two.Conclusions:There are differences in the proliferation of three different genotypes of JEV in different cell lines, which can provide reference for the study of JEV in different directions.

Objective:To elucidate the etiological and epidemiological characteristics and epidemiological patterns of viral acute respiratory infections (ARI) in Shanghai during 2023, with the aim of providing robust laboratory evidence for effective prevention and control strategies against related respiratory diseases and facilitating risk assessment.Methods:Respiratory pathogens were detected in the clinical surveillance specimens submitted by sentinel hospitals through multiplex PCR, as part of the multi-pathogen surveillance of acute respiratory infections in Shanghai during 2023. The obtained detection result were statistically analyzed in conjunction with sample information.Results:The positive detection rate of viral pathogens in 2023 was 21.17% (984/4 648), with rates of 33.53% (504/1 503) observed in ILI cases and 15.62% (480/3 145) in SARI cases. Influenza A virus (FluA) was the predominant virus detected, accounting for 13.7% (637/4 648). Other viruses identified in the surveillance samples included influenza B virus (Flu B), human rhinovirus/enterovirus (HRV/HEV), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), parainfluenza virus (PIV), adenovirus (ADV) and human bocavirus (HBoV). Regarding temporal distribution, HRV/HEV and RSV exhibited the highest detection rates during the second quarter at 2.27% each (28/1 236). PIV had its peak during the third quarter at a rate of 2.49% (35/1 405), and HMPV showed prevalence mainly during the third and fourth quarters, with detection rates of 2.63% (37/1 405) and 2.35% (32/1 360), respectively.Conclusions:In acute respiratory infection surveillance cases in Shanghai in 2023, Flu A emerged as the predominant respiratory pathogen. The detection rate of HMPV ranked second only to Flu A, while other respiratory viruses such as HRV/HEV, RSV, and PIV were detected during different seasons and co-circulated. The prevalence of various respiratory viruses varied among different infected populations and over times.

Objective:To investigate the correlation between cardiac polyps and gastroesophageal flap valve (GEFV).Methods:The clinical, endoscopic and pathological data of 349 patients with cardiac polyps (the cardiac polyp group) visiting Affiliated Hospital of Yangzhou University from January 1, 2016 to December 31, 2021 were retrospectively collected, and the same number of non-cardiac polyp patients (the non-cardiac polyp group) were matched in the same period as control according to the propensity score. The clinical, endoscopic and pathological data of the two groups were compared.Results:After matching with propensity score, there were 296 patients in each group, with no significant differences in smoking, acid reflux, heartburn, Helicobacter pylori infection, bile reflux, reflux esophagitis or pancreatitis between the two groups ( P>0.05). Compared with the non-cardiac polyp group, the risk of cardiac polyps increased in GEFV Ⅱ patients ( OR=3.046, 95%CI: 2.100-4.419, P<0.001) and GEFV Ⅲ patients ( OR=4.202, 95%CI: 2.299-7.681, P<0.001). Compared with the non-cardiac polyp group, the risk of cardiac polyps increased in patients with GEFV abnormalities ( OR=2.822, 95%CI: 1.615-4.931, P<0.001). GEFV abnormalities was associated with the cardiac polyp site ( χ2=22.169, P=0.003) and was not significantly associated with cardiac polyp size, number, morphology, intestinal metaplasia of the surrounding mucosa or intraepithelial neoplasia ( P>0.05). Conclusion:The occurrence of cardiac polyps is related to GEFV, and the patients with GEFV abnormalities are more likely to develop cardiac polyps.

Objective:To explore the efficacy and safety of endoscopic radial incision (ERI) for congenital membranous duodenal stenosis (MDS).Methods:The clinical data of 13 children with MDS receiving ERI in the Department of Gastroenterology of Xi'an Children's Hospital from May 2017 to December 2021 were reviewed and analyzed. The perioperative management, surgical procedures, postoperative complications and follow-up were summarized.Results:There were 5 boys and 8 girls with a median disease duration of 8 (2-20) months, and the median age of diagnosis was 13 months (5-30 months). The septum of 10 cases (10/13) was located in the descending part of the duodenum, and that of 3 cases (3/13) in the horizontal part. The papilla of 1 case (1/13) opened on the septum, that of 3 cases (3/13) within 5 cm of the mouth side of the septum, and that of 9 cases (9/13) within 5 cm of the anal side of the septum. The median diameter of the septal aperture was 3 mm (2-6 mm). All 13 children successfully underwent ERI with a median operation time of 20 min (15-32 min). The average surgical incision was 3 strokes (2-4 strokes), and the endoscope with outer diameter 9.9 mm could pass stenosis after ERI. The median incision diameter was 10 mm (10-12 mm). All patients achieved relief of clinical symptoms after ERI. One patient (1/13) suffered from the postoperative delayed bleeding, which was stopped by endoscopic titanium clamping. No intestinal perforation or duodenal papilla injury occurred, and median postoperative hospital stay was 6 days (5-10 days). The upper gastrointestinal angiogram and gastroscopy were repeated 3 months after ERI, and the median diameter of stenosis was 12 mm (10-15 mm), which was significantly dilated compared with before. The mean body weight increase at 1 month after ERI was 1.20 kg (0.50-1.80 kg), and the mean body weight increase at 3 months was 3.50 kg (2.50-4.00 kg), which reached the normal body weight of the same age.Conclusion:ERI is safe and effective for the treatment of MDS in children, and shows good clinical application and promotion value.

Objective Summarizes the current research status of defensive medicine in China and provides references for future research.Methods The search period spans from the inception of the database to March 2024.CNKI,Wan-fang Data,Web of Science,PubMed databases were queried,followed by literature screening based on predeter-mined inclusion and exclusion criteria.The current landscape of defensive medicine research in China was synthe-sized and categorized based on fundamental research characteristics,measurement methodologies,influencing fac-tors,and other relevant aspects.Results A total of 24 Chinese literature sources and 4 foreign literature sources were incorporated,indicating a prevalent occurrence of defensive medicine in China.Measurement tools for defen-sive medicine exhibit variability across different studies.Key influencing factors encompass doctor's demographic vari-ables such as gender,age,and professional status,institutional factors like legal frameworks and medical in-surance,and sociol-cultural factors such as doctor-patient relationships and adverse public perceptions.Conclusion Defensive medicine is relatively widespread and influenced by various factors in China.It's urgent to explore the for-mation mechanism of defensive medicine from multiple perspectives and provide evidence for passive defen-sive medicine governance.

Objective To clarify the influencing factors of defensive medicine and provide ideas for preventing and re-solving defensive medicine.Methods Literature related to defensive medicine was searched,personnel related to de-fensive medicine were interviewed,and literature and interview data were coded with the method of grounded theo-ry,and related concepts and categories were summarized.Results After three levels of coding,52 initial concepts,23 initial categories,7 sub-categories and 3 main categories were sorted out,and the correlation among influencing factors was analyzed to build a three-dimensional model of"doctor-patient relationship-institutional system-social environment"influencing factors and their mechanism of action.Conclusion The influencing factors of defensive medi-cine mainly include doctor-patient relationship,institutional system and social environment.The three factors have an impact on defensive medicine through different mechanisms of action,which provides qualitative evidence for comprehensive analysis of factors in related studies of defensive medicine.

Objective By exploring the conditional configuration effect of negative defensive medicine behavior,the formation mechanism and causal path of negative defensive medicine are explained,and systematic suggestions are provided for negative defensive medicine behavior,so as to improve the rational utilization of health resources.Methods NCA and fsQCA are used to conduct configuration analysis on factors influencing passive defensive medical behavior,output the conditional configuration,and further analyze the configuration effects among the influencing factors.Results The antecedent conditions of negative defensive medicine include systemic mechanisms,institutional norms,social culture,doctor-patient relationships,and self-efficacy.Ultimately,two paths contributing to passive defensive medical behavior emerge:environment conduction type and efficiency-environment joint conduction type,their consistency is 0.830.Conclusion To reduce the negative defensive medical behavior,it should pay atten-tion to improving the institutional environment and improving doctors'self-efficacy,establish a fair and reasonable external institutional environment,create an honest and harmonious cultural atmosphere,strengthen the training of doctors'professional ability and improve the doctor-patient relationship,so as to improve the rational use of health resources.

Objective To understand the status of behavioral intentions of defensive medical treatment in medical students,and explore the relationship between practice environment and behavioral intentions of defensive medical treatment.To provide reference for reducing the tendency of defensive medicine(DM)behavior of medical students and improving the negative effects of DM.Methods A web-based questionnaire survey was conducted among medi-cal students in four medical colleges in Heilongjiang Province.The structural equation modeling of the relationship be-tween practice environment and behavioral intentions of defensive medical treatment in medical students was con-structed by Amos 26.0 software.Results The mean score of medical students'behavioral intentions of positive and negarive defensive medical treatment was 44.49-6.90 and 20.06-6.83,respectively.The behavioral intention of posi-tively defensive medical treatment was positively associated(β=0.892,P＜0.05)with cognition of doctor-patient relationship.While the behavioral intention of negative defensive medical treatment was positively correlated(β=0.403,0.343,P＜0.05)with environment cognition,perception of risk and negatively correlated(β=-0.726,P＜0.05)with cognition of doctor-patient relationship.As an intermediary variable,the direct and indirect effects of cog-nition of doctor-patient relationship on negative defensive medical behavior tendency were-0.470 and 0.043,the difference was statistically significant(P＜0.05).Conclusion Improving cognition of medical students'doctor-pa-tient relationship is beneficial to understand defensive medical treatment for medical students.The negative defen-sive medical behavior tendency of medical students should be reduced by reducing their negative cognition of environ-ment or improving their cognition of doctor-patient relationship.

Objective Summarizes the current research status of defensive medicine in China and provides references for future research.Methods The search period spans from the inception of the database to March 2024.CNKI,Wan-fang Data,Web of Science,PubMed databases were queried,followed by literature screening based on predeter-mined inclusion and exclusion criteria.The current landscape of defensive medicine research in China was synthe-sized and categorized based on fundamental research characteristics,measurement methodologies,influencing fac-tors,and other relevant aspects.Results A total of 24 Chinese literature sources and 4 foreign literature sources were incorporated,indicating a prevalent occurrence of defensive medicine in China.Measurement tools for defen-sive medicine exhibit variability across different studies.Key influencing factors encompass doctor's demographic vari-ables such as gender,age,and professional status,institutional factors like legal frameworks and medical in-surance,and sociol-cultural factors such as doctor-patient relationships and adverse public perceptions.Conclusion Defensive medicine is relatively widespread and influenced by various factors in China.It's urgent to explore the for-mation mechanism of defensive medicine from multiple perspectives and provide evidence for passive defen-sive medicine governance.