ObjectiveTo obtain the epidemiological characteristics of re-positive cases infected with SARS-CoV-2 in Pudong New Area from March to July 2022, including clinical manifestations, duration of a negative nucleic acid conversion after tested for re-positive, and length of time from the discharge of the initial infection to the most recent re-positivity, so as to provide a scientific basis for the prevention and control of COVID-19. MethodsA questionnaire survey was conducted among the re-positive cases infected with SARS-CoV-2 after discharged from hospital/quarantine facility in Pudong New Area, and descriptive epidemiological methods were used for characteristics analysis. ResultsA total of 2 422 re-positive cases met the inclusive and exclusive criteria, with males accounting for 61.02%. The age distribution mainly fell between 18 and <60 years old, accounting for 62.39%. Clinical manifestations were predominantly asymptomatic (72.15%), followed by cough (12.03%) and sore throat (6.58%). Among the stratified randomized sample of 416 individuals, there were statistically significant differences in symptoms (χ²=262.667, P<0.001), clinical typing (χ²=12.996, P=0.001), and duration of a negative nucleic acid conversion (χ²=142.578, P<0.001) between the initial positive and re-positive instances. Besides, statistically significant differences in symptoms (χ²=13.696, P=0.016) and self-perception of the severity of re-infection (χ²=7.923, P=0.048) between the initial and re-positive cases were observed by different genders. ConclusionAmong re-positive cases, males experienced milder symptoms compared to females, and the self-perception of symptoms during re-positivity is milder than that in the initial positive infection. The length of time for negative nucleic acid conversion during the initial positive period is shorter than that during the re-positive period.

ObjectiveTo investigate the infection characteristics of respiratory syncytial virus (RSV) in children with acute respiratory tract infection (ARI) in Pudong New Area, Shanghai, from 2013 to 2023, so as to provide an evidence for the prevention and control of RSV in Shanghai. MethodsChildren who sought medical care at sentinel healthcare facilities in Pudong New Area, Shanghai, between January 2013 and December 2023 and met the case definition of ARI were included in the study. Nasopharyngeal swab samples were collected and tested for viral pathogens using real-time fluorescene PCR, and the clinical information of whom was collected simultaneously. ResultsA total of 4 980 children were included in the ARI surveillance, among whom 231 tested positive for RSV, with an overall detection rate of 4.64%. Of these, 106 cases were type A and 125 were type B. From 2013 to 2023, the detection rate of RSV in children showed an overall trend of initial increase followed by a decline, with higher detection rates in autumn and winter and lower rates in spring and summer. The RSV detection rate gradually decreased with age, with the highest rate observed in children <1 year old, accounting for 16.33% (80/490) of RSV-detection cases. Cough was the most common clinical symptom. Among the RSV-positive cases, 36 involved co-infection with another virus, 6 co-infected with three viruses, and 1 with mixed infection of four viruses. The most frequent co-infection was RSV and human coronavirus. ConclusionChildren under 1 year of age are more susceptible to RSV infection, with cough being the predominant symptom. RSV infection in Pudong New Area, Shanghai, mainly occurs in winter. Targeted prevention and control measures should be taken for children under 1 year old during the winter season to reduce the risk of both RSV infection and co-infection with human coronavirus and influenza virus.

Objective To understand the viral spectrum of inpatients with acute respiratory infection in Pudong New Area, and to explore the composition of pathogens in hospitalized children and adults. Methods Samples of acute respiratory infection cases from 10 medical institutions were collected from 2011 to 2020 and tested for human influenza virus, human adenovirus, rhinovirus, human parainfluenza virus, respiratory syncytial virus, human coronavirus, human metapneumovirus and human boca virus. Results A total of 3 145 inpatients were monitored, with a median age of 61 years. The positive rate of any virus was 32.43% (1 020/3 145), and the single virus infection accounted for 85.98% (877/1 020). In single virus infection, the positive rate of human influenza virus was the highest (9.67%, 304/3 145), with influenza A (80.26%, 244/304) as the main virus. The second was rhinovirus (3.97%, 125/3 145). The positive rate of any virus in different age groups was statistically significant (χ²=103.38，P<0.001). The positive rate of respiratory syncytial virus was the highest in the ~5-year-old group, adenovirus was the highest in the 6-14-year-old group, and influenza virus was the highest in the 15-64-year-old group and the 65year-old group. There was a significant difference in the positive rate of any virus in each month (χ²=123.06，P<0.001). The human influenza virus was the dominant virus in winter (December to February) and summer (July to September), and rhinoviruses distributed sporadically in each month. The positive rate of any virus in different departments was significantly different (χ²=90.37，P<0.001). Conclusion The positive rate of virus in hospitalized patients with acute respiratory infection is relatively high in Pudong New Area, Shanghai, with human influenza virus being the main virus. The virus spectrum of hospitalized children and adults is inconsistent. In the future, in-depth research should be strengthened, focusing on the distribution of pathogens in different populations and seasonal prevention and treatment.

ObjectiveTo identify the rate， population characteristics， and vaccination history of repeat infections among previously infected people in the current epidemic based on the rate of repeat infection and population characteristics of different mutant strains at different times in Pudong New Area of Shanghai， and to provide reference for the prevention and control strategies of novel coronavirus repeat infections. MethodsA total of 9 250 investigated subjects were randomly selected from the new cases of asymptomatic infection and confirmed cases reported by Pudong New Area from March to May 2022. The investigation mainly focused on demographic characteristics， nucleic acid or antigen test results， and symptoms after infection. The repeat infection rates among different populations were compared， and logistic regression was used to analyze the impact of gender， age， and vaccination status on repeat infections. ResultsThe survey sample of 9 250 people had a response rate of 81.85%. There were 4 043 males （53.40%） and 3 528 females （46.60%）， with a median age of 34 years old （P₂₅， P₇₅： 7， 61）. The overall vaccine uptake rate was 59.44% （4 500/7 571）. In December of 2022， there were 563 cases of repeat infection， with an infection rate of 7.44%. The lowest rate of repeat infection was seen in the 3‒ year-old group （2.86%） and the highest rate in the 30‒ year-old group （12.42%）， with significant differences between different age groups. The repeated infection rate for those who had completed their vaccinations was significantly lower （6.57%） compared to those who had not （7.11%）. The age groups of 3‒ years， 70‒79 years， as well as individuals who completed full vaccination and received booster shots were protective factors against repeat infections. ConclusionThe overall rate of reinfection among the infected in Shanghai during the spring of 2022 was low in the outbreak of the Omicron variant， and the rate of reinfection in the 3‒ year-old group was significantly lower than in other age groups. Completing the full course of vaccination significantly reduces the risk of reinfection. Although the reinfection rate is high in individuals who received booster shots， it remains a mitigating factor compared to those who do not receive the vaccine. It is recommended to continue monitoring reinfections in key populations and further strengthen immunization efforts.

ObjectiveTo analyze the epidemiological characteristics and etiology of clustered outbreaks of hand， foot， and mouth disease （HFMD） in Pudong New Area， Shanghai from 2017 to 2022， and to provide a scientific basis for the prevention and control of HFMD in the area. MethodsThe data related to HFMD clustered outbreaks from 2017 to 2022 were obtained from the Pudong New Area HFMD outbreak database. Descriptive analysis was conducted to explore the outbreak scope， seasonal characteristics， distribution of occurrence settings， and etiological composition. ResultsFrom 2017 to 2022， Pudong New Area reported a total of 2 547 HFMD clusters， involving 8 884 cases， with an average of 3.49 cases per event. The majority of events （78.52%） had between 2 and 4 cases. The peak reporting periods for clustered HFMD from 2017 to 2019 and in 2021 were during the summer （May‒July） and autumn （September‒November）. The seasonal pattern was less distinct in 2020 and 2022， likely due to the impact of the COVID-19 pandemic. The majority of clustered outbreaks occurred in childcare facilities （44.64%）， followed by households/neighborhood committees （44.21%）， with schools accounting for a smaller proportion （12.39%）. The etiology revealed the coexistence of multiple enterovirus genotypes， with a positive detection rate of 60.46%， and CoxA6 being the dominant strain. ConclusionHFMD clustered outbreaks in Pudong New Area show fluctuating trends， with significant yearly differences in the number of incidents. The predominant seasons for outbreaks are summer and autumn， with CoxA6 identified as the dominant strain. The implementation of prevention and control measures for COVID-19 significantly reduced the occurrence of HFMD outbreaks. Continuous monitoring and focus on large-scale clustered outbreaks in key institutions are essential for the future.

Objective:To establish an indicator system for surveillance of data sources to provide a theoretical basis for respiratory infectious disease surveillance and early warning.Methods:Indicators for data sources in the surveillance of acute respiratory infectious diseases were initially compiled through a literature search. Subsequently, two rounds of expert consultations were conducted with 22 experts using the Delphi method to refine the indicators.Results:The questionnaire recovery rates for the two rounds of expert consultation were 100.00% and 86.36%, respectively. The authority coefficient of the experts was 0.83. The coordination coefficient of the second round of Delphi expert consultation was 0.32, and the coefficient of variation of each indicator was less than 0.25. Finally, the indicators system of data source for the surveillance of acute respiratory infectious diseases includes 4 first-level indicators, 10 second-level indicators, and 26 third-level indicators.Conclusion:The indicator system of data sources for the surveillance of acute respiratory infectious diseases constructed in this study is reasonable and reliable, providing a valuable reference for surveillance, early warning and policy formulation of acute respiratory infectious diseases.

ObjectiveTo understand the epidemiological characteristics of recovered COVID-19 cases with re-positive nucleic acid in Pudong New Area of Shanghai, and to provide a reference for the prevention and control of COVID-19. MethodsA three-month health follow-up and nucleic acid testing were conducted on 339 COVID-19 cases cured and discharged between May 20 and June 20, 2022, in Pudong New Area, Shanghai, to analyze their epidemiological characteristics. ResultsAmong the 339 follow-up cases, 75 cases experienced re-positive nucleic acid results, with a recurrence rate of 22.12%. Factors such as gender, age group, occupation, presence of heart disease, hypertension, and full vaccination status had no effect on the re-positive results. Being diagnosed as a confirmed case during the first presence of infection, having diabetes, and a hospitalization period of ≤7 days were related factors for recurrence. The median interval between discharge and re-positive nucleic acid results was 26 days. The close contacts of the re-positive cases did not contract COVID-19 after the isolation and observation period. ConclusionThere is a possibility of re-positive nucleic acid results after COVID-19 recovery and discharge. Cases initially diagnosed as confirmed cases and those with a hospitalization period of no more than 7 days have a high rate of re-positivity. No secondary transmission is observed from the re-positive cases.

ObjectiveTo explore the incidence, characteristics, and influencing factors of non-suicidal self-injury behavior (NSSI) in adolescent patients with mental disorders in Wenzhou City, and to provide a basis for proposing effective preventive intervention strategies. MethodsA total of 500 adolescent patients with mental disorders admitted to the Seventh People’s Hospital of Wenzhou City from June 2022 to June 2023 were selected as the research subjects. Based on the definitions in the Third Edition of the Chinese Classification Scheme and Diagnostic Standards for Mental Disorders (CCMD-3), whether the patients had experienced NSSI within the past year was evaluated. Patients were divided into two groups based on the presence of NSSI: the occurrence group and the non-occurrence group. A logistic regression model was used to analyze the influencing factors of NSSI in adolescent patients with mental disorders. ResultsAmong the 500 adolescent patients with mental disorders, the incidence of NSSI was 39.40%. Among the adolescent patients with mental disorders who experienced NSSI, the main areas of self-injury were the forearm and wrist, hand, accounting for 36.54% and 23.86%, respectively. The main methods of self-injury were cutting and collision, accounting for 50.25% and 29.44%, respectively. Childhood family dysfunction, academic pressure, childhood abuse experiences, campus violence, mother’s education level, and Loneliness Scale (LRS) scores were related factors for the occurrence of NSSI in adolescent patients with mental disorders, and the differences were statistically significant (P<0.05). Multivariate logistic regression analysis showed that having a mother with a junior college education or above, experiencing campus violence, childhood abuse experiences, childhood family dysfunction, high academic pressure and an LRS score >11 points were risk factors for NSSI in adolescent patients with mental disorders (all P<0.05). ConclusionThe occurrence of NSSI in adolescent patients with mental disorders is closely related to factors such as having a mother with a junior college education or above, high academic pressure, exposure to campus violence, childhood abuse experiences, childhood family dysfunction, and an LRS score >11 points.

Objective To understand the seasonal and etiological characteristics of the epidemic situation of cluster fever in Pudong New Area, Shanghai, and to provide a scientific basis for the formulation of prevention and control strategies. Methods The epidemic data of cluster fever in Pudong New Area of Shanghai from 2013 to 2021 were collected, and the data were analyzed by concentration degree and circular distribution methods. Results From 2013 to 2021, there were 109 cases of cluster fever reported in Pudong New Area, with primary schools reporting the most cases, 77 cases (70.64%). The M value was 0.59. Circular distribution results showed that angle dispersion index r value was 0.54, the average angle was 357.32^°, and the average angle of Rayleigh’s test Z value was 32.07. The peak day was December 28, and the peak period was from October 25 to March 3 of the following year. The cluster of fever in Pudong New Area was mainly caused by influenza virus. Most cases were single pathogen infection, and some were double pathogen infection. Influenza A virus had the highest detection rate in both single pathogen infection and double pathogen infection. Conclusion Primary schools are the focus of prevention and control of the cluster of fever in Pudong New Area. The epidemic situation of cluster fever has a strong seasonal characteristic, and the peak of incidence is from late October to early March of the next year. Respiratory pathogens such as influenza virus are the main causes of the epidemic situation.

Objective To understand the epidemiological characteristics of norovirus infectious diarrhea in Pudong New Area of Shanghai, and to provide reference for prevention and control of diarrhea caused by norovirus. Methods Epidemiological data and stool samples from diarrhea cases of 15 hospitals in 2015-2019 years were collected. The two subtypes of norovirus G I and G II were detected by RT-PCR and analyzed. Results A total of 9 397 diarrhea samples were collected in 2015-2019 years, and 1 938 positive norovirus samples were detected, with a positive rate of 20.62%. The majority of serotypes were GII (88.60%). Diarrhea caused by norovirus occurs all year round, with high incidence season in 2-3and 10-12 months every year. There was no significant difference in the positive rate of norovirus between different sexes（χ²=2.611，P=0.106）. The positive rate of the 15-64 year old group was higher than that of the 0-14 year old group and the 65 year old and above group（χ²=153.634，P<0.001）. The highest positive rate was for cadres /worker/ business services / teachers / medical staff / drivers. The positive rate of norovirus in diarrhea cases with vomiting was significantly higher than that in patients without vomiting. Conclusions Diarrhea caused by norovirus is related to season, age and occupation. Because there is no effective antiviral drugs and vaccine prevention, continuous monitoring should be carried out and targeted preventive measures should be carried out according to epidemiological characteristics.