Search

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 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.

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.

To investigate the changing patterns of respiratory viral infections within the context of COVID‐19 pandemic. The etiological surveillance data of eight respiratory viral pathogens among patients with ARIs in Shanghai between 2013 and 2023 were analyzed to evaluate the dynamic patterns of respiratory viral infections in Shanghai compared to global other regions during pre‐pandemic (period 1), pandemic (period 2), and post‐pandemic (period 3) periods of COVID‐19. In Shanghai and various other global regions, there was a delay of 2‒4 months in the peak positive rate of IFV and a reverse seasonality for RSV, HMPV, and HBoV was observed following the relaxation of NPIs. The proportion of patients infected with any of these eight viruses experiencing fever or high fever notably increased. During the entire study period, IFV was consistently identified as the most prevalent virus, with IFV‐B as the predominant stain during period 2, and IFV‐A regained its dominance following the lifting of NPIs. The proportion of RSV among children significantly increased during period 2 compared to period 1. With the relaxation of NPIs, there has been a resurgence of certain viral pathogens, accompanied by notable alterations in seasonal patterns and the spectrum of viral pathogens. [ABSTRACT FROM AUTHOR]

We aimed to understand the temporal dynamics of SARS‐CoV‐2 reinfection risk and assess the impact of inactivated vaccination on the occurrence of reinfection. We investigated the reinfection risk of SARS‐CoV‐2 from November 1, 2022, to February 12, 2023, when China rapidly lifted the zero‐COVID policy. The study subjects were those who were first infected during the zero‐COVID period between January 1, 2020, and October 31, 2022, in Dalian city, China. Among the 1961 previous infections, 126 (6.4%, 95% CI: 5.4, 7.5) were reinfected. The risk of reinfection increased over time since initial infection. Compared with those who did not receive or received one dose of inactivated vaccine, receiving two or three doses was associated with additional protection against reinfection among individuals who were infected with pre‐Omicron more than a year earlier, with the OR ranged from 0.33 (95% CI: 0.03, 1.83) to 0.91 (95% CI: 0.22, 3.27). In contrast, no protective effect from two or three doses of vaccines against reinfection was observed among those who were first infected with Omicron variants within a year. Primary or booster vaccination contributed to limited protection against reinfection or symptomatic reinfection among individuals infected with Omicron SARS‐CoV‐2 within a year. However, a booster dose after 1 year of natural infection may provide additional protection against reinfection. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the level of inactivated A71 (EV-A71) vaccination in Pudong New Area of Shanghai and its effects on the epidemiology and pathogen spectrum of hand–foot–mouth disease (HFMD) in this area, as well as to provide a basis for improving the prevention and control strategy of HFMD in this area. Data were collected from the "Comprehensive Management Cloud Platform for Immunization Program" system from December 2016 to December 2022. The data on HFMD cases from January 2012 to December 2022 were extracted from the "China Information System for Disease Control and Prevention". A total of 484,056 doses were administered. The vaccination rate of the first dose was 14.03%, and the full vaccination rate was 13.33%. There were significant differences between the first dose and the full vaccination rate in different years (χ2 = 46,538.831, p < 0.001, χ2 = 50,013.946, p < 0.001). A total of 91625 cases of HFMD were reported, including 58 severe cases, and no deaths. Before and after the administration of the inactivated EV-A71 vaccine, there were statistical differences in the distribution of HFMD cases in terms of gender, household registration, occupation, and age (p < 0.001). The etiological surveillance results showed that the rate of enterovirus positivity was 84.15%, with 9.85% being EV-A71, 23.74% CV-A16, and 50.56% non-EV-A71 and non-CV-A16. The coverage rate of the inactivated EV-A71 vaccine in Pudong New Area was not high, and the incidence of HFMD showed a downward trend after the postmarketing of the vaccine. The majority of HFMD infections were non-EV-A71 and non-CV-A16, with CV-A6 accounting for the highest proportion. It is recommended to accelerate the development of combined vaccines to provide more antibody protection. [ABSTRACT FROM AUTHOR]

Background: The occurrence and dissemination of hypermucoviscous and hypervirulent Klebsiella pneumoniae (hm-hvKp) isolates in clinical settings are a critical public health problem in the world. However, the data on these isolates in community populations are limited. This study aims to understand the prevalence and molecular characteristics of hm-hvKp isolates in community patients in Shanghai, China. Methods: In 2018, an active surveillance system focused on hm-hvKp in community diarrhoeal cases was implemented in Pudong New Area, Shanghai, China, involving 12 sentinel hospitals. The antimicrobial susceptibility of hm-hvKp isolates from fecal samples was tested, and whole-genome sequencing (WGS) was performed to predict the serotypes and sequence types and to identify antimicrobial resistance determinants, virulence determinants, and phylogenetic clusters. Results: The overall prevalence of hm K. pneumoniae isolates was 2.48% (31/1252), with the proportions of 1.76% (22/1252) for hm-hvKp and 0.72% (9/1252) for hm not hv K. pneumoniae. The prevalence of hm-hvKp isolates among different age groups and different months was statistically significant. All the 22 hm-hvKp isolates were susceptible to 20 antimicrobial agents and only carried blaSHV gene, and KL1 and KL2 accounted for eight (36.36%) cases and seven (31.82%) cases, respectively. The eight ST23/KL1 isolates belonged to the predominant CG23-I clade, which typically possessed the virulence determinants profile of rmpA/rmpA2-iro-iuc-ybt-irp-clb. The five ST86/KL2 isolates were assigned to the global clusters ST86/KL2-1 (n=2), ST86/KL2-2 (n=2), ST86/KL2-3 (n=1), all lack of the clb gene. Shanghai ST23/KL1 and ST86/KL2 isolates were closely related to the global isolates from liver abscesses, blood, and urine. Conclusion: Hm-hvKp is carried by the community population of Shanghai, with ST23/KL1 and ST86/KL2 isolates predominant. Hm-hvKp isolates of different continents, different sources, and different virulence levels were closely related. Ongoing surveillance of hm-hvKp isolates in the community population is warranted. [ABSTRACT FROM AUTHOR]

Norovirus is the most common cause of gastroenteritis (i.e., diarrhea or vomiting) (1). Diarrhea represents the second greatest burden of infectious disease in the world, and globally, [approximately equal to] [...]

International travel may facilitate the spread of the novel coronavirus disease (COVID‐19). The study describes clusters of COVID‐19 cases within Chinese tour groups travelling in Europe January 16–28. We compared characteristics of cases and non‐cases to determine transmission dynamics. The index case travelled from Wuhan, China, to Europe on 16 January 2020, and to Shanghai, China, on 27 January 2020, within a tour group (group A). Tour groups with the same outbound flight (group B) or the same tourism venue (group D) and all Chinese passengers on the inbound flight (group C) were investigated. The outbreak involved 11 confirmed cases, 10 suspected cases and six tourists who remained healthy. Group A, involving seven confirmed cases and six suspected cases, consisted of familial transmission followed by propagative transmission. There was less pathogenicity with propagative transmission than with familial transmission. Disease was transmitted in shared outbound flights, shopping venues within Europe and inbound flight back to China. The novel coronavirus caused clustered cases of COVID‐19 in tour groups. When tourism and travel opens up, governments will need to improve screening at airports and consider increased surveillance of tour groups—particularly those with older tour members. [ABSTRACT FROM AUTHOR]