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ObjectiveTo investigate the changes in the pathogen spectrum of viral diarrhea in local pediatric inpatients as well as any variations in genotypes of major pathogens during the COVID-19 control period.MethodsFecal samples were collected from the children

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.

ObjectiveTo investigate an outbreak of norovirus diarrhea in a welfare home for the elderly in Shanghai， and to analyze the epidemiology and virus genotype characteristics of the epidemic， thus providing a scientific basis for the prevention and control of norovirus epidemic.MethodsCase definition was clarified. After case definition， a standardized questionnaire was used to carry out case investigation to make comprehensive analysis in combination with field epidemiological investigation and laboratory tests results.ResultsThe epidemic lasted for 14 days， and 23 cases were reported with an incidence rate of 12.37% （23/186）， including 3 males and 20 females. There were more cases on the 1st， 4th and 6th floor of the main building in the welfare home， accounting for 52.17% （12/23） of total cases. 19 cases were reported in the main building， with an incidence rate of 11.59% （19/164）； 4 cases were reported in the auxiliary building， with an incidence rate of 18.18% （4/22）. There was no significant difference in the morbidity between the main building and the auxiliary building （χ2=0.779，P>0.05）. The main clinical manifestations were vomiting and diarrhea. There was a significant difference in the incidence of vomiting symptoms among the elderly， nursing staff and other staff in the welfare home （χ2=10.216， P0.05）. Fecal samples were collected from 23 cases， 1 case family member， 68 risk personnel and 14 environmental surface swab samples. Norovirus GⅡ was detected in stool samples of 19 cases， 1 family member and 36 risk personnel.ConclusionOutbreak of norovirus infection is reported in a welfare home in Shanghai. The close contact between the elderly and health workers might lead to the outbreak.

Hot cracking is a frequent and severe defect that occurs during laser additive manufacturing of superalloys. In this work, a pulsed-wave (PW) laser modulation process was employed to control the solidification microstructure and reduce the hot cracking susceptibility of laser additive manufactured cobalt-based superalloy. The effects of continuous-wave (CW) and PW laser processing modes on the dendrite morphology, element segregation, eutectic phase, and hot cracking of fabricated Co-based superalloys were investigated. Optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize the microstructural characteristics of samples. A two-color pyrometer was used to measure the molten pool temperature variation under different laser processing modes. The results show that coarse columnar dendrites, chain-like eutectic carbides, and hot cracks were observed in the CW sample. In contrast, the fine equiaxed crystals, discrete eutectic carbides, and low-level residual stresses were obtained to avoid hot cracks, owing to the high cooling rate and the periodic melting and solidification of the molten pool under the PW laser processing mode. This work provides a new method for controlling solidification structure and hot cracking of laser additive manufactured Co-based superalloy. [ABSTRACT FROM AUTHOR]

In order to meet the needs of prevention and control of intestinal infectious diseases， a comprehensive surveillance for diarrheal diseases has been innovated and explored in Shanghai since 2012. The surveillance has extensive distribution of sentinel hospitals， systematic sampling， multi-pathogen collection， and hospital information system （HIS） as the basis， which has achieved “One system for surveillance of multiple diseases and one sample for detection of multiple pathogens". Continual active surveillance for the whole population has been conducted， covering demography， clinical information， epidemiology， pathogen detection， and drug sensitivity test for diarrhea cases. The surveillance has obtained preliminary achievements as follows. First， diarrheal diseases and their periodic changes have been characterized， in which the most prevalent pathogen of diarrhea is determined to be norovirus in Shanghai. Second， some rare pathogens and serotypes have been identified that may provide clues to the sources of outbreaks. Third， it facilitates the information sharing between public health institutions and clinical institutions， and provides scientific evidence for clinical diagnosis and treatment. In the future， Shanghai diarrhea comprehensive surveillance will be improved for expanding range and depth of surveillance， artificial intelligence assisted diagnosis and treatment， early warning of outbreaks， prediction of epidemic trends， and application of new detection technologies.

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]

Polymerization dynamics of single actin filaments coupled with adenosine triphosphate (ATP) hydrolysis is investigated via both theoretical analysis and Brownian dynamics simulations. Brownian dynamics simulations have been applied recently to study the growth behaviors of long filaments as a function of the free actin monomer concentrations, CT, which is found to be in agreement with the associated experiments. In the present study, both ATP cap length and length diffusivity are studied as a function of the free ATP-actin monomer concentrations, CT. The exact analytical expressions are found to be in perfect consistency with Brownian dynamics simulations. Likewise, we find that the length diffusion coefficient is peaked near the critical concentration, CT, cr. It is, therefore, expected that the dependence of length diffusivity on ATP-actin monomer concentrations is utilized to analyze the surprising experiments on the length fluctuations of individual actin filaments. [ABSTRACT FROM AUTHOR]

It is well known that surface roughness always enhances wetting for hydrophilic, but drying for hydrophobic surfaces. In this letter, the authors found that La0.7Sr0.3MnO3 coatings display distinct wettability from superhydrophilicity to superhydrophobictiy, which is tuned by their hierarchical microstructures obtained by annealing the coatings composed of nanopowder at different temperatures. This offers a strong support to Herminghaus’s model [Europhys. Lett. 52, 165 (2000)] which predicts that the material hierarchical structure determines its wettability and widens the range of raw materials for superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

What Is Already Known About This Topic?: Foodborne diseases are a growing public health concern with a notable disease burden in China., What Is Added by This Report?: Two children with diarrhea visited a healthcare facility within 24 hours on August 1 and 2, 2023. Salmonella Grumpensis was detected in their stool samples by the public health laboratory. Whole genome sequencing (WGS) analysis revealed characteristics typical of outbreak strains. Although the origin of the outbreak was unknown, the possibility of a hidden shared infection was deemed feasible., What Are the Implications for Public Health Practice?: It underscores the importance of thorough genomic surveillance to promptly detect emerging pathogens. Public health laboratories play a crucial role by utilizing advanced genomic technologies for accurate pathogen identification and timely warning systems., Competing Interests: No conflicts of interest., (Copyright and License information: Editorial Office of CCDCW, Chinese Center for Disease Control and Prevention 2024.)

Objective: To understand the epidemiologic characteristics of confirmed and suspected norovirus outbreaks in Shanghai during 2010-2014., Methods: The investigation reports of confirmed and suspected norovirus outbreaks in Shanghai from 2010 to 2014 were analyzed., Results: A total of 80 norovirus outbreaks, involving 2 399 cases, were reported during this period, and the overall attack rate was 4.17%. The median of the outbreak duration was 4.5 days and the incidence peaked 2 days later averagely for an outbreak. The outbreaks mainly occurred in autumn and winter, 53 outbreaks occurred during October-February, accounting for 66.25%. Seventy five outbreaks occurred in schools, child care settings and nursing houses, accounting for 93.75%. The attack rates in hospitalized patients and the elders in nursing houses were higher than those in pre-school and school aged children, the differences were statistically significant (χ² =683.12, P<0.01). The attack rates in medical staff and nurses in hospitals and nursing houses or staff in pre-schools and schools were lower. Vomiting, the main clinical symptom, occurred in 1 900 cases (79.20%), diarrhea and fever developed in 694 cases (28.93% ) and 364 cases (15.17% ) respectively. The differences were statistically significant (χ² =2 251.48, P<0.01). The outbreaks were mainly caused by short common exposures and contact with cases., Conclusion: The surveillance for norovirus infection should be strengthened in hospitals, schools and others with the crowed during autumn-winter. The protection of risk population should be enhanced.

Objective: To study the epidemiological characteristics and antibiotic resistance of Salmonella enterica serovar Pomona (S. Pomona)., Methods: Antimicrobial susceptible testing (AST) and pulsed field gel electrophoresis (PFGE) methods were used to analyze on S. Pomona strains that were isolated from diarrhea cases through the diarrhea network monitoring program, environment and food samples in Shanghai as well as from reptiles in Guangxi Zhuang Autonomous Region., Results: 4 553 clinic Salmonella (S.) strains were isolated from the Shanghai network laboratories from 2005 to 2012. The top 10 serotypes would include 20 serotypes all belonged to A-F groups, while S. Pomona was next to S. Wandsworth, according to the non- A-F groups. Young children seemed to be susceptible to S. Pomona, and might cause bloody stools and super-infection. The top 10 serotypes from 1 805 foodborne Salmonella strains were significantly more extensive than those from the human S. Pomona strains, followed by those rare serotypes which were mostly isolated from turtle, sea-shellfish and reptiles. Antibiotic resistance of S. Pomona strains from other sources were significantly more severe than those from human samples, and belonged to A and B clones by means of PFGE. Clone A strains were non-epidemic strains which showed multi-drug resistance (MDR) to antimicrobials. Clone B was the main epidemic-causing strain that not resistant to drugs, which consisting B- I from young-age-groups and B-II were from the seniors. B-I strains were homologous to those from shellfish, tortoises and lizards, while B-II strains only showing homology to those from shellfish. One S. Pomona strain-MDR, isolated from human was homologous to 8 antimicrobials., Conclusion: S. Pomona was a quite common serotype among those rare serotypes, which showed higher pathogenicity to infants while genetic evolution might take place when comparing them with the strains isolated from the clinics in 2005. Surveillance programs should be intensified along with the early warnings systems on infections which were from seafood and reptiles.