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.

Nonalcoholic fatty liver disease （NAFLD） is a multisystem disease associated with obesity， insulin resistance， and dyslipidemia and has a complex pathogenesis. Studies have shown that gut microbiota dysbiosis is closely associated with the onset of NAFLD， and traditional Chinese medicine treatment can improve the laboratory markers and clinical symptoms of NAFLD patients by regulating intestinal microbiota and its metabolites. This article elaborates on the association between NAFLD and gut microbiota， the involvement of gut microbiota dysbiosis in the pathogenesis of NAFLD， and the possible mechanism of traditional Chinese medicine treatment in improving NAFLD from the perspective of gut microbiota， in order to provide new ideas for the treatment of NAFLD.

Objective To explore the characteristics of blood vitamins A, B2, B6, B12, D, E, K1, K2 and folic acid and their correlation with severity in patients with metabolic-related fatty liver disease (MAFLD). Methods　From September to December 2022, a total of 473 cases of residents were recruited through community MAFLD screening activities and their health information was obtained through questionnaire survey and physical examination. The severity of hepatic steatosis was determined with FibroScan, and vitamin concentrations were determined with liquid chromatography-tandem mass spectrometry. Two independent samples' t-tests were used to assess the differences between the two groups, and univariate chi-square tests and multivariate logistic regression analysis were used to explore the related factors of MAFLD. Results　Of the 473 inhabitants, 195 (41.23%, 195/473) met the diagnostic criteria for MAFLD, including mild 43 (22.05%, 43/195) cases of fatty liver, 88 (45.13%, 88/195) cases of moderate fatty liver, and 64 (32.82%, 64/195) cases of severe fatty liver. Using healthy residents collected during the same period as controls, the overall mean of vitamins A, E, K1, and K2 in the MAFLD group was higher than that of the healthy group, with a statistical difference (P<0.05). Furthermore, the concentrations of vitamins A, E, K1 and K2 increased with the severity of fatty liver [R=0.149, P=0.004; R=0.245, P<0.001; R=0.110, P=0.032; R=0.129，P=0.012]. There were statistically significant differences (P<0.05) in the blood levels of vitamin A and E between patients with moderate or severe fatty liver and the healthy population. The blood vitamins K1 and K2 in severe fatty liver patients were also different from those of healthy people (P<0.05). However, there was no significance between folic acid, vitamin D, B2, B6, B12, and MAFLD (P>0.05). Through univariate chi-square analysis and multivariate logistic regression analysis, it was found that male [Wald=5.789, P=0.034，OR=1.598(1.037-2.463)] and vitamin E≥8.13 μg/mL[Wald=14.632，P<0.001，OR=2.378(1.522-3.674)] were risk factors for moderate and severe MAFLD. Conclusions The concentrations of vitamin A, E, and K in the blood are increased in patients with MAFLD compared to the healthy population, and they are positively correlated with the severity of MAFLD. ale gender and high levels of vitamin E may be related to moderate to severe MAFLD.

The gene encoding regulatory subunit 15 A of protein phosphatase 1 produces a protein that is a universally present protein phosphatase in eukaryotic cells.In this study,genomic DNAs were extracted from the blood of 89 Chinese Holstein cows and were used as templates for PCR amplification of the target fragment of the PPP1R15A gene.The product was tested and a polymor-phic site,E3-250T＞A was found.The polymorphism of this side and its correlation with milk pro-duction traits in Chinese Holstein cattle were statistically analyzed using SPSS 23.0 software.The findings revealed three genotypes at this site:AA,AT and TT.Cows possessing the AT and TT genotypes exhibited significant differences(P＜0.01)in milk fat and solid non-fat content com-pared to those with the AA genotype.While no significant differences were noted for other milk production traits,including milk yield,protein,lactose,somatic cell count,blood urea nitrogen,and corrected milk.The identification of functional SNPs in the PPP1R15A gene provides a theoretical basis for further research and identification of causal variations in the cow PPP1R15A gene.

To analyze the epidemiological characteristics of acute respiratory infections (ARIs) during the autumn-winter season in Beijing, providing evidence for the prevention, control, diagnosis, and treatment of ARIs.

In recent years,cortisol has been used as a biomarker to assess stress in dogs.To evaluate the welfare of dogs,we reviewed cortisol levels and changes in dogs under various stresses.We explored the influential factors that relieve stress in accordance with variations in cortisol levels,to improve the measures which reduce stress in dogs.It is recommended to apply cortisol measurement and behavioral observation comprehensively to evaluate stress in dogs more accurately.

ObjectiveTo conduct on-site epidemiological investigation， emergency response， tracing of infection source and analysis of a confirmed COVID-19 case of a foreign airline cargo service staff member in Shanghai’s international airport， aiming to provide reference for prevention of imported COVID-19 cases under regular prevention and control of COVID-19. MethodsA retrospective field epidemiological investigation was conducted to collect information of basic characteristics， illness onset， diagnosis， treatment， clinical manifestations， exposure history and risk factors within 14 days before onset， close contacts， close contacts of close contacts， and key places related to activity trajectories. Respiratory tract specimens of cases and contacts were collected for detection of SARS-CoV-2 by real time RT-PCR （rRT-PCR）. Emergency response， including infection source analysis and contact management， was conducted. ResultsThe case developed pharyngeal itch on July 28， 2021， and fever on the 30th， and went to the hospital for treatment twice on the 31st. Because his specimen was positive for SARS-CoV-2 by rRT-PCR on August 1， he was isolated and treated on August 2 and diagnosed as a confirmed case of COVID-19. The case was a foreign airline cargo service member at an international airport. The two regular nucleic acid screenings of him as a high-risk occupation on July 21 and 28 were negative. He did not leave Shanghai within 14 days before the onset of illness. During July 22nd and 23rd， he was repeatedly exposed during work to the high-risk environment that may have been contaminated by SARS-CoV-2 and had contact with the crew of foreign airlines， and the personal protection was not standardized. None of the 67 close contacts and 567 close contacts of close contacts in Shanghai showed symptoms during the 14-day medical quarantine， and the specimens of them were all negative for SARS-CoV-2 by rRT-PCR. The results of genome sequencing analysis showed that the genomic homology between the virus of the case and the one of recent domestic local epidemic and the recent imported cases was low， and the homology with the overseas Delta mutant strain was higher than that of the domestic Delta mutant strain. ConclusionThe situation of prevention of COVID-19 import is still serious. It is necessary to conduct regular nucleic acid screening for high-risk occupational groups， strengthen the diagnosis and reporting awareness of medical institutions， effectively implement the prevention and control measures for people， objects， and environment at international airports， and further enhance the public's awareness of personal protection.

Clinical metagenomic next-generation sequencing (mNGS) entails unbiased shotgun sequencing of all microbial and host nucleic acids present in a clinical sample. By analyzing the microbiota diversity, taxonomic, and phylogenetic relationships of clinical specimens, metagenomics related analysis provides an opportunity to investigate substantial biological significance of different microbes. According to the published paper, most studies on mNGS mainly focused on the clinical impact evaluation. However, the studies focused on the analytical performance validation of mNGS before clinical application were rare. Here, a scheme, included intended use, method establishment, assay validation and standard operating protocol, for the laboratory validation of clinical metagenomics sequencing assay was provided by summarizing experiences of clinical laboratory department of Peking Union Medical College Hospital protocol and relevant research. In this scheme, we discussed important topics of mNGS laboratory validation as below: specimen type and pathogen list, bioinformatics pipeline setup, dry lab standard preparation and performance validation, mNGS workflow setup, background nucleotide acid evaluation, wet lab standard preparation and performance validation.

ObjectiveTo describe the epidemiologic, clinical, laboratory, and radiological characteristics and prognoses of COVID-19 confirmed patients in a single center in Beijing, China. Methods The study retrospectively included 19 patients with nucleic acid-confirmed SARS-CoV-2 infection at our hospital from January 20 to March 5, 2020. The final follow-up date was March 14, 2020. The epidemiologic and clinical information was obtained through direct communication with the patients or their family members. Laboratory results retrieved from medical records and radiological images were analyzed both qualitatively by two senior chest radiologists as well as quantitatively via an artificial intelligence software. Results We identified 5 family clusters (13/19, 68.4%) from the study cohort. All cases had good clinical prognoses and were either mild (3/19) or moderate (16/19) clinical types. Fever (15/19, 78.9%) and dry cough (11/19, 57.9%) were common symptoms. Two patients received negative results for more than three consecutive viral nucleic acid tests. The longest interval between an initial CT abnormal finding and a confirmed diagnosis was 30 days. One patient's nucleic acid test turned positive on the follow-up examination after discharge. The presence of radiological abnormalities was non-specific for the diagnosis of COVID-19. Conclusions COVID-19 patients with mild or no clinical symptoms are common in Beijing, China. Radiological abnormalities are mostly non-specific and massive CT examinations for COVID-19 screening should be avoided. Analyses of the contact histories of diagnosed cases in combination with clinical, radiological and laboratory findings are crucial for the early detection of COVID-19. Close monitoring after discharge is also recommended.
Adult ; COVID-19/diagnostic imaging* ; COVID-19 Nucleic Acid Testing ; Child ; China ; Female ; Humans ; Lung/diagnostic imaging* ; Male ; Middle Aged ; Retrospective Studies ; SARS-CoV-2 ; Tomography, X-Ray Computed

Objective:To analyze the epidemiological characteristics of imported COVID-19 cases in early phase in Shanghai, introduce measures and provide reference for prevention and control of imported COVID-19 cases.Methods:Data of imported COVID-19 cases in Shanghai reported as of 30 March, 2020 were obtained from National Notifiable Disease Report System of China CDC and field epidemiological investigation reports by CDCs in Shanghai. The information about measures of prevention and control was collected from official websites and platforms of the governments. Data cleaning and statistical analysis were performed with softwares of EpiData 3.1, Excel 2019 and SAS 9.4.Results:A total of 171 imported COVID-19 cases had been reported as of 30 March, 2020 in Shanghai, including 170 confirmed cases and 1 asymptomatic infection case. Among them, cases of Chinese nationality accounted for 71.3% (122/171) and cases of foreign nationality accounted for 28.7% (49/171). The median age of the cases was 23 years ( P 25, P 75: 18, 35 years), and the male to female ratio of the cases was 1.3∶1. Students accounted for 56.6% (97/171). About 45.6% (78/171) of the cases fell ill before arriving in Shanghai. The cases with mild or common clinical manifestation accounted for 96.5% (165/171) and no significant difference in clinical type was observed between overseas Chinese cases and foreign cases. The epidemic curve by diagnosis date reached peak on March 24, and the number of the cases gradually declined due to the closed-loop management process of joint port prevention and control mechanism. The 171 imported COVID-19 cases were mainly from 24 countries and regions, including the United Kingdom (64 cases, 37.3%), the United States (32 cases, 18.6%), France (19 cases, 11.0%) and Italy (16 cases, 9.4%). About 40.4% of the cases (69/171) planned to continue travelling to 21 other provinces and municipalities in China. Customs quarantine and community observation/detection points identified 43.9% (75/171) cases and 31.0% (53/171) cases, respectively. Conclusions:The imported COVID-19 cases in early phase in Shanghai were mainly young population and students accounted for high proportion. The imported risk of COVID-19 was consistent with the severity of the epidemic in foreign countries. The closed-loop management model of the joint port prevention and control mechanism plays an important role in the identification and management of the imported COVID-19 cases.