Objective To explore the impact of meteorological factors on the incidence of scarlet fever in Xicheng District of Beijing, and to provide a scientific basis for formulating targeted prevention and control measures. Methods Daily scarlet fever incidence data and corresponding meteorological data from 2010 to 2019 in Xicheng District of Beijing were collected. Using year, month, and day of the week as time-stratified variables, a conditional logistic regression model with a time-stratified case-crossover design was employed to analyze the impact of different meteorological factors on the number of scarlet fever cases in Xicheng District, while controlling for long-term trends, seasonality and other confounding factors. Results From 2010 to 2019, a total of 3,195 cases of scarlet fever were reported in Xicheng District, with an average annual incidence rate of 24.17/100 000. The overall trend showed fluctuating decline, during which three incidence peaks occurred, with the highest incidence rate observed in 2011. No severe or fatal cases were reported. The incidence of scarlet fever exhibited a distinct seasonal bimodal distribution, primarily concentrated between April to June and November to January of the following year. The conditional logistic regression results showed that the average relative humidity and average temperature were positively correlated with scarlet fever cases (β=0.0203, β=0.0613, P＜0.001), while the average vapor pressure was negatively correlated with scarlet fever cases (β=-0.1468, P＜0.001). Increases average relative humidity and average temperature were risk factors for scarlet fever incidence (OR=1.0205，95%CI=1.0150 -1.0261；OR=1.0632，95%CI=1.0379 -1.0891). For every 1.00% increase in average relative humidity, the number of scarlet fever cases increased by 2.05% (1.50% –2.61%). Similarly, for every 1^。C rise in average temperature, the number of cases increased by 6.32% (3.79% – 8.91%). In contrast, an increase in average vapor pressure had a protective effect against scarlet fever (OR=0.8635,95%CI=0.8392-0.8885). For every 1 hPa increase in average vapor pressure, the number of scarlet fever cases decreased by 13.65% (11.15%–16.08%). Conclusion The average relative humidity, average temperature and average vapor pressure are the primary meteorological factors influencing the incidence of scarlet fever in Xicheng District of Beijing, and can be utilized as indicators for the prevention, control, surveillance and early warning of scarlet fever.

ObjectiveTo understand the epidemic characteristics of influenza in Beijing from 2023 to 2024, and to provide a scientific basis for the prevention and control of influenza. MethodsData on influenza-like illness (ILI) from secondary level and above hospitals, etiology surveillance data, and influenza clusters outbreaks data from 2023‒2024 were used to analyze the epidemic trend and pathogenic characteristics of influenza. Furthermore, an influenza comprehensive index was used to categorize the epidemic intensity at the severity level. ResultsA total of 2 065 857 ILI cases were reported in 2023‒2024 epidemic season, and the percentage of ILI was 3.67%. The age group of 5‒14 years accounted for the highest proportion of ILI (30.48%). A total of 41 766 throat swabs from ILI were detected, with a positive rate of 17.28%.A (H3N2) (51.86%) and B Victoria (41.93%) were the most prevalent subtypes of influenza virus. Clustered influenza outbreaks occurred mainly in primary schools (57.78%) and middle schools (35.55%), mainly caused by the influenza A (H3N2) subtype (85.93%). According to the influenza comprehensive index (I), the period of influenza activity and above (I>0.5) lasted for a total of 37 weeks, accounting for 71.15% of the entire influenza season. ConclusionCompared with previous years, the epidemic level of influenza in Beijing was increased in 2023‒2024, and the peak time became earlier. The comprehensive index method can objectively evaluate the level of influenza epidemic and provide suggestions for the future prevention and control of influenza in Beijing.

Objective:To analyze the effect of influenza vaccination on influenza cluster epidemic in primary and secondary schools in Beijing during the 2023-2024 surveillance season and provide evidence for the improvement of influenza vaccination strategies.Methods:The incidence data of influenza cluster epidemic and influenza vaccination coverage in the schools in Beijing during 2023-2024 were collected. Descriptive epidemiological methods were used to analyze cluster epidemic characteristics, and χ2 test was used to compare incidence differences between groups, and OR value and vaccine effectiveness [VE=(1- OR)×100%] were calculated. A negative binomial regression model was used to evaluate the association between school vaccination rates and cluster epidemic risk. Joinpoint regression was used to analyze trends in relative risk ( RR) with increasing vaccination coverage and to determine the optimal vaccination threshold. Results:A total of 126 influenza cluster epidemic were reported in 115 primary and secondary schools in Beijing during 2023-2024 with the median size of 15 case, the average attack rate was 36.26% (2 033/5 607). The epidemics mainly occurred in urban area (70, 55.56%). Primary schools were the main setting (78, 61.90%), and influenza A(H3N2) was the predominant subtype (108, 85.71%). The overall influenza vaccination coverage in the primary and secondary students was 54.26%, while the average vaccination in classes affected by the epidemics was 58.57%. The overall protection rate was 47.62%, the protection rate was higher in primary schools (49.65%) than in secondary schools (46.60%). The protection rates against influenza A(H1N1)pdm09 (80.93%) and influenza B (Victoria lineage) (81.65%) were significantly higher than that against influenza A(H3N2) (44.19%). When school vaccination coverage reached ≥76.00%, the epidemic risk decreased by 52.82%.Conclusions:Even the match between influenza vaccine strains and circulating strains is suboptimal, increasing influenza vaccination coverage in schools can effectively reduce the risk for influenza cluster epidemic. In the future, measures such as policy guidance and public health education should be taken to further improve vaccination coverage, thereby establishing herd immunity and reducing the transmission risk of influenza in schools.

Objective:To analyze the effect of influenza vaccination on influenza cluster epidemic in primary and secondary schools in Beijing during the 2023-2024 surveillance season and provide evidence for the improvement of influenza vaccination strategies.Methods:The incidence data of influenza cluster epidemic and influenza vaccination coverage in the schools in Beijing during 2023-2024 were collected. Descriptive epidemiological methods were used to analyze cluster epidemic characteristics, and χ2 test was used to compare incidence differences between groups, and OR value and vaccine effectiveness [VE=(1- OR)×100%] were calculated. A negative binomial regression model was used to evaluate the association between school vaccination rates and cluster epidemic risk. Joinpoint regression was used to analyze trends in relative risk ( RR) with increasing vaccination coverage and to determine the optimal vaccination threshold. Results:A total of 126 influenza cluster epidemic were reported in 115 primary and secondary schools in Beijing during 2023-2024 with the median size of 15 case, the average attack rate was 36.26% (2 033/5 607). The epidemics mainly occurred in urban area (70, 55.56%). Primary schools were the main setting (78, 61.90%), and influenza A(H3N2) was the predominant subtype (108, 85.71%). The overall influenza vaccination coverage in the primary and secondary students was 54.26%, while the average vaccination in classes affected by the epidemics was 58.57%. The overall protection rate was 47.62%, the protection rate was higher in primary schools (49.65%) than in secondary schools (46.60%). The protection rates against influenza A(H1N1)pdm09 (80.93%) and influenza B (Victoria lineage) (81.65%) were significantly higher than that against influenza A(H3N2) (44.19%). When school vaccination coverage reached ≥76.00%, the epidemic risk decreased by 52.82%.Conclusions:Even the match between influenza vaccine strains and circulating strains is suboptimal, increasing influenza vaccination coverage in schools can effectively reduce the risk for influenza cluster epidemic. In the future, measures such as policy guidance and public health education should be taken to further improve vaccination coverage, thereby establishing herd immunity and reducing the transmission risk of influenza in schools.

COVID-19 ; China/epidemiology* ; Disease Outbreaks ; Humans ; SARS-CoV-2

Objective:To analyze the relationship between the cycle threshold ( Ct) values of N gene of COVID-19 cases and the secondary attack risk in close contacts, and identify the relationship between respiratory viral load and infectivity in COVID-19 cases. Methods:The COVID-19 cases with records of Ct values of N gene within 0-7 days of onset were selected, and their close contacts were recruited as the subjects of study. We collected the information of close contacts, including name, gender, age, isolation mode, exposure mode and outcome (whether they were infected with SARS-CoV-2 or not) and other variables. Multivariate logistic regression models were used to identify the relationship between Ct values of N gene of COVID-19 cases and secondary attack risk in close contacts. Results:A total of 1 618 close contacts were recruited, in whom 77 were confirmed as symptomatic or asymptomatic COVID-19 patients with overall secondary attack rate of 4.8%. The multivariate logistic regression analysis indicated that eating together ( OR=2.741, P=0.054), living together ( OR=9.721, P<0.001), non-centralized isolation ( OR=18.437, P<0.001) and COVID-19 case's values of N gene within 0-7 days of onset being <20 ( OR=8.998, P=0.004) or 20-25 ( OR=3.547, P=0.032) were significantly associated with higher likelihood of being infected with SARS-CoV-2 in close contacts. Conclusion:The results indicated that positive relationship exists between respiratory viral load and infectivity in COVID-19 cases, suggesting that Ct values of N gene can be used as an early warning indicator for the management of close contacts of COVID-19 cases.

Objective:To analyze epidemiological characteristics of influenza in Beijing during 2015—2020 influenza seasons.Methods:Weekly numbers of cases with influenza-like illness and weekly data of virologic surveillance was used to analyze epidemic trend and characteristics of influenza.Results:From June 26, 2015 to June 28, 2020, influenza-like illness (ILI) was 1.58%. A total of 49868 pharyngeal swab samples were collected from ILI cases, and positive rate of influenza virus nucleic acid was 16.32% by real-time PCR. Of these positive samples, 40.89% (6 474) were A(H3N2), 27.86% (4 410) were A (H3N2), 20.78% (3 290) were B/Victoria lineage, and 10.09%(1597) were B/Yamagata lineage. There were correlation between ILI and positive rate of influenza virus ( r=0.796, P<0.001), and ILI percentage and positive rate were also correlated ( r=0.808, P<0.001). The active duration in 2018—2018, 2018—2019 influenza seasons were longer. Weekly numbers of influenza-like illness cases of 2017—2018, 2018—2019 influenza seasons were higher (49 628 and 71 555), peak value of positive rate in the above seasons was higher (58.51% and 57.08%). Conclusions:The epidemic characteristics of influenza during 2015—2020 years was in accordance with the temperate regions of the northern hemisphere. There were longer active period and higher epidemic level in 2017—2018, 2018—2019 influenza seasons. The dominant influenza virus subtypes varied in the different seasons.

Objective To calculate both the epidemic and intensity thresholds for different levels in Beijing and to establish a tiered alert system in the 2018-2019 influenza season as well as to evaluate the performance of calculated thresholds.Method Weekly count of influenza-like illness and percentage of influenza-like illness (ILI％) of the last five influenza seasons were modeled by 'moving epidemic method'(MEM) to calculate the influenza epidemic and intensity thresholds at different levels.A cross-validation procedure was used to evaluate the performance.Indicators of Matthew correlation coefficient,Youden's index,sensitivity and specificity were calculated.Results For weekly count of influenza-like illness,data showed that the epidemic threshold for 2018-2019influenza season was 12 984 and the medium,high and very high intensity thresholds were 22 503,37 589,47 157,respectively.Matthew correlation coefficient of the epidemic threshold was 62％ and youden's index as 60％,sensitivity as 69％,specificity as 91％.Data on weekly ILI％,the epidemic threshold for 2018-2019 influenza season was 1.66％,with medium,high and very high intensity thresholds as 2.46％,3.84％ and 4.66％,respectively.The overall Matthew correlation coefficient of the epidemic threshold was 59％,with 54％ for the Youden's index,sensitivity as 60％ and specificity as 94％.Conclusions MEM produced a good specific signal for detecting the influenza epidemics and the accuracy of the method was acceptable.The early warning performance regarding the application of weekly count on influenza-like illness was slightly better than ILI％.This method could be applied in the practical influenza epidemic alert "work in Beijing".

Background:Chronic atrophic gastritis(CAG)is a kind of chronic gastritis with atrophic changes of gastric mucosa. The studies on peripheral blood biomarkers in CAG are rare. Aims:To investigate the methylation of peripheral blood CpG sites in Runx3 gene promoter region in CAG patients. Methods:Eighty-two mild CAG patients,73 moderate to severe CAG patients from June 2013 to May 2014 at Daqing Oilfield General Hospital were enrolled,and 45 patients with normal gastric mucosa were served as controls. The methylation of CpG sites in Runx3 gene promoter region was measured by MALDI-TOF-MS. mRNA expression of Runx3 was determined by fluorescent quantitative PCR,and the protein expression of Runx3 was determined by Western blotting. Results:Compared with the control group and mild CAG group,methylation levels of CpG13,CpG14 and CpG15 sites in Runx3 gene promoter region were significantly increased in moderate to severe CAG group(P < 0. 05),the mRNA and protein expressions of Runx3 were significantly decreased( P < 0. 05). No significant differences in methylation of CpG sites in Runx3 gene promoter region and mRNA and protein expressions of Runx3 were found between mild CAG group and control group( P >0. 05 ). Conclusions:The hypermethylation of peripheral blood CpG13,CpG14 and CpG15 sites in Runx3 gene promoter region can inhibit the expression of Runx3 in CAG patients,and can be used potentially as the biomarker for clinical staging of CAG.

This study was aimed to establish a method for the content determination of three components in Tribulus terrestris L., in order to compare index components of different growing periods, production places and medical parts for the scientific explanation of the harvesting time and growing places. Contents of three effective components inTribulus terrestris L., which were quercetin-3-O-β-D-gentiobioside, isorhamnetin-3-O-β-D-gentiobioside and Terrestrinone A2, were determined by HPLC. The results showed that contents of three evaluation indexes all gradually increased until June and then started reducing. The contents in all evaluated indexes were in the order of the stem and leaf > fruit > root. And the content in the root was below the detection limit. The content indexes ofTribulus terrestris L. of the Inner Mongolia were much higher than that of other regions. It was followed byShandong,Hebei andShanxi province. It was concluded that the method was simple and accurate with good repeatability and stability, which was suitable for quality control ofTribulus terrestris L.