Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

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

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 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 explore the self-management trajectory of patients with percutaneous coronary intervention (PCI) , in order to provide better guidance for disease self-management of patients with PCI.Methods:From April to December in 2019, a total of 15 patients with PCI who were treated and followed up in a Class Ⅲ Grade A hospital in Harbin and a Class Ⅲ Grade A hospital in Tianjin were selected as the research objects. All 15 patients were interviewed and recorded. Then the records were transcribed and analyzed with open coding, axial coding and selective coding according to the grounded theory put forward by Strass and Corbin, to identify the categories and core category.Results:The core category of disease self-management of patients undergoing PCI was "crisis-conscious path of PCI patient self-management", that was, the path of PCI patient self-management presented a dynamic process with the change of disease risk cognition. When patients were aware of the disease risk, they would enter the path of active health management, and when patients were unaware of the disease risk or risk cognition declines, they would enter the path of ignoring the disease self-management.Conclusions:Medical staff should pay attention to and strengthen the early postoperative risk awareness education of PCI patients; quantify patients' cognitive needs of health education and give targeted health education intervention measures; strengthen supervision and management outside the hospital, and establish the concept of lifelong self-management for patients.

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".

Objective To explore the clinical features,efficacy and prognosis of different treatments for children with achalasia of cardia(AC).Methods In this retrospective study,the clinical features,laboratory examination and treatment of 36 children with AC who had been admitted to Department of Gastroenterology,Beijing Children's Hospital,Capital Medical University from August 2006 to September 2015 were reviewed,and the efficacy and prognosis of different treatments were compared.The symptoms of the children were graded using the AC clinical symptom score(Eckardt score),and the Eckardt score ≤ 3 scores was defined as the effective treatment.SPSS 19.0 statistical software was used to analyze the data,and P<0.05 for the difference was statistically significant.Results Thirty-six children with AC included 24 boys and 12 girls.Ages ranged from 1.4 to 15.5 years old,with a mean age of(10.0±3.4)years old.Course of disease ranged from 1 month to 9 years,with a mean course of 0.5(0.2,3.0)years.In the 36 children,33 cases(91.7％)had vomiting,23 cases(63.9％)had dysphagia,16 cases(44.4％)had weight loss,and 9 cases(25.0％)had chest pain.The effective rates of treatment in surgical treatment group and drug treatment group were 100.0％(13/13 cases)and 71.4％(5/7 cases),respectively in 3 months,and there was no significant difference between the 2 groups(P=0.111).The effective rates of treatment were 100.0％(13/13 cases)and 50.0％(3/6 cases),respectively in 6 months,and the difference was statistically significant between the 2 groups(P=0.021).Within 12 months,there was no recurrence in surgical treatment group and the effective rate was 100.0％.Children in drug treatment group had 1 case who stopped taking medicine,while the other children received surgical treatment in other hospitals due to poor drug treatment.Conclusions Drug and surgical treatment of AC both have good short-term effect,however,the medium and long-term efficacy of surgical treatment is higher than that of drug treatment in children.Symptomatic relief is more stable,and symptom is not easy to relapse for the children with surgical treatment.

Objective This study aimed to explore the incidence trends and onset features of scarlet fever during the years of epidemic,from 2006 to 2015,in Beijing.Methods Spatial,temporal and population distributions,prognosis of the reported cases and surveillance data on scarlet fever and other streptococcal infections (including the patients of streptococcal infection,tonsillitis and isthmitis) were analyzed by the descriptive epidemiological methods.Results A total of 27 987 scarlet fever cases were reported from 2006 to 2015,with the incidence rates as 7.04 to 18.53 per 100 000 persons during these years,except for 2011.A total of 6 152 cases were reported in 2011,with the incidence of 31.37 per 100 000 persons,significantly higher than the average levels of the other years.There were more cases reported in rural-urban continuum,in summer and winter,with most of the cases were children in primary schools and infant-institutes.From May to December in 2011,4 332 cases were interviewed three weeks after the disease onset,and their conditions improved or recovered,with no death or complication appeared at the follow-up period.There were 2 725 cases of scarlet fever and 104 013 clinical cases of streptococcal infections reported in 36 surveillance hospitals during the same period.The ratio between numbers of scarlet fever cases and streptococcal infection was 1 ∶ 38.17.The weekly numbers of scarlet fever were remarkably correlated to the streptococcal infections,with a Pearson's correlation coefficient as 0.729 (P＜0.001).Accordingly,we estimated that about 21.4 thousand clinical cases of streptococcal infections that were caused by Group A streptococcus in 2011,in Beijing.Conclusions Incidence of scarlet fever in 2011 was significantly higher than the average levels of other years in Beijing,but characteristics on spatial,temporal and population distributions of scarlet fever remained the same,with good prognosis of the reported cases.A large number of culture-positive Group A streptococcus infections among all the clinical cases of streptococcal infection might have been served as important source on septic infection,of scarlet fever.

Objective To study the sensitivity and specificity of the Chinese eating assessment tool (EAT-10) in screening acute stroke patients for oropharyngeal dysphagia (OD).Methods A total of 130 inpatients with acute stroke were screened using the Chinese EAT-10.On the same day they were also screened using the gold standard technique for diagnosing dysphasia-videofluoroscopy.A receiver operating characteristics (ROC) curve was developed to study EAT-10's sensitivity and specificity.A Youden index,positive predictive value (PPV),negative predictive value (NPV),and positive and negative likelihood ratios (LHR+ and LHR) were quantified.Results According to the ROC curve,a cut-off point of 1 (EAT-10 score≥ 1) gave the best sensitivity (77.9％),the highest NPV (73.2％),with 66.1％ specificity,71.6％ PPV,2.30 LHR+ and 0.33 LHR in screening for OD.The test-retest reliability was above 0.7.An investigator consistency reliability test showed good repeatability,and the consistency between each item and the mean total score was high.Conclusion The Chinese EAT-10 has good test-retest reliability and investigator consistency.The optimal cut-off point is 1,with good sensitivity and NPV at scores ≥ 1.The test can be recommended as a screening tool for OD in acute stroke patients.

Objective:To study the influence of rutin in the morphology of renal tissue of the diabetic mice induced by streptozotocin(STZ), and to clarify the effect of rutin on the kidney tissue damage.Methods:Twelve mice of the total 70 Kunming mice were used as normal group, the other were used to estabish type 1 diabetes mouse models by intraperitoneally injected with STZ (62.5 mg·kg-1), once daily for 5 d.The successfully established model mice were randomly divided into model group,low dose (50 mg·kg-1)of rutin group, high dose (100 mg·kg-1) of rutin group and irbesartan group (45 mg·kg-1).The mice in model group and normal group were given the carboxy methyl cellulose(CMC) and the other mice were given drugs by intragastric administration once daily for 8 weeks accordingly.The weight and blood glucose of the each mouse were determined.Full automatic biochemical analyzer was used to detect the levels of serum creatinine (Cre) and blood urine nitrogen (BUN) of the mice , and the kidney index was calculated.The morphology of renal tissue was observed by HE staining, Masson staining and electron microscope.Results:After injection of STZ,the model success rate was up to 98%.Compared with normal group, there was no significant difference in the weight of the mice in other groups before administration(P>0.05).After administration of rutin, the weights of the mice in model group, low dose of rutin group, high dose of rutin group and irbesartan group were significantly decreased (P<0.05).Compared with model group, the levels of blood glucose of the mice in low and high doses of rutin groups were significantly decreased(P<0.05);the levels of Cre and BUN were significantly reduced (P<0.05);the kidney index of the mice in high dose of rutin group was significantly decreased (P<0.05).Compared with normal group,the kidney tissue of the mice in model group was seriously damaged;glomerular was weaked, the kidney tissue fibrosis was serious, glomerular basement membrane was diffusely thickened and foot process was coalesced or overgrow.Compared with model group,the degree of injury of the mice in low and high doses of rutin groups were significantly improved, especially in high dose of rutin group.Conclusion:Rutin can improve the renal function of diabetic mice induced by STZ and reduce the degree of renal tissue damage in the diabetic mice