Objective To explore the etiology and epidemiological characteristics of fever and rash syndrome a mong children under the age of five years in Northwest China from 2009 to 2015.Methods Descriptive epidemiological analysis was conducted based on the monitoring data in sentinel hospitals,which was from the information management system of national infectious disease monitoring from 2009 to 2015 in Gansu,Qinghai,Inner Mongolia and Xinjiang.Results The results showed that the major pathogens of fever and rash syndrome among children under the age of five years were enterovirus,measles virus,varicella-zoster virus (VZV) and rubella virus.The major pathogens among children in the age group of 0-years and in the age group of 1-5 years were measles virus and enteroviruses,respectively.Among the positive cases of enterovirus,the positive detectable rates of human enterovirus 71 (EV71) and coxsackie A16 (CA16) were 47.18％ and 45.59％,respectively.The incidences of enterovirus and measles virus infection were mainly concentrated on May to July and March to May,respectively.Conclusions The major pathogens of fever and rash syndrome among children under the age of five years in Northwest china were enterovirus and measles virus with seasonal epidemic characteristics.Therefore,the prevention and control of measles and hand-foot-mouth disease should be strengthened.

Objective:To investigate the genetic diversity and molecular epidemiology of Bordetella pertussis in Shaanxi province, and analyze the possible reasons of resurgence in this region. Methods:We characterized clinical isolates collected during 2012-2017 using multilocus antigen sequence typing (MAST) and multilocus variable-number tandem repeat analysis (MLVA).Results:The circulating strains and vaccine strains were different in molecular characteristics. The majority (95%) of the isolates were typed as prn1/ ptxP1/ ptxA1/ fim3-1/ fim2-1. In addition, eight MLVA types (MTs) and eight PFGE profiles were identified, respectively. MT195, MT55 and MT104 were dominant and MT195 continually increased annually. Conclusions:The genetic characteristics of the current strains in Shaanxi province were different from those of the vaccine strain. The evolution through genetic variation might be one of the reasons for the recurrence of pertussis in this region.

Objective:To analysis the macrolide resistance, molecular characteristics and plused-field gel electrophoresis(PFGE) type of Bordetella pertussis ( Bp), explore the possible resistance mechanism and the relationship between PFGE types and macrolide resistance profiles. Methods:Erythromycin, azithromycin and clarithromycin susceptibility of clinical isolates during 2016 to 2018 was determined by E-test. PCR was used to detect the drug-resistant genes and mutation sites. PFGE were employed to do molecular typing for the strains.Results:Thirty-five strains were isolated, of which 27 strains were resistant to all three antibiotics, two strains were resistant to erythromycin and azithromycin, and six strains were sensitive to all three antibiotics. Partial macrolide resistant strains carried the methylase gene ermA (27.6%, 8/29) and ermB (31.0%, 9/29); A2047G site mutation was detected in macrolide-resistant strains, while no drug-resistant genes or mutation sites were found in sensitive strains. Resistant strains were classified into BPSR23 and BPFINR9 types, while sensitive strains were other profiles. Conclusions:The clinical isolated Bp were seriously resistant to erythromy and showed signs of resistance to other macrolides. The acquisition of methylase gene and mutation of A2047G site might be the main mechanism of resistance. The macrolide resistance might have has a certain correlation with PFGE profile.

To evaluate the estimation of prevalence ratio (PR) by using bayesian log-binomial regression model and its application,we estimated the PR of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea in their infants by using bayesian log-binomial regression model in Openbugs software.The results showed that caregivers' recognition of infant's risk signs of diarrhea was associated significantly with a 13％ increase of medical care-seeking.Meanwhile,we compared the differences in PR's point estimation and its interval estimation of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea and convergence of three models (model 1:not adjusting for the covariates;model 2:adjusting for duration of caregivers' education,model 3:adjusting for distance between village and township and child month-age based on model 2) between bayesian log-binomial regression model and conventional log-binomial regression model.The results showed that all three bayesian log-binomial regression models were convergence and the estimated PRs were 1.130(95％CI:1.005-1.265),1.128(95％CI:1.001-1.264)and 1.132(95％CI:1.004-1.267),respectively.Conventional log-binomial regression model 1 and model 2 were convergence and their PRs were 1.130(95％ CI:1.055-1.206) and 1.126(95％ CI:1.051-1.203),respectively,but the model 3 was misconvergence,so COPY method was used to estimate PR,which was 1.125 (95％CI:1.051-1.200).In addition,the point estimation and interval estimation of PRs from three bayesian log-binomial regression models differed slightly from those of PRs from conventional log-binomial regression model,but they had a good consistency in estimating PR.Therefore,bayesian log-binomial regression model can effectively estimate PR with less misconvergence and have more advantages in application compared with conventional log-binomial regression model.

Objective To explore the incidence and risk factors of gout in Jinchang cohort and provide scientific evidence for the prevention and control of gout.Methods People without gout detected by baseline survey in Jinchang cohort were selected as study subjects.All the subjects were followed up through questionnaire interview,physical examination as well as laboratory test from January 24,2013 to November 24,2015.Cox regression model was used to analyze the risk factors for gout in Jinchang cohort.In addition,log-linear model was used to analyze the interaction between risk factors.Results A total of 33 153 subjects were followed up,and there were 277 newly diagnosed gout cases in the cohort.The overall incidence of gout was 0.8％.The incidence of gout in males was higher than that in the females,but the incidence of gout in males and females was similar after the age of 60 years.Cox regression analysis showed that age ＞40 years (at age 40 to 59 years:HR=2.982,95％CI:1.503-5.981;at age 60 to 91 years:HR=2.588,95％CI:1.107-6.049),alcohol abuse (HR=2.234,95％CI:1.128-4.427),obesity (HR=2.204,95％CI:1.216-3.997),diabetes (HR=2.725,95％CI:1.500-4.950) and high uric acid (HR=5.963,95％CI:3.577-9.943) were risk factors for gout,while weekly beans intake ≥0.25 kg (HR=0.528,95％CI:0.345-0.808) and regular physical exercise (HR=0.499,95％ CI:0.286-0.869) were protective factors for gout.The analysis with log-linear model showed that there were two order effects between the risk factors.Conclusions Age,beans intake,alcohol abuse,physical exercises,obesity,diabetes and high uric acid were important factors influencing the incidence of gout.It is important to have healthy lifestyle and dietary habits,receive regular health examination to prevent and control the incidence of gout in this cohort.

Objective To understand the dominant pathogens of febrile respiratory syndrome (FRS) patients in Gansu province and to establish the Bayes discriminant function in order to identify the patients infected with the dominant pathogens.Methods FRS patients were collected in various sentinel hospitals of Gansu province from 2009 to 2015 and the dominant pathogens were determined by describing the composition of pathogenic profile.Significant clinical variables were selected by stepwise discriminant analysis to establish the Bayes discriminant function.Results In the detection of pathogens for FRS,both influenza virus and rhinovirus showed higher positive rates than those caused by other viruses (13.79％,8.63％),that accounting for 54.38％,13.73％ of total viral positive patients.Most frequently detected bacteria would include Streptococcus pneumoniae,and haemophilus influenza (44.41％,18.07％) that accounting for 66.21％ and 24.55％ among the bacterial positive patients.The original-validated rate of discriminant function,established by 11 clinical variables,was 73.1％,with the cross-validated rate as 70.6％.Conclusion Influenza virus,Rhinovirus,Streptococcus pneumoniae and Haemophilus influenzae were the dominant pathogens of FRS in Gansu province.Results from the Bayes discriminant analysis showed both higher accuracy in the classification of dominant pathogens,and applicative value for FRS.

OBJECTIVEThe purpose of this study was to explore the spatial distribution and spatial clustering of hand-foot-mouth disease (HFMD) in Gansu, 2012.

METHODSSpatial autocorrelation and Spatial scanning analysis were used to conduct spatial statistical analyses for the HFMD at the county/district level.

RESULTSHFMD cases did not show a random distribution but with significant spatial aggregation. When Local Autocorrelation analysis was applied at the county/district level, with nine hot spot areas as Jiayuguan, Yumen, Dunhuang, Jinta, Suzhou, Chengguan, Anning, Xigu and Gaolan, were discovered. Four statistically significant HFMD clusters were identified by spatial scan statistics.

CONCLUSIONHFMD was noticed geographically clustered in Gansu in 2012. Results from this study indicated that the spatial autocorrelation and spatial scanning analysis could effectively detect the areas which presenting significant clusters. Cluster Detection System (CDS) could provide evidence for the development of an effective measure concerning the prevention and control of HFMD.

OBJECTIVETo understand the spatial-temporal specific incidence of pulmonary tuberculosis (TB) in Gansu.

METHODSThe county-based incidence of pulmonary TB in Gansu from 2009 to 2013 was used to calculate Moran's I and G statistics, and analyze the spatial-temporal distribution of areas with different pulmonary TB incidences.

RESULTSThe spatial correlation in incidence of pulmonary TB was found in Gansu from 2009 to 2013 (P<0.001), and the hot spot areas were mainly in Hexi area, Linxia, part of Dingxi, while the cold spot areas were in Lanzhou, part of Dingxi, Tianshui, Pingliang and Qingyang. Spatial-temporal analysis showed that the clustering of high pulmonary TB incidence areas were most likely in the Hexi area during 2009-2010 (LLR=3,031.10, RR=2.27, P<0.001), and the clustering of low pulmonary TB incidence areas were most likely in Lanzhou during 2011-2013 (LLR=1,545.52, RR=0.37, P<0.001).

CONCLUSIONThe analysis on spatial and spatial-temporal specific incidences of pulmonary TB in Gansu from 2009 to 2013 indicated that Hexi area is the key area in pulmonary TB prevention and control in Gansu.

Objective: To construct Bayes discriminant function for clinical classification of common and severe Japanese encephalitis (JE) cases, and to identify cases accurately with quantitative indicators. Methods: Samples of confirmed common and severe JE cases reported by the epidemic surveillance system of Gansu Provincial Center for Disease Control and Prevention from 2005 to 2017 were collected. Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis were used to screen meaningful clinical indicators, so as to construct and evaluate Bayes discriminant function. Results: There were 256 common JE cases and 257 severe JE cases. There were no significant differences in sex, age and occupation distributions between the two groups (P>0.05) and there was significant difference in case fatality rate (P<0.05). Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis, combined with using related literature, to screen 11 clinical indicators for the construction of Bayes discriminant function. Interactive validation showed that the sensitivity of discriminant function was 71.48% (95%CI: 65.53%-76.93%) and the specificity was 73.93% (95%CI: 68.11%-79.19%). The area under ROC curve was 0.761 (95%CI: 0.720-0.803) and the total accuracy rate was 72.71%. Conclusion Bayes discriminant function can be used to identify common and severe JE cases more accurately, which is helpful for the reasonable treatment and good prognosis of JE patients.

Objective: To investigate the incidence and rank of chronic obstructive pulmonary disease and pneumoconiosis to the workers in different occupational positions in Jinchang Cohort. Methods: In January 2014, a cohort of follow-up population in jinchang city was taken as the research object, 17843 individuals among follow-up populations in Jinchang Cohort Study, removed the individuals with chronic obstructive pulmonary disease and pneumoconiosis before 2013, and counted the new incidence individuals diagnosed by the A-Class hospital in Grade III in Jinchang City, Gansu Province, as the investigation objects to investigate the incidence rate & rank of chronic obstructive pulmonary disease and pneumoconiosis. The statistical significance was tested by chi-square test. Results: The 2-year incidence rate of Chronic Obstructive Pulmonary Disease and Pneumoconiosis in the population of Jinchang Cohort Study were 11.60‰, 13.51‰ for male and 8.46‰ for female. the ranks of 2-year incidence rates of chronic bronchitis, emphysema, pneumoconiosis and other phenotypes of chronic obstructive pulmonary disease were 7.06‰、3.42‰、0.84‰、0.34‰, respectively. Incidence rate of chronic bronchitis among administrators and executive staffs were 10.45‰; incidence rate of chronic bronchitis among service staffs were 10.45‰; incidence rate of pneumoconiosis among mining staffs were 3.44‰. Conclusion The first incidence rank of chronic obstructive pulmonary disease and pneumoconiosis in Jinchang cohort is chronic bronchitis, and the risk factors are smoking and occupational exposure.