Molecular epidemiological characteristics of respiratory syncytial virus in pediatric patients in Gansu province from 2012 to 2017 / 中华实验和临床病毒学杂志

Objective@#To analyze the genotypes, amino acid vatiations and molecular epidemiological characteristics of respiratory syncytial virus (RSV) infection in pediatric patients in Gansu province for the future research.@*Methods@#A total of 4 556 respiratory tract specimens were colleted from pediatric patients under 10 years of age in five cities in Gansu from 2012 to 2017. These specimens were tested for RSV and its subtypes.The coding region of the RSV G gene was amplified using reverse transcription-polymerase chain reaction (RT-PCR) and sequenced for RSV positive specimens. Sequences were edited using DNA Star software. Sequence alignment and phylogenetic trees were built by MEGA 6.0 software.@*Results@#Out of 4 556 specimens, 1 135 (24.91%) were positive for RSV, totally 216 G protein sequences were obtained. RSV A isolates were clustered into three genotypes: NA1、NA3 and ON1. The nucleotides and amino-acid homology was 84.9%-100% and 77.3%-100%, respectively. The nucleotides and amino-acid homology between this study and prototype long strain was 81.2%-83.3% and 74.1%-88.0%. RSV B isolates were clustered into only BA9 one genotypes. The nucleotides and amino-acid homology was 97.7%-100% and 95.8%-100%, respectively. The nucleotides and amino-acid homology between this study and prototype CH18537 strain was 84.9%-85.7% and 77.9%-80.1%.@*Conclusions@#The genetic characteristics and the amino-acid changes were analyzed systematically using data of RSV G gene collected from 2012 to 2017 in Gansu province in this study. These data were used for analyses of the etiology, control and prevention of RSV infection.

Epidemiological and spatial-temporal distribution of several natural focus diseases in Gansu province, 2014-2018 / 中华流行病学杂志

Objective@#To analyze the epidemiological and spatial-temporal distribution of Brucellosis, epidemic encephalitis B and hemorrhagic fever with renal syndrome (HFRS) in Gansu province during 2014-2018 so as to provide evidence for the prevention and control of those diseases.@*Methods@#A database was established in Gansu province from 2014 to 2018, using the geographical information system. A spatial distribution map was drawn, with trend analysis and space-time clustering used to study the 3-dimention of the diseases, by using both ArcGIS 10.5 and SaTScan 9.6 softwares.@*Results@#Results from the trend surface analysis showed that the incidence of Brucellosis decreased gradually from north to south parts while the U type curve could reflect the distribution from the east to the west areas. Incidence of epidemic encephalitis B decreased significantly from south to north areas in the province, with incidence higher in the eastern than in the mid-west region. Difference on the incidence of HFRS was not significantly visible in the eastern and western regions, while the incidence was slightly higher in the southern than the northern parts of the province. Spatial and space-time clustering did exist among the 3 diseases in Gansu from 2014 to 2018. The areas with clusters of Brucellosis appeared in the eastern parts during 2014-2015, including 19 counties. The areas with secondary clusters of Brucellosis were seen in the Hexi district, including 4 counties, during 2017-2018. The areas with high incidence of epidemic encephalitis B were clustered in the middle and southeast areas, including 32 counties, during 2017-2018. Areas with most clusters of HFRS appeared in Min county of Dingxi city in 2018, with the areas of secondary clusters in 8 counties of the eastern areas in 2018.@*Conclusions@#The overall incidence rates of the 3 natural focus diseases were in a upward trend and showing obvious characteristics on spatial clustering. According to the distributive characteristics, effective measures should be developed accordingly.

Etiological characteristics of the first human derived Brucella melitensis type 3 in Gansu Province / 中华地方病学杂志

Objective To analyze the etiological characteristics of human Brucella strains isolated, and to improve the precision in control and prevention of brucellosis. Methods In 2016, blood samples were collected from patients in Jingyuan County Gansu Province, and tested via the Rose-Bengal Plate Agglutination Test (RBPT) and the tube agglutination test methods,and serological positive blood samples were inoculated to bidirectional blood culture bottle for culturing, and further identified by traditional biological classification method and the Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis species-specific PCR (AMOS-PCR). Multiple-locus variable number tandem repeat sequence analysis (MLVA) -16 was used to detect molecular typing and do cluster analysis. Results The isolated strain was identified by the traditional biological classification method, bacteria could grow in thionine and reddened dye, A and M factors agglutination tests were positive, Bk2phage treatment of bacterial strain cracking, but Tb, Wb phages were not cracked. AMOS-PCR amplification result showed a 731 bp band, which was a strain of Brucella melitensis. The results of MLVA-16 showed that there was a difference in the number of repeats on some Variaable Number of Tandem Repeat(VNTR)sites of the isolated strain. Clustering analysis showed that, the isolated strain was clusted into the same clade with the clustering of Brucella melitensis type 3 from GS-201605 in Gansu. And the clustering was similar compared with that of Zhejiang, Guangdong, Fujian and Yunnan. Conclusion Human brucellosis is a inputting transmission in Gansu Province, there is a genetic variation of genotype 3 sheep Brucella between Gansu Province and other domestic provinces.

Identification of Brucella strain isolated from sheep blood in Jingyuan County Gansu Province / 中华地方病学杂志

Objective To identify the Brucella strains isolated from sheep blood in Jingyuan County Gansu Province,and to provide scientific basis for Brucellosis control and prevention.Methods In 2016,blood samples from suspected cases of sheep were collected in the home of Brucellosis patient of Jingyuan County,and cultured with vaccination double blood bottles via the enrichment method,and the Brucella strains isolated from sheep were identified by traditional bio-typing,genus specific Brucella surface protein 31 PCR (BSCP31-PCR) and Brucella abortus,Brucella melitensis,Brucella ovis,Brucella suis species-specific PCR (AMOS-PCR),respectively.Results The isolated strain was identified using the traditional biological classification method,bacteria could grow in thionine and fuchsin dyes,A and M factors serum agglutination tests were positive,Bk2 phage lysis test was positive,but Tb and Wb phage lysis tests were negative;and the results of BSCP31-PCR of tested strain was 223 bp band same to Brucella;the results of AMOS-PCR was 731 bp band same to Brucella melitensis.Conclusion Conventional bio-typing test assisted with molecular techniques has confirmed that the isolated Brucella strain from sheep blood is Brucella melitensis type 3 in Jingyuan County Gansu Province.

Study on the classification of dominant pathogens related to febrile respiratory syndrome, based on the method of Bayes discriminant analysis / 中华流行病学杂志

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.

Study on seasonal characteristics and pathogenic distribution of influenza in Gansu province of China / 中华流行病学杂志

Objective To study the epidemiologic characteristics of influenza in Gansu province of China and to optimize the related vaccination program.Methods Weekly influenza surveillance data from the first week of 2010 to the fortieth week of 2016 were collected,in Gansu province.x2 test was used to compare the differences of nucleic acid positive rate and the virus types in the four seasons.Time series seasonal decomposition (TSSD) was used to explore seasonal patterns and characteristics of influenza epidemics in Gansu.Results 59 791 specimens were tested,with 8 501 positive for influenza virus and positive rates as 14.22％.Types A(H1N1)pdm09,A(H3N2) and type B were accounted for 98.76％ of all the positive specimens.Proportions of the positive rate of influenza virus appeared in spring,summer,autumn and winter were 15.12％,0.98％,4.02％ and 24.26％ respectively.The predominant type of virus in autumn and winter was A(H3N2),with B mainly in spring.Influenza in Gansu province showed typical single-peak type distribution,with epidemic peak appeared from December to next January.The type A(H3N2) related peak appeared the earliest,followed by A(H1N1)pdm09,with type B the latest.Conclusions Peaks and the duration of influenza seasonal epidemics were related to the types of dominant strains.Annual influenza vaccination campaigns should start in October,to provide effective protection during the epidemic period.

Drug resistance and dissemination of New Delhi metallo-β-lactamase 1 positive bacteria in a patient / 中华预防医学杂志

Objective@#The aim of this work was to report the surveillance and dissemination of NDM-1 positive bacteria in a patient and ward environment.@*Methods@#In 2010, during the therapy for a 51 years old patient, clinical and environmental samples were collected for carbapenem resistant bacterial culture, according to the clinical microbiological examination. Strains identification and antibiotic susceptibility were tested by VITEK Compact 2 system and E-test. The blaNDM-1 was detected by PCR and analyzed by sequencing. Plasmids containing blaNDM-1 were submitted to PFGE-S1 and Southern hybridization.@*Results@#During hospitalization from October 1st to November 4th, nine strains were isolated from blood, sputum, urine, fecal, and ward ground samples. The Klebsiella oxytoca, Raoultella planticola, and Acinetobacter baumannii were isolated from blood sample. The Klebsiella pneumonia and Acinetobacter baumannii were isolated from sputum sample. An Acinetobacter lwoffii was isolated from urine sample. An Escherichia coli was isolated from fecal sample. And the Acinetobacter lwoffii and Acinetobacter spp. were isolated from ward ground. Four strains were NDM-1 positive, which were Raoultella planticola (RpNDM1) isolated from blood, Escherichia coli (EcNDM1) isolated from fecal, Acinetobacter lwoffii (AlDNM1) and Acinetobacter spp. (AsNDM1) isolated from ward ground. Four NDM-1 positive strains were resistant to Piperacillin, Piperacillin tazobactam, Cefepime, Ceftriaxone, Ceftazidime, Imipenem, Meropenem, and Ertapenem. Southern hybridization revealed that blaNDM-1 were all located on plasmids in the four positive strains.@*Conclusion@#blaNDM-1 can transfer rapidly among different species, resulting in difficult to control and prevent. While isolating patient who is carrying NDM-1 positive strains, more attention should be paid to the disposal of patient's excreta, especially stool, should be paid more attention.

Early warning analysis of avian influenza virus in environmental samples in Gansu province, 2015 / 中华实验和临床病毒学杂志

Objective@#To understand the contamination status of avian influenza virus H5, H7, and H9 in environmental samples in Gansu province during 2015, and provide scientific guidance for the prevention and control of human infection with AIV in the province.@*Methods@#We detected the AIV nucleic acid of 2015 environmental samples with real-time PCR; the samples were collected from all of the monitoring points in the whole province, then we analyzed the result of environmental monitoring of pathogens in the province.@*Results@#The detection rates of FluA, H5, H7 and H9 were 19.90%, 0.05%, 0 and 19.65% respectively. The sample specific detection rate of FluA was the highest in wipe specimen of the board surface of slaughtering or placing poultry (31.09%) and the lowest in stool specimens (13.85%). FluA detection rate was the highest in December and the lowest in June and July(8.59% and 8.66%). The detection rate of Dingxi city and Longnan city of nucleic acid of avian influenza virus FluA and H9 were significantly higher than those in other cities in the province(χ2=4.523~88.059, P<0.05).@*Conclusions@#The main AIV pollution of the external environment in Gansu province in 2015 were the H9 subtype, and there was no H7N9 positive, we should strengthen the monitoring and early warning for avian influenza.

Epidemic and etiological characteristics of hand, foot and mouth disease in Gansu province during 2013—2015 / 中华实验和临床病毒学杂志

Objective@#To analyze the epidemiological and etiological characters of hand, foot and mouth disease ( HFMD ) in Gansu during 2013 to 2015 and provide evidence for the development of effective prevention and control measures.@*Methods@#The descriptive epidemiological analysis was used to analyze the data of HFMD, and the specimens were collected from hospitals to detect the pathogens by RT- PCR or Real-time RT-PCR. The nucleotide sequences of VP1 encoding region of virus strains were amplified by RT-PCR method, and determined and analyzed.@*Results@#Total of 29 934 HFMD cases were reported in Gansu from 2013 to 2015, including 81 severe cases and 2 deaths; the largest number occurred in Lanzhou was 7 053, accounting for 23.56% of the cases in the province. HFMD cases were mostly reported during May to July, accounted for 61.69% in total cases; the male to female ratio was 1.5: 1, and most cases were under the age of five and accounted for 83.02%. A total of 5 251 laboratory confirmed cases were reported, of which the number of cases caused by human enterovirus (HEV) were 2 972, the positive rate was 56.60%. Among the severe 81 cases, the positive rate of HEV was 67.90%, and both of the 2 death cases were infected by EV71. 341 strains of viruses were isolated, the genotyping of VP1 encoding region showed that all the 133 EV71 were C4a; among the 134 CVA16 isolates, 6 were B1a and 128 were B1b.@*Conclusions@#In Gansu province, there is a high infection rate of HFMD in children under the age of five, the proportion of other HEV is more and more, and the incidence is related to the difference of pathogens that showed alternant epidemic characteristics. CVA16 and EV71 viruses have the phenomenon of alternating.

Study on the classification of dominant pathogens related to febrile respiratory syndrome, based on the method of Bayes discriminant analysis / 中华流行病学杂志

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.

Study on seasonal characteristics and pathogenic distribution of influenza in Gansu province of China / 中华流行病学杂志

Objective To study the epidemiologic characteristics of influenza in Gansu province of China and to optimize the related vaccination program.Methods Weekly influenza surveillance data from the first week of 2010 to the fortieth week of 2016 were collected,in Gansu province.x2 test was used to compare the differences of nucleic acid positive rate and the virus types in the four seasons.Time series seasonal decomposition (TSSD) was used to explore seasonal patterns and characteristics of influenza epidemics in Gansu.Results 59 791 specimens were tested,with 8 501 positive for influenza virus and positive rates as 14.22％.Types A(H1N1)pdm09,A(H3N2) and type B were accounted for 98.76％ of all the positive specimens.Proportions of the positive rate of influenza virus appeared in spring,summer,autumn and winter were 15.12％,0.98％,4.02％ and 24.26％ respectively.The predominant type of virus in autumn and winter was A(H3N2),with B mainly in spring.Influenza in Gansu province showed typical single-peak type distribution,with epidemic peak appeared from December to next January.The type A(H3N2) related peak appeared the earliest,followed by A(H1N1)pdm09,with type B the latest.Conclusions Peaks and the duration of influenza seasonal epidemics were related to the types of dominant strains.Annual influenza vaccination campaigns should start in October,to provide effective protection during the epidemic period.

Study on early warning method for influenza epidemic in Gansu province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the appropriate early warning method for influenza epidemic in Gansu province.</p><p><b>METHODS</b>By using simple control chart, moving percentile method, exponential smoothing method and cumulative sum control chart method, the annual incidence data of influenza-like illness in Gansu province during 2014-2015 were analyzed, and the sensitivities, specificities, positive predictive values, Jorden indexes and Kappa values of the 4 methods were evaluated and compared.</p><p><b>RESULTS</b>The 2014-2015 seasonal influenza epidemic occurred in the fiftieth week of 2014 in Gansu, and the epidemic peak lasted for 6 weeks. Cumulative sum control chart method had the best early warning effect with the sensitivity of 66.67% and specificity of 93.48%.</p><p><b>CONCLUSION</b>It is feasible to use cumulative sum control chart method to give early warning of influenza epidemic in Gansu.</p>

Clinical characteristics of adult influenza inpatients in ten provinces in China and analysis of severe risk factors / 中华流行病学杂志

<p><b>OBJECTIVE</b>To identity the clinical characteristics and severe case risk factors for the adult inpatient cases confirmed of influenza monitored by the sentinel surveillance system for severe acute respiratory infection (SARI) inpatient cases in ten provinces in China.</p><p><b>METHODS</b>Epidemiology and clinical information surveys were conducted for adult cases (≥ 15 year old) consistent with SARI case definition, who were monitored by SARI sentinel hospitals in ten cities in China from December 2009 to June 2014, with their respiratory tract specimens collected for influenza RNA detection. Adult SARI cases were classified into influenza inpatient group and outpatient group by the detection outcomes, analyzing their demographic information, clinical and epidemiology characteristics respectively, in addition to risk factors for severe inpatient cases.</p><p><b>RESULTS</b>3 071 adult SARI cases were recruited from ten hospitals, including 240 (7.8%) cases of laboratory-confirmed influenza, most of them being A (H1N1) pdm2009 and A (H3N2) sub-types. Age M of the included influenza cases was 63 year old, 47.1% of them being ≥ 65 seniors. 144 (60.0%) cases of the influenza inpatients suffered from at least one chronic underlying condition, and the proportion of emphysema (7.9%) was higher than non-influenza inpatient cases (3.8%), being statistically significant (χ(2) = 3.963, P = 0.047). 19.4% of the women of childbearing age infected of influenza were in pregnancy, and only 1.1% of the 240 influenza cases had been vaccinated against influenza. The proportion of sore throat and dyspnea found among influenza inpatients was higher than inpatients without influenza. 17.4% of the influenza cases were accepted into ICU for treatment, with no statistical significance with non-influenza inpatient cases (P = 0.160). 23.1% of the influenza inpatients received an antiviral drug therapy, a figure higher than the non-influenza inpatient cases (4.8%) (P < 0.001). 41.5% of the inpatients developed complications, with the proportion of viral pneumonia significantly higher than the non-influenza inpatient cases (P < 0.001). Asthma (RR = 15.200, 95% CI: 1.157-199.633), immunosuppressive diseases (RR = 5.250, 95% CI: 1.255-21.960), pregnancy (RR = 21.000, 95% CI: 1.734-254.275), time interval from onset to admission less 7 days (RR = 1.673, 95% CI: 1.071-2.614) were identified as risk factors of severely-ill influenza cases.</p><p><b>CONCLUSION</b>It was found that adult influenza inpatients were mostly ≥ 65 year old seniors. The influenza vaccination rate among the influenza cases was very low, and antivirus drugs were used less than necessary. In this regard, influenza vaccination was recommended for high risk groups of pregnant women, seniors and chronic disease patients on annual basis, while influenza inpatients were advised to use antiviral drugs as early as possible.</p>