| Obejective To analyze the epidemiology characteristics of reported measles cases in China during 2014 and provide evidence for measles elimilation. To analyze and study the spatial distribution rule of measles prevalence in China, understand the spatial distribution characteristics and spatial autocorrelation among adjacent basic units(province) and explore hot spots. To study the genetic characterization of wild-type measles Viruses in China during 2014 Which provided scientific evidences for controling and preventing measles epidemic and measles elimilation. To study the genetic characterization and amino acid mutation of hemagglutinin protein of different genotypes of wild type measles Viruses isolated in 2013 and 2014,in China.Methods Analyze measles epidemiology data with descriptive epidemiology. First,ArcGis software import provinces basic unit of geographic data, with shp format Second,property sheet connected related external excel data table through geographical administrative code, and imported cases, incidence analysis indicators;Third, exported the layer all elements;Last,used Geoda software to create the distance weight matrix, and analyzed spatial autocorrelation of adjacent units,using single variable,for example,reported cases or incidence. Use SatScan software scan to explore hot spots,based on geographical unit, the day as the unit of time, space-time scan, exploring the hot spots which basic geographical unit was city and time unit day. Analyze measles etiology routine monitoring data, according to The 450 nucleotide sequence of CooH temlinal of nucleoprotein(N)of gene of these wild-type viruses which were amplified by RT-PCR and and the productions coming from PCR were directly sequenced. Select 29 Hla sub-genotype strains with spacial and temporal representative and imported genotypes including B3,D8,D9 and G3,then use MEGA5.0 to conduct Phylogentic analysis and diversity analysis with 31 reference strains including the WHO recommended the 26 strains of A sequence and Shanghai-191-G genotype strains and 4 strains China H1 genotype based on N gene carboxyl terminal 450 bp nucleotide sequence.So that to understand the national measles virus molecular epidemiological characteristics during 2014. Four genotype isolates of H1, D8, D9 and B3 measles viruses were selected,sent by Provincial Measles Laboratories,which caused measles epdemic or outbreak in China mainland in 2013 and 2014.The H1a sub-genotype is the endemic genotype throughout China,while the D8,D9 and B3 genotypes are imported.After extracting RNA from measles isolates, complete coding regions of hemagglutinin(1854nt) were amplified by RT-PCR and sequenced. Alignmented four strains of this study with 23 representative strains of H1a,D8,D9 and B3 genotypes and 2 Chinese vaccineStrains ShangHi-191 (s191) and Changchun-47 (C47) which submitted to GenBank, phylogenetic analysis and the diversity were done by MEGA version 5.0. Results ?The number of reported measles cases is 52637 during 2014 and the measles reported incidence is 3.88/10, increased significantly by 90.4%,compared with 2013 (27646 cases, the incidence of 2.04/10).2014 adult measles cases constituent ratio rose,while the constituent ratio of young age group(15 years) reduced accordingly compared with 2013. the incidence ang number of cases of 12 provinces reduced from 2013 to 2014, among them,hunan, anhui and Yunnan reduced most,respectively 4.28,2.89 and 2.11 per million.While incidence and reported cases of 21 provinces rose, among which liaoning province, tianjin, Inner Mongolia autonomous region rose most respectively 19.26,16.35 and 12.39 per million. ? History of immune monitoring, ingredients of measles vaccine inoculation history included 0,1,2,3 or higher doses,cases with certain measles vaccine immunization history (including 1,2,3 or more doses) is 5629 made up 10.1% of total ceses. The global moran'I values and p values of the total and adults reported maesles cases number were respectively 0.1493 and 0.0212 and 0.1493 and 0.0212, with statistical significance results at the level of a=0.05;While less than 8 months infants global Moran's I values is 0.1012, p value is 0.5725,and the number of cases less than 8 months in China had no spacial autocorrelation, but the results of local Moran's I analysis revealed that the autocorrelation type of liaoning province was high-high,that is,Liaoning province had positive spacial autocorrelation with its adjacent provinces,while zhejiang province had low-low spatial autocorrelation.The reported incidence of spatial autocorrelation analysis showed that the result of global Moran's I values is 0.2848, the P value is 0.000069, that is, the reported national incidence had positive spacial autocorrelation. The results of hot spots exploring is that the first cluster located in Beijing, tianjin, jilin, liaoning and Inner Mongolia and others in the southwest and northwest regions,and that some hot spots existed in hunan province. The total number of measles virus strains with N carboxyl terminal 450 bp nucleotide sequenceis 4938,among which 4891 strains were H1a sub-genotype,accounting for 99.03%,10 strains of B3 genotype, 3 strains of D8,9 strains of D9,1 strain of G3.The number of Beijing monitoring measles strain was 1279, including 1271 Hla,2 D8,1 B3, and 5 strains of VAC.The nucleotide sequence homology of 29 representatives of H1a sub-genotype based on the N gene carboxyl terminal 450 bp sequence was 96.1%?99.8%, and number of nucleotide differences between 1 and 18, amino acid homology was 99.0%-99.8, the amino acids difference was 1?2.29 strains sequence compared with S191,89.2%? 91.9% nucleotide homology (36?48), amino acid homology was 98.5%?98.7%(2? 3);And compared with Chin9322/Hla nucleotide homology was 97.3%?98.9%(5? 12), amino acid homology was 99.2%?99.5%(1?2);Compared with Chin9475/Hlb nucleotide homology was 95.1%?96.8%(14 to 22), amino acid homology was 98.8%-99.1%. The homology of H gene nucleotide sequence and amino acid between the four genotype measles virus strains including H1,B3,D8,D9 and A genotype strains were respectively 94.2%-96.7% and 95.4%-96.7% and there were 20-28 amino acids difference between them; And the homology of H gene nucleotide sequence between Beijingl4-l(H1a) and A genotype vaccine strains was 97.7%-98.2%.The N-glycosylation site in 240th was losen because of mutation Conclusion The number and incidence of reported measles cases significantly increased,compared witn 2013.And constituent ratio of adult measles cases rose, while younger age group relatively reduced.During the measles elimilation statge,it's of great importance to stength routine vaccination in the whole nation and supplementary immunization in the areas with high incidence. There are multiple clusters in the whole country for reported Measles cases in 2014, north China, northeast, southwest, northwest and other regions The number and incidence of reported measles cases had significantly positive spacial autocorrelation in the national level,while the result of global moran's I of number of cases of less than 8 months had no statistically significant autocorrelation;Each local spatial autocorrelation analysis indicators(including the total number of reported cases, adult reported cases number and incidence of each group) indicated high-high spatial autocorrelation mainly existed in hebei, liaoning and jilin provinces,while low-low spatial autocorrelation relations mainly in zhejiang and sichuan province.So alliance among provinces to prevent and control measles epidemic is essential during measles elimilation. The number of wild-type strains large increased compared with 2013,and the epidemic resulted from imported genotype,including B3,D8,D9 and G3 was serious.Hla sub-genotype was dominant.SO prevention and control Hla and imported measles genotypes is one of the important topics to eliminate measles in China. The homology of H gene nucleotide sequence and amino acid between the four genotype measles virus strains including H1,B3,D8,D9 and A genotype strains were high,and the Chinese vaccine can effectively prevent infection caused by Hla sub-genotype,D8,D9 and B3 imported genotypes virus strains. |
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