| Dengue fever(DF)is a natural epidemic disease caused by dengue virus(DENV)transmitted by Aedes mosquitoes.The global epidemic of DF is becoming more and more serious,currently becoming an increasingly serious global public health problem.In recent10 years,DF outbreaks occurred in Guangdong Province and Yunnan Province,of which 8genotypes from 4 DENV serotypes were found in Yunnan Province.In Ruili City of Yunnan Province,the first DF case was imported from Myanmar in 2006 and its first local infectious DF case was found in 2008,meanwhile,a large-scale local infectious DF outbreak was occurred in 2013,and since then,its local infectious DF outbreak has occurred every year.Although the serotypes of DENV were various in Ruili City from 2013 to 2017,DENV-1 was still main DENV serotype.This study aimed to investigate the genotypes and clinical features of DENV in Ruili City from 2014 to 2017,which it provides evidences for formulating local effective strategies of DF treatment and prevention.?Objective?To explore the serotypes,genotypes and clinical characteristics of DENV in Ruili City,Yunnan Province from 2014 to 2017,providing local evidences for formulating effective strategies of DF treatment and prevention.?Methods?Viral RNA was extracted from DF serum samples at the acute stage in Ruili from 2014 to 2017(storing at the refergeration of-80? in the laboratory of Yunnan institute of parasitic disease),and DENV was tested by AgPath-ID One-step Realtime RT-PCR;DENV was isolated by vero cell cultivation,then sequencing C/PrM and E genes Comparing and analyzing their nucleotide similaritiese by bioinformatics softwares of SeqMan,Mega5.0,Cluster X1.83 and Megalign Patients hospitalized and diagnosed as DF were selected as the study objects in the People's Hospital of Ruili City from 2014 to 2017,by collecting their main clinical features datum related DF,including their clinical symptoms,signs and laboratory biochemical indicators,and above datum were analyzed by using Microsoft Excel(2007)software and SPSS 22.0 software.?Results?A total of 429 acute stage samples were collected from DF patients in Ruili City from2014 to 2017,and 4 serotypes of DENV were found;of those there were 305 DENV-1(71.10%,305/429),77 DENV-2(17.95%,77/429),28 DENV-3(6.53%,28/429)and 19DENV-4(4.43%,19/429);total of 1 sample was found to be the secondary infection(Myanmar imported case infected DENV-1 in 2014 and reinfected DENV-4 in the overseas in 2017);125 strains C/PrM gene sequences were detected,of those 100 strains DENV-1were genotype I(Genotype I,G-I,9 strains DENV-2 were Asian genotype I,8 strains DENV-3 strains were genotype I and 8 strains DENV-4 strains were genotype I;total of 33 strains E genes of DENV-1 were sequenced,and all of them belonged to G-I.Of those 15 strains DENV-1 belonged to local infected DF cases(i.e 2 strains in 2014,3 strains in 2016,10 strains in 2017),and18 strains DENV-1 were infected from Myanmar(i.e 6 strains in2014,4 strains in 2015,4 strains in 2016,4 strains in 2017),by comparing their E-gene evolutionary trees,both local infected DENV-1 and imported from Myanmar were distributed in the same branch,their nucleotide homologies were higher at 94.6%-99.5%;and their nucleotide homologies were 94.8%-99.3% with that from Thailand(JQ993198)and 94.0%-99.4% with that fromMyanmar(AY726549?AY726551).Total of 150 DF cases from Ruili 4 DENV serotypes were anlazed by the clinic features from 2014 to 2017,their rates of fever were 90.67%(136/150),muscle soreness were 78.67%(118/150),headache were 75.33%(113/150)and rash were 37.33%(57/150),their reduction rates of white blood cells(WBC),blood platelet(PLT),hematocrystallin(HGB),neutrophil absolute value(NEU),lymphocyte(LYM)were 67.33%,51.33%,7.33%,76%,38.67% respectively,and their rising rates of alanine aminotransferase(ALT),aspartate aminotransferase(AST),Glutamyltrans-ferase(GGT),lactate dehydrogenase(LDH),creatine phosphokinase(CK),Creatine Kinase Isoenzyme-MB(CK-MB)were 61.33%,66.67%,51.33%,54.67%,29.33%,13.33% respectively.Of those,the incidence of DENV-1 for rash and bleeding tendency were more significant than the other 3 DENV serotypes,and the headache incidence of DENV-2 was higher than the other 3 DENV serotypes;more important for DENV-1,its reduction rates of WBC and PLT were 64% and 58.67% respectively,the rising rate of ALT,AST and myocardial enzymes were 73.44%,74.67% and 74.67% respectively,as well as liver function impaired rate73.33%.?Conclusion?There were 4 genotypes from 4 DENV serotypes in Ruili City from 2014 to 2017,mained on DENV-1 G-I,and local DENV-1 were more related with Myanmar and Thainland DENV-1,which above results were suggested that both DENV gene types and serothpes were complex in Ruili City,and local DENV-1 was come from that from Myanmar and Thailand;all of 4 DENV serotypes clinic features were mained on the ligh type,but those of DENV-1 were more serious than those of the other 3 DENV serotypes.Above results were suggest that local healthy department should be strengthened in monitoring of DENV serotypes,genotypes and clinical features in case preventing the occurrence of severe or fatal cases. |
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