2015-2017年汕头市登革病毒分子流行病学研究

目的 为了解汕头市登革病毒的分子特征与病毒的来源和传播途径，对汕头市登革病毒进行分子监测，并对登革病毒进行分子流行病学研究。方法 利用2015-2017年间采集的174例登革热疑似患者的血清样本；对样本进行登革病毒IgM和IgG、NS1抗原检测；采用实时rt-PCR进行登革病毒RNA检测和血清分型；PCR扩增病毒的包膜(E)基因并进行序列测定；对序列进行系统发育分析，以推测病毒的基因型、起源和传播。结果 174例登革热疑似病例中，59例(33.9%)检出登革病毒感染。血清型以DENV-2为主(15例，占51.7%)，其次为DENV-1(12例，占41.4%)，DENV-3和DENV-4各1例；DENV-1型毒株的基因型有I型和IV型，DENV-2型毒株均属于cosmopolitan基因型；序列分析表明，汕头菌株与东南亚国家分离的菌株关系密切。结论 本研究揭示了汕头市登革病毒的血清型和基因型的分布，血清型以DENV-2为主，基因型以cosmopolitan为主；推测汕头登革热流行的病毒株多来源于市外，而非本地流行；病毒毒株的主要起源地为东南亚国家。

Molecular epidemiology of Dengue virus,Shantou City, 2015-2017

To understand the molecular character，origin and transmission route of DENV in Shantou City，and toperform surveillance and molecular epidemiological study of Dengue virus. Methods Serum samples from 174 dengue －suspected patients were collected from 2015 to 2017. Dengue infection data were obtained using anti － dengue IgM and IgGtests，dengue NS1 antigen test，as well as ＲNA detection. Serotyping was performed using real － time ＲT － PCＲ. Viruses wereisolated and the envelope ( E) gene was sequenced. Phylogenetic analysis was performed to speculate the genotype，origin，andtransmission of the viruses. Ｒesults Dengue infection was detected in 59 ( 33. 9% ) of 174 suspected cases. Serotypingrevealed the predominance of DENV － 2 ( 15 cases，51. 7% ) ，followed by DENV － 1 ( 12 cases，41. 4% ) ，while DENV － 3and DENV － 4 were each detected in only one case respectively. Co － circulation of genotype I and IV of was observed in DENV－ 1 strains while DENV － 2 strains all belonged to the Cosmopolitan genotype. Sequence analysis showed that Shantou strainsdisplayed close relation with the strains isolated in Southeast Asian countries. Conclusion Distributions of DENV serotypesand genotypes in Shantou City are revealed and DENV － 2 ( cosmopolitan) as the predominant DENV serotype ( genotype) isobserved. The Dengue endemic in Shantou City tends to be exotic infection rather than local circulation and the strains areorigin from Southeast Asian countries.