广州市2019年登革热确诊病例空间聚集性及登革病毒E基因进化特征分析

Spatial autocorrelation of dengue cases and molecular biological characteristics of envelope gene of dengue virus in Guangzhou,2019

目的:分析2019年广州市登革热流行情况,评估登革病毒4种血清型对流行的影响。方法:在传染病报告信息管理系统中收集2019年广州市登革热确诊病例信息,使用ArcGIS 10.2软件进行空间自相关性和聚集性分析,使用荧光定量PCR对血清标本进行核酸检测,将结果为阳性的血清标本进行病毒分离并测定E基因序列,用PhyML 3.1软件绘制基因进化树并分析。结果:2019年广州市共报告登革热确诊病例1655例,发病率11.10/10万,本地病例1382例,输入病例273例,发病具有空间聚集性,发现18个高-高聚集性街道,输入病例来源以东南亚国家(86.08%,235/273)和非洲国家(2.56%,7/273)为主。荧光定量PCR检测确诊病例血清标本749例,阳性率93.06%(697/749),分离毒株464株。同往年基因树相比,登革病毒未发现基因型的转换。登革病毒血清型1型仍然是广州市的优势毒株,血清型2型主要在白云区和荔湾区流行。结论:2019年广州市登革热疫情累及全市,范围向城乡接合部扩大和转移,应进一步重视城乡接合部的防控工作。加强来自东南亚和非洲国家的国境检疫。登革病毒血清型2型的流行和聚集性暴发风险不容忽视。多种血清型在广州市同时出现,提示需预防重症登革热的暴发和流行。

Objective Analyze epidemiological situation of dengue fever,and survey impacts of four serotypes dengue viruses in Guangzhou,2019.Methods Information of patients was collected in Notifiable Infectious Disease Report System(NIDRS).Spatial autocorrelation of dengue cases was evaluated using ArcGIS version 10.2.Serum samples were tested by real-time PCR.Virus strains were isolated from positive sera.Then E gene was sequenced.Phylogenetic trees were including PhyMLsoftwarev 3.1.Results A total of 1655 dengue cases,consisted of 1382 local cases and 273 imported cases,was confirmed in 2019.The incidence was 11.10 per 100000 dengue cases were autocorrelated in Guangzhou.There were 18 high-high clusters.Most of the imported dengue cases were imported from Southeast Asian countries(86.08%,235/273)and African countries(2.56%,7/273).Of 749 serum samples detected by real-time PCR,the positive rate was 93.06%(697/749).Four hundred and sixty-four dengue virus strains had been isolated in 2019.Compared with data from the genotype tree of the former years,no genotype shift was discovered.Serotype 1 was still predominant.Serotype 2 was the significant strain in Baiyun district and Liwan district.Conclusions Dengue fever was spreading all over Guangzhou in 2019.The suburban areas,which played a more critical role in causing the spread and outbreak of dengue fever,should be given more prominence.Inspection at ports should be enforced to prevent importing cases from African countries and Southeast Asian countries.The risk of serotype 2 cannot be overlooked.Four serotypes dengue viruses prevailed simultaneously in Guangzhou,which warns us to take precaution of severe dengue outbreaks.