2019年河南省北部地区登革热本地暴发疫情的分析

Analysis of the local dengue fever outbreak in the north of Henan Province in 2019

目的对引起濮阳市2019年登革热本地暴发疫情的分子流行病学及病原学特征进行分析,为河南省登革热防控举措提供数据支撑。方法收集所有疑似登革热病例的血液标本,检测登革病毒抗原、抗体及核酸,病毒核酸扩增E基因序列,测序并构建系统进化树。结果此次疫情共报告登革热本地病例61例,无死亡病例。登革病毒NS1抗原阳性44例,占比72.13%;登革病毒特异性IgM阳性38例,占比62.30%;登革病毒特异性IgG阳性16例,占比26.23%;登革核酸检测阳性34例,占比54.10%。分离得到登革病毒株10株,全部为登革病毒1型。通过E基因序列分析,与2019年柬埔寨输入河南驻马店的Henan201903株同属于一个分支,同源性最高。结论河南省本次疫情由登革病毒1型引起,输入来源与柬埔寨、新加坡、缅甸等东南亚国家相关,因此要加强东南亚归国人员入境监测工作。

Objective To provide data support for the prevention and control of dengue fever in Henan Province by analyzing the molecular epidemiological and etiological characteristics of dengue fever outbreaks in Puyang in 2019.Methods Blood samples were collected from all suspected cases of dengue fever.The antigen,antibody and nucleic acid of dengue virus(DENV)were detected.The E gene was amplified by viral nucleic acid extraction and sequenced.Phylogenetic tree was constructed to trace the source of infection.Results A total of 61 local cases of dengue fever were reported,and no deaths were reported.Among them,4 cases(72.13%)were positive for DENV NS1 antigen;16(26.23%)cases were positive for specific IgM;38(62.30%)cases were positive for specific IgG;34 cases(54.10%)were positive for dengue nucleic acid testing.Ten dengue virus strains were isolated,all of which were dengue virus type 1(DENV-1).Sequence analysis of E gene suggested it belonged to the same clade as Henan201903 strain imported from Cambodia to Zhumadian,Henan in 2019,with the highest homology.Conclusions The dengue fever epidemic in Henan Province was caused by DENV-1,which might be improted from Cambodia,Singapore,Myanmar and other Southeast Asian countries.Therefore,the surveillance of DENV in people returning from Southeast Asia should be strengthened.