热带病与寄生虫学

热带病与寄生虫学 ›› 2022, Vol. 20 ›› Issue (4): 215-220.

• 防治研究 • 上一篇    下一篇

2019年昆明市输入性登革热病例流行病学和病原学特征分析

王雪菲1，田荣2，陈志辉2，杨明东1，郭晓芳1   

  1. 1. 云南省寄生虫病防治所，云南省虫媒传染病防控重点实验室，云南普洱665000； 2. 昆明市疾病预防控制中心
  • 收稿日期:2022-03-18 出版日期:2022-08-20 发布日期:2022-08-31
  • 作者简介:王雪菲，女，硕士，医师，研究方向：虫媒病毒性疾病防控。E-mail：yipdwxf@163.com 田荣，男，硕士，主管医师，研究方向：自然疫源性疾病与虫媒病毒性疾病控制。E-mail：dly_feiteng@163.com 王雪菲、田荣同为第一作者
  • 基金资助:
    国家自然科学基金项目（81560548）

Analysis on the epidemiological and etiological characteristics of imported dengue fever cases in Kunming in 2019

WANG Xue-fei1, TIAN Rong2, CHEN Zhi-hui2, YANG Ming-dong1, GUO Xiao-fang1   

  1. 1. Yunnan Provincial Institute of Parasitic Diseases, Yunnan Provincial Key Laboratory of Vector-borne Infectious Diseases Control and Research, Pu'er City 665000, Yunnan Province, China; 
    2. Kunming Center for Disease Control and Prevention
  • Received:2022-03-18 Online:2022-08-20 Published:2022-08-31

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摘要： 目的 分析云南省昆明市2019年输入性登革热病例流行病学及病原学特征，为登革热防控提供决策依据。方法 按《全国登革热监测方案》收集2019年昆明市输入性登革热病例信息；采集1—6月部分输入性病例血清，采用实时荧光RT-PCR对血清样本进行登革病毒（dengue virus, DENV）血清型分型，扩增病毒E基因序列并进行系统进化分析。结果 2019年昆明市共报告输入性登革热病例400例，境外输入297例（占74.25%），主要来自柬埔寨（187例）、缅甸（38例）和老挝（28例）；境内输入99例（占24.75%），主要来自云南省西双版纳州（93例）。全年均有病例输入，5—10月为输入高峰。男女比例为2.01∶1；各年龄组均有病例报告，以青壮年为主，20～50岁病例占84.25%；职业主要为家务及待业人员（占19.50%）、商业服务人员（占14.00%）、干部职员（占13.00%）、农民（占11.50%）和工人（占10.75%）。1—6月共采集60份输入性登革热病例血清样本，来源国为柬埔寨（49例）、老挝（1例）、缅甸（3例）、越南（3例）、泰国（1例）和非洲地区（3例），共检出29例DENV-1型和5例DENV-2型，输入地为柬埔寨（28例DENV-1型，4例DENV-2型）、越南（1例DENV-2型）和泰国（1例DENV-1型）。从34例DENV型样本中扩增得到8条E基因序列，其中DENV-1型 6条、DENV-2型 2条，输入地分别为柬埔寨和泰国。E基因序列系统进化分析表明，6株DENV-1型均属基因Ⅰ型，相似性为96.63%～100.00%。其中，1株（输入地为泰国）和2019年泰国流行株高度同源；其余5株（输入地为柬埔寨）分别与2019年广东柬埔寨输入株、2019年柬埔寨株、2019年老挝株和2019年南昌株高度同源。2株DENV-2型（输入地为柬埔寨）均属Asian Ⅰ基因型，相似性为99.73%，均与2019年广东柬埔寨输入株高度同源。结论 2019年昆明市输入性登革热病例来源地主要为东南亚国家，输入性登革热病例病毒株与东南亚流行株和输入株高度同源，提示应提高输入性病例的发现和报告能力，预防由输入性病例引起的本地暴发。

关键词: 登革热, 输入性病例, 流行特征, E基因, 进化分析, 昆明市

Abstract: Objective To analyze the epidemiological and etiological characteristics of imported dengue fever cases in Kunming City in 2019 for evidences in planning prevention and control measures for this infection. Methods The epidemiological information was collected from the imported dengue fever cases in Kunming City in 2019 according to the National Dengue Surveillance Program in China. Serum samples were obtained from part of the imported dengue fever cases reported between January and June of 2019, and subjected to serotyping of the dengue virus (DENV) by RT-PCR. In addition, E gene sequence of the virus was amplified for phylogenetic analysis. Results A total of 400 imported cases were reported in Kunming in 2019, in which 297 (74.25%) were imported from foreign countries such as Cambodia (187 cases), Myanmar (38 cases) and Laos (28 cases). Ninety-nine cases (24.75%) were from mainland China, and most of them (93 cases) were from Xishuangbanna of Yunnan Province. The cases were reported all year round, and peaked from May to October of the year. The male to female ratio was 2.01∶1. The cases were distributed in every age group, yet most were young adults aged from 20 to 50 years (84.25%). The occupation of the reported cases was associated with house-workers and currently unemployed (19.5%), traders (14%), government staffs (13%), famers (11.5%) and workers (10.75%). Between January and June of 2019, a total of 60 aliquots of serum samples were collected from the imported dengue fever cases that were from Cambodia (n=49), Laos (n=1), Myanmar (n=3), Vietnam (n=3), Thailand (n=1) and African countries (n=3). Of the 60 samples, 29 and 5 were respectively positive for DENV-1 and DENV-2. The cases imported from Cambodia were involved in DENV-1 (n=28) and DENV-2 (n=4), and DENV-2 and DENV-1 were seen in one case from Vietnam and another one from Thailand. Eight E gene sequences of DENV were amplified from 34 samples, 6 of which were DENV-1 from Cambodia, and 2 of which were DENV-2 from and Thailand. Phylogenetic tree analysis showed that 6 strains of DENV-1 belonged to genotype Ⅰ, and nucleotide sequence identities among the 6 sequences were 96.63% -100.00%. Of six sequences, one (imported from Thailand) was highly homologous with the epidemic strained identified in 2019 in Thailand, and the other 5 sequences (imported from Cambodia) had the highest homology with the strain reported in Guangdong (imported from Cambodia in 2019) and in Nanchang in 2019 (imported from Cambodia and Laos). DENV-2 sequences amplified from two strains of the cases imported from Cambodia belonged to Asian Ⅰ genotype, with a nucleotide sequence identity being 99.73%. Both strains were in high homology with those reported in Guangdong imported from Cambodia in 2019. Conclusion In 2019, most dengue cases in Kunming City were imported from Southeast Asian countries, and the imported dengue virus strains were highly homologous with the strains epidemic in and imported from Southeast Asian countries. The results suggest that it is necessary to improve early detection and report of the imported cases in order to prevent local outbreaks caused by imported cases. 

Key words: Dengue fever, Imported cases, Epidemiological characteristics, E gene, Phylogenetic analysis, Kunming City

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