河南省22例输入性登革热病例特征及基因分型

Epidemiological and genotypic analysis of 22 imported dengue fever cases in Henan Province

目的分析22例输入性登革热病例的流行病学特征及登革病毒(DENV)E基因分子特征,为疾病诊治和预防提供依据。方法对2017—2022年于河南省传染病医院住院的登革热确诊病例进行回顾性调查,采集患者血液标本,采用荧光PCR进行DENV核酸检测。核酸检测阳性标本的RNA反转录成cDNA,再利用PCR扩增E基因序列,进行基因测序拼接后,进行同源性比对和系统进化分析。结果22例登革热确诊病例中,其中20例为境外输入病例,来自东南亚(17例,77.3%)和非洲(3例,13.7%),其余2例分别来自广东和云南。男性18例,年龄以18~50岁为主(18例,81.8%);14例(63.6%)发病时间集中在7—11月。临床症状以发热(22例,100.0%)、头痛(13例,59.1%)、肌肉/关节痛(8例,36.4%)。DENV核酸阳性20例(90.9%),成功获得17条DENV E基因序列。同源性和系统进化分析表明,11株属于DENV-1Ⅰ型E基因型,与柬埔寨、越南、马来西亚、中国广东、中国云南等地的流行毒株具有96.6%~100.0%核苷酸序列间同源性;4株和1株毒株中分别鉴定出DENV-2全球型及亚洲Ⅱ型,E基因核苷酸序列间的同源性为93.3%~99.9%,与斯里兰卡、马来西亚、印度等地的流行毒株距离最近;1株DENV-3Ⅲ型,在基因上与泰国流行毒株的距离最近。结论河南省输入性登革热病例主要来自东南亚地区,流行型别以DENV-1为主。应加强针对性的监测和防控措施,以遏制输入性登革热的潜在的本地传播。

Objective To analyze the epidemiological characteristics of 22 imported dengue fever cases and the molecular characteristics of dengue virus(DENV)E gene,so as to provide data for the diagnosis,treatment and prevention of DENV.Methods A retrospective investigation was conducted on inpatients diagnosed with dengue fever at Henan Infectious Diseases Hospitals from 2017 to 2022.Blood samples were collected for DENV nucleic acid detection using real-time RT-PCR.The RNA of positive samples was reversely transcribed into cDNA,followed by amplification of the E gene and subsequent sequencing and assembly.Homology and phylogenetic analyses were performed on the obtained sequences.Results A total of 22 dengue fever cases were confirmed,with 20 being imported from Southeast Asia(17/22,77.3%)and Africa(3/22,13.7%),and the remaining 2 cases from Guangdong and Yunnan,China respectively.18 patients′(81.8%)age ranged from 18 to 50 years old,and 18 male cases were male.Most cases(14 cases,63.6%)were reported between July and November.Clinical manifestations included fever(22 cases,100.0%),headache(13 cases,59.1%)and myalgia/arthralgia(8 cases,36.4%).DENV RNA was detected in 20 cases(90.9%).17 DENV E gene sequences were successfully obtained and analyzed.Phylogenetic and homology analyses revealed that 11 strains belonged to DENV-1 genotype Ⅰ,showing 96.6%-100.0%homology and clustering with strains from Cambodia,Vietnam,Malaysia,Guangdong,and Yunnan.DENV-2 genotypes Cosmopolitan and Asian Ⅱ were identified in four and one strains,respectively,with an homology of 93.3%-99.9%and closest genetic affinity to strains from Sri Lanka,Malaysia,and India strains.One strain was classified as DENV-3 genotype Ⅲ,genetically closest to a Thailand strain.Conclusions Imported dengue fever cases in Henan Province predominantly originated from Southeast Asia,with a predominance of DENV-1 genotype.Enhanced targeted surveillance and prevention measures are warranted to curb potential local transmission of imported dengue fever.