湖南省2018年登革热本地暴发流行病学和病毒分子特征分析

目的 对湖南省2018年登革热本地暴发疫情进行流行病学及病原学特征研究。方法 对报告的8例疑似登革热病例进行实验室诊断,对病例密切接触者搜索出的186例疑似登革热病例和发热病例开展病原学监测,应用C6/36细胞对病例急性期血清开展病毒分离,对15株登革病毒株E基因测序,分析病毒的血清型别和基因亚型,构建系统发生树,分析可能的传播来源。在疫点开展蚊媒密度应急监测和健康人群回顾性血清流行病学调查。结果 8例疑似病例血清标本,6例登革病毒核酸阳性,4例登革病毒NS1抗原阳性。186例疑似登革热病例,96例病原学检测结果阳性,分离到登革病毒株64株,经鉴定全部为登革病毒2型全球型,来源于广东和浙江省的可能性较大。应急蚊媒密度监测,疫点布雷图指数最高达65,具有极高的登革热传播风险。回顾性调查377名健康人群进行登革热抗体水平监测,IgG抗体阳性率为0.53%（2/377）。结论 现场流行病学调查和分子遗传分析提示,湖南省2018年本地暴发疫情由输入性病例引起,由单一的登革病毒2型全球型引起。     

一起输入性登革热暴发疫情流行病学调查

目的了解2013年禹州市登革热疫情发生情况及流行特征。方法查阅禹州市登革热暴发疫情处置资料及蚊媒监测资料对2013年禹州市登革热暴发疫情进行描述性流行病学分析。结果 2013年禹州市共报告登革热病例29例,发病率为2.55/10万,无死亡病例。地区分布于神镇苗家湾村;流行时间集中于9月份;男女性别发病数之比为1:1.27;年龄分布于40至69岁人群,占总病例数的55.17%;临床表现以轻型为主;实验室检测显示,流行株为登革病毒Ⅲ型。结论 2013年禹州市神镇苗家湾村登革热疫情为输入性病例引起本地感染的一起暴发疫情。依靠群众,大力开展宣传教育和快速杀灭成蚊和消除蚊媒孳生地是控制疫情的关键。另外,应开展持续的媒介监测,为今后防控登革热疫情提供有力保障。     

珠海市2007年登革热流行病学分析

目的分析珠海市2007年登革热疫情流行病学特征及流行因素,为今后制定登革热防控措施提供科学依据。方法收集珠海市传染病疫情监测和报告信息系统资料及流行病学个案调查、现场专题调查、住院病历等资料,采用描述性流行病学方法进行统计分析。采集相关标本进行登革病毒病原学检测。结果2007年珠海市共报告登革热病例132例,其中从澳门输入1例,本地感染131例,发病率为9.92/10万;临床表现以典型轻型为主,无死亡病例;病例集中分布在香洲区城乡结合部,东坑社区是主要暴发点;疫情始于8月13日,持续76 d,发病高峰在8月30日至9月6日;病例男女性别比为1.2∶1,年龄以20~39岁年龄组为主,占51.5%(68/132),职业以工人、家务及待业和学生为主。实验室检测显示,疫情流行株为登革病毒1型,输入病例病毒株为登革病毒2型。暴发点社区人群登革病毒感染率为7.0%。结论2007年珠海市登革热疫情呈局部暴发,为输入性病例引起本地感染的暴发疫情。开展持续的媒介监测,建立实验室支持的主动监测系统是有效的防控措施。     

2019年珠海市登革病毒流行情况及E基因演化分析

目的 通过对2019年珠海市登革热流行病学数据及及登革病毒包膜蛋白基因（E基因）序列进行分析,了解珠海市登革热流行规律和病毒遗传进化特点。方法 2019年珠海疾病预防控制中心采集登革热临床诊断病例的血液标本,对病例进行流行病学调查,磁珠法提取病毒核酸,用Real-time RT-PCR进行检测,阳性标本用RT-PCR扩增E基因并进行测序分型获得的基因序列,采用MEGA6.0软件进行系统进化分析。结果 共收集登革热临床诊断病例185例,实验室诊断病例99例,实验室诊断病例较2018年同期增长154%。其中输入性病例53例,本地感染病例46例,男性61例,女性38例,进入9月份本地感染病例增多,以散发状态为主,其中本地暴发疫情2起;75例成功测序,以DENV-1型为主,占88.00%,全部属于基因Ⅰ亚型,分布在3个不同分支上,分别与2017年越南、2015柬埔寨、2014年马来西亚、新加坡,2012、2014年斯里兰卡等流行株高度同源;DENV-2和DENV-3病例均为输入病例。结论 珠海市登革热主要由东南亚输入,极易发生输入性病例引起本地暴发流行,定期对流行的登革病毒进行序列分析有利于分析该病毒的基因进化方向。     

一起输入性登革热疫情调查与处置

目的调查一起输入性登革热疫情的流行病学特点及媒介伊蚊种类、密度,为制定登革热防治策略提供依据。方法采用个案调查表对2例登革热病例进行流行病学调查,酶联免疫吸附剂测定法对病例血液标本进行IgM、IgG抗体检测,布雷图指数法和双层叠帐法对媒介伊蚊密度进行应急监测;清理蚊媒孳生地,开展蚊媒消杀。结果 2例女性登革热病例,发病前刚从马尔代夫旅游归来,均为登革病毒通用型核酸阳性,确定为输入性病例。经病例主动搜索、清理蚊媒孳生环境、快速杀蚊,未发生二代病例。结论这是一起境外输入性登革热疫情,各部门密切配合,未发生疫情扩散。防控的关键是蚊媒孳生环境的清理和成蚊的快速杀灭。     

河源市某建筑工地一起登革热暴发疫情分析

目的调查广东省河源市某建筑工地一起登革热暴发疫情,探讨其流行病学特征和暴发原因,为登革热疫情科学防控提供参考。方法对疫点开展病例筛查和蚊媒调查,采集可疑病例血清,用ELISA方法检测特异性抗体,用RT-PCR方法进行登革病毒核酸检测和分型。使用描述性流行病学方法对调查资料进行分析。结果该起疫情从首例至末例的时间跨度为51 d,共发生病例32例,均为轻症无死亡。32例病例中男性25例、女性7例,年龄15～64岁,登革病毒核酸检测均为阳性,登革病毒Ⅰ型阳性14例。首次伊蚊幼虫密度监测核心区符合防控要求的为11个,占64.71%;警戒区符合防控要求的为5个,占41.67%;监测区符合防控要求的为11个,占52.38%。采取控制措施后10 d,媒介BI值下降至5以下,疫情得以控制。结论本次疫情由登革病毒Ⅰ型引发,首发病例未能及时发现和疫点地区蚊媒密度较高可能是引起疫情暴发的主要原因。登革热流行区应加强疫情和蚊媒监测,做好预警和灭蚊防蚊工作,预防控制暴发疫情的发生。     

广东省1990—1998年登革热流行病学监测分析

为了预防登革热的暴发流行,于1996 年4 月～1998年12 月开展了登革热的流行病学监测,根据以往发生过登革热流行的疫情分析,选择广东省3 个监测点,收集血标本95 份及蚊媒标本6000 余只分别作病原分离,并进一步采用单克隆抗体间接免疫荧光试验和RT- PCR 鉴定;采集监测点健康人血标本1025 份应用间接免疫荧光试验作抗体水平调查。3 个监测点上收集的发热待查患者和蚊媒标本均未能分离出登革病毒。蚊媒监测结果提示:布雷图指数大大超过有效控制指标5 ;全年大部分时间布雷图指数均超过20 以上;血清学调查表明:健康人群抗体水平逐年下降;因此存在登革热暴发流行的潜在危险     

2010年广州市登革热疫情监测结果分析

目的对广州市2010年登革热疫情的流行病学特征进行描述性分析,为今后广州市登革热预防控制工作的开展提供参考依据。方法采用描述性流行病学分析方法,对广州市登革热疫情监测与报告信息系统、实验室监测信息系统、现场调查报告、疫情简报等数据信息进行统计与分析。结果广州市2010年共报告登革热病例81例,其中本地感染病例59例,输入性病例22例,累计发病率为1．57／10万,无死亡病例;疫情涉及全市8个区26个行政街（镇）。检测可疑登革热发热患者血清标本1879人份,其中阳性139人份,阳性率为7．40％;分离到登革病毒29株,其中登革病毒Ⅰ型7株、Ⅱ型2株、Ⅲ型6株、Ⅳ型14株。蚊媒监测结果显示,蚊媒密度在6—10月份达到高峰,布雷图指数（BI）达4．02～6．40,与登革热疫情流行高峰相一致。结论2010年广州市登革热流行总体上呈现出中等强度、多点散发的流行态势,发病数较2009年明显增多,与广州市历年来登革热流行规律基本一致,属于发病规模较小的登革热暴发年份。     

登革病毒实验室诊断方法研究进展

目前登革病毒(dengue virus, DENV)已被世界卫生组织视为热带及亚热带地区的重大公共卫生问题。近年来全球范围内登革热疫情频发, 有愈演愈烈的趋势。仅2019年已在菲律宾、泰国、孟加拉国、缅甸及中国重庆市暴发了不同程度的登革热疫情。DENV的实验室诊断方法对于登革疫情的防控意义重大。为此本文对现阶段DENV实验室诊断方法及策略进行综述。通过回顾以往传统性诊断方法, 展望新兴的诊断策略, 为登革疫情暴发时选择合适的实验室诊断方案提供参考。     

东莞市一起Ⅳ型登革热暴发疫情流行病学调查分析及处置

目的 对2016年东莞市某街道发生的一起登革热暴发疫情进行调查,分析其感染来源,并对防控措施效果进行评价。 方法 采取描述性流行病学方法对东莞市2016年发生的一起登革热暴发疫情进行描述;用新发病例数和蚊媒密度变化来评价防控措施的效果。 结果 东莞市莞城街道在8月7日-9月3日之间发生3例登革热轻症病例,2男1女,为同一商铺工作人员。其中两名确诊患者血清标本Ⅳ型登革病毒核酸阳性并分离到2株登革病毒株, 2株病毒株E基因测序、进化分析同源性为99.3%,与印度2014年病毒株同源性为99.1%。经采取人工灭蚊、清除蚊虫孳生地、开展健康教育等措施,疫点核心区和监控区的蚊媒密度逐渐降低,疫情于9月3日平息。 结论 本起疫情为一起由输入性病例或病媒引起的本地感染的Ⅳ型登革热暴发疫情。采取杀灭成蚊和清除蚊虫孳生地为主的措施可有效控制蚊媒密度,进而控制疫情。     

南宁市37例登革病毒1型E基因系统进化分析

目的 对南宁市37例登革病毒1型（DENV1）流行株E基因进行序列测定,分析其分子生物学特征,探讨其可能来源。方法 选取2014年12份、2019年25份,共37份经确证为DENV1感染者阳性血浆样本,RT PCR扩增E基因片段,测序后进行同源性比较、系统进化分析。结果 测序后共获得37条长度为1437bp的E基因核苷酸序列,与各参考株E基因序列构建系统进化树后共形成Ⅰ、Ⅱ、Ⅲ,3个较大的进化簇,进化簇Ⅰ包括10条2019年DENV1 E基因序列,与参考序列Singapore 2017遗传距离最近,序列相似度99.4%~99.5%;进化簇Ⅱ包括8条2019年DENV1 E基因序列,与参考序列GuangZhou 2018遗传距离最近,序列相似度99.3%~99.5%;进化簇Ⅲ包括7条2019年DENV1 E基因序列和8条2014年DENV1 E基因序列,与参考序列Vietnam 2016遗传距离最近,序列相似度98.4%~98.8%。结论 2019年南宁市输入性DENV1流行株最有可能来源于广州和越南,推断南宁市2019年出现的DENV1本地流行由2014年以来本地进化毒株和新输入毒株共同引起。     

2019年广西7份本地感染登革病毒E基因特征分析

目的 了解2019年广西本地感染登革病毒(Dengue virus,DENV)E基因特性,探索可能的输入来源。方法 采用实时荧光定量PCR（real - time fluorescence quantitative PCR,RT - qPCR）方法对广西本地感染登革热病例急性期血清样本进行病毒核酸检测并分型,扩增登革病毒 E基因后测序,测序结果与不同地区和国家的参考株进行同源性比较和系统进化分析。结果 53份登革热病例血清标本经RT - qPCR分型,结果42份（79.2%,42/53）登革病毒核酸阳性,其中南宁9份、梧州10份、玉林17份、崇左6份,均为DENV - 1型,其余11份为登革病毒核酸阴性,42份DENV - 1型阳性核酸样本经过E基因扩增共得到7份,其中南宁市1份、梧州市1份、玉林市2份、崇左市3份,进化分析结果显示7份样本均为DENV - 1型Genotype Ⅰ基因型,其中DENV1/GXNN/007/2019、DENV1/GXWZ/009/2019、DENV1/GXYL/011/2019、DENV1/GXYL/012/2019与2019年广东株（序列号:MN921500）同源性99.94%～100.00%,DENV1/GXCZ/015/2019、DENV1/GXCZ/016/2019、DENV1/GXCZ/017/2019与 2015年印度尼西亚株（序列号:MG894852）同源性达99.60%,与1945年夏威夷参考株（序列号:AF425619）比较存在12处氨基酸位点变异。结论 2019年广西登革病毒是Genotype Ⅰ基因型,推测病毒从广东和东南亚国家输入导致的本地流行,应加强登革热跨省、跨境传播的防控。     

Molecular epidemiology of dengue in North Kalimantan,a province with the highest incidence rates in Indonesia in 2019

ObjectivesDengue is endemic to Indonesia, a country that has largely varied geographical and demographic conditions across different regions. In 2019, dengue epidemic occurred in North Kalimantan province and recorded as the highest incidence rate in Indonesia. This study aims to investigate the molecular epidemiology of dengue during outbreak in the province and compare the epidemiological characteristics between two cities/towns in North Kalimantan, namely Malinau, an inland town surrounded by a dense rainforest, and Tarakan, an island city.MethodsA cross sectional study was conducted between September 2018 and July 2019. Dengue-like illness patients were recruited in hospitals and tested for dengue NS1 and IgG/IgM. Serological prevalence was measured using IgG ELISA, dengue virus (DENV) serotyping was conducted using RT-PCR and Envelope gene sequencing was performed to infer the virus origins and phylogeny. Clinical, demographical, and diagnostics data were also recorded and analyzed.ResultsWe recruited 523 patients, 261 from Malinau and 262 from Tarakan. Among them, 349 patients were confirmed dengue. Cases in Malinau had a higher proportion of confirmed dengue (82.0%) compared to those in Tarakan (51.5%). Cases in Malinau were more likely to be dengue hemorrhagic fever with more severe hematological features compared to those in Tarakan. All four DENV serotypes were detected in both cities, the most prevalent serotype being DENV-2. The genetic characteristics of the viruses in the two towns was similar except for DENV-3. No sylvatic DENV was detected as well as alphaviruses and non-dengue flaviviruses during the outbreak.ConclusionsThe molecular epidemiology of dengue in North Kalimantan revealed the similar virological characteristics but different clinical and demographic aspects in Malinau and Tarakan. The distinct dengue dynamics between different regions of Indonesia is prominent and this knowledge will be important for understanding future patterns of DENV transmission in the region.     

Molecular characterization of the E gene of dengue virus type 1 isolated in Guangdong province, China, in 2006

We determined the genetic relationships and origin of the dengue virus (DENV) responsible for an outbreak of dengue fever (DF) in Guangdong province, China, in 2006. Five DENV type 1 (DENV-1) isolates were obtained from human serum samples collected from DF patients during the outbreak. The nucleotide sequences of the E (envelope) gene were compared with those of 48 previous DENV-1 isolates: 18 from Guangdong province, one from Fujian province, one from Zhejiang province, and 28 from other countries in the South Asian region. The results suggested that four DENV-1 isolates identified in Guangdong province in 2006 might be in general circulation there, although these DENV-1 viruses may have been originally introduced into the province from other countries. In contrast, one isolate from Guangzhou city in 2006, may have been introduced by a recently imported case from Cambodia.     

Molecular investigation of the dengue outbreak in Karnataka,South India,reveals co-circulation of all four dengue virus serotypes

The growing incidence of dengue outbreaks in the state of Karnataka prompted us to study the circulating dengue virus (DENV) and their proportion among the suspected cases of dengue patients during the disease outbreak at Mysuru district of Southern India. The presence of the DENV in a patient's serum sample was identified by RT-PCR using previously published primer pairs targeting CprM gene. DENV serotyping was carried out by semi-nested multiplex PCR using serotype-specific primers and nucleotide sequencing. Three hundred fifty-five samples of serum from suspected dengue cases were collected, and 203 samples (57.18%) were found positives. In 2016, DENV-4 (97.87%) was found to be the most dominant DENV serotype either alone or as co-infection, followed by DENV-2 (8.51%) and DENV-3 (4.25%). In 47 positive cases, co-infection with more than one serotype was detected in 4 cases (8.51%). The analysis of the dengue cases in 2017, DENV-4 was dominating serotype (33.97%), followed by the emergence of DENV-2 (32.05%), DENV-3 (25.64%), and DENV-1 (25.00%). Our study also reports the circulation of all four DENV serotypes in the Mysuru district of Southern India, with concurrent infections rate of 16.66% in 2017. The present study provides information regarding the genetic variation among the circulating DENV serotype in an Indian state of Karnataka. The need for the studying genetic diversity of DENV will be useful during the continuous monitoring for disease burden as well as the development of appropriate prophylactic measures to control the spread of dengue infection.     

The distinct distribution and phylogenetic characteristics of dengue virus serotypes/genotypes during the 2013 outbreak in Yunnan,China: Phylogenetic characteristics of 2013 dengue outbreak in Yunnan,China

Since 2000, sporadic imported cases of dengue fever were documented almost every year in Yunnan Province, China. Unexpectedly, a large-scale outbreak of dengue virus (DENV) infection occurred from August to December 2013, with 1538 documented cases. In the current study, 81 dengue-positive patient samples were collected from Xishuangbanna, the southernmost prefecture of the Yunnan province, and 23 from Dehong, the westernmost prefecture of the Yunnan province. The full-length envelope genes were amplified and sequenced. Phylogenetic analysis revealed that nine strains (39.1%) and 14 strains (60.9%) from the Dehong prefecture were classified as genotype I of DENV-1 and Asian I genotype of DENV-2, respectively. All strains from Xishuangbanna were identified as genotype II of DENV-3. Bayesian coalescent analysis indicates that the outbreak originated from bordering southeastern Asian countries. These three epidemic genotypes were predicted to originate in Thailand and then migrate into Yunnan through different routes.     

Characterization of the 2013 dengue epidemic in Myanmar with dengue virus 1 as the dominant serotype

In 2013 in Myanmar, dengue epidemic occurred with 20,255 cases including 84 deaths. This study aimed to determine the serological and molecular characteristics of dengue virus (DENV) infection among children with clinical diagnosis of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) during this period. Single acute serum samples were collected from 300 children in Mandalay Children Hospital, Mandalay, Myanmar. Out of the 300 children, 175 (58.3%) and 183 (61%) were positive for anti-dengue IgM and anti-dengue IgG, respectively. Among the IgM positives, 41 (23.4%) had primary DENV infection. Thirty-nine DENV strains (23 DENV-1, 10 DENV-2 and 6 DENV-4) were successfully isolated after inoculation of the patient serum samples onto C6/36 cells. DENV 1 was the dominant serotype in the 2013 epidemic. There was no correlation between the infecting serotypes and clinical severities. The DENV-1 strains belonged to three lineages of the genotype 1; the DENV-2 strains were of the Asian I genotype and were separated into two lineages; and DENV-4 strains belonged to the same lineage of genotype I. It is of interest to note the diversity of DENV-1 and -2 circulating in the same location during June–August 2013. These DENV isolates were genetically close (98%–100%) to the other previously reported isolates from Myanmar and its neighboring countries, namely China, Thailand, Sri Lanka, Cambodia and Vietnam. Primary DENV infection was still high among the severe dengue cases. Different serotypes of DENV were co-circulating in 2013, however, genotype shift was not observed. Additionally, amino acid mutations were detected in the study strains not seen in the previously reported strains from other countries and Myanmar. This paper provided information on the circulating serotypes for the last 15 years and the recent dengue situation in Mandalay, Myanmar after 2006.     

登革热伴出血与伴出疹患者实验室检查的特征分析

目的 分析比较2014年广东省登革热暴发流行期间登革热伴出血与登革热伴出疹患者的实验室检查特征.方法 将广州市第八人民医院收治的51例登革热伴出血与151例登革热伴出疹的住院患者纳入研究,采用实时荧光PCR方法检测登革病毒(DENV)核酸,ELISA测定DENV的IgM和IgG抗体,流式细胞术检测CD37CD47CD8+淋巴细胞亚群;比较两组研究病例的实验室资料,并进行统计学分析.结果 登革热伴出血患者的中性粒细胞、AST、血浆凝血酶原时间、活化部分凝血酶时间和尿蛋白阳性率分别为(56.77±19.11)×109/L、80.00(45.00,109.00) U/L、13.40(12.85,13.95)s、47.50(42.90,53.20)s和44.7％,均高于登革热伴出疹患者,差异有统计学意义(t=2.591,Z=2.495、3.184、2.435,x2=9.786,P均＜0.05或＜0.01);登革热伴出血患者的单核细胞、嗜酸性粒细胞、CD4+、CD8+、PLT、凝血酶原活动度和血浆纤维蛋白原分别为(9.79±4.96)×109/L、[0.10 (0.00,1.00)]×109/L、372 (220,585)个/μL、258 (155,466)个/μL、[53.00 (32.00,82.00)]×109/L、[93.55(86.57,102.66)]％和2.48(2.04,2.92) g/L,均低于登革热伴出疹患者,差异有统计学意义(t=-2.045,Z=-4.054、-1.962、-2.676、-3.806、-2.876和-2.111,P均＜0.05或＜0.01).登革病毒IgM抗体阳性166例(83.42％),IgG抗体阳性33例(16.58％).89例患者DENV核酸分型分析显示,DENV-1感染81例(91.01％),DENV-2感染3例(3.37％),DENV-1和DENV-2混合感染4例(4.49％),DENV-3感染1例(1.12％).另外,51例登革热伴出血患者中重症登革热9例(17.65％),151例登革热发热伴出疹的患者中重症登革热2例(1.32％),差异有统计学意义(x2=16.684,P＜0.01).结论 2014年广东省登革热暴发流行中,大部分登革热患者为初次的DENV-1感染;登革热伴出血患者在凝血功能、肝肾功能及免疫功能等方面明显较登革热伴出疹患者差;在临床上,应警惕发热伴出血患者发展为重症登革热.     

Emergence of dengue virus serotype 3 on Mayotte Island, Indian Ocean

A serosurvey carried out in 2006 in Mayotte, a French overseas collectivity in the Indian Ocean, confirmed previous circulation of dengue virus (DENV) on the island, but since the set up of a laboratory-based surveillance of dengue-like illness in 2007, no case of DENV has been confirmed. In response to an outbreak of DENV-3 on Comoros Islands in March 2010 surveillance of dengue-like illness in Mayotte was enhanced. By September 15, 76 confirmed and 31 probable cases of DENV have been identified in Mayotte. In urban and periurban settings on the island, Aedes albopictus is the predominant Aedes species, but Ae. aegyptii remains the most common species in rural areas. Given the epidemic potential of dengue virus in Mayotte, adequate monitoring including early detection of cases, timely investigation and sustained mosquito control actions remain essential.     

广州市荔湾区2006年登革热疫情流行病学特征分析

目的 分析广州市荔湾区2006年登革热疫情流行病学特征,探讨预防控制措施.方法 对各医院报告的病例进行流行病学个案调查;采集病例血样作血清学或病原学检测;对疫点进行蚊媒调查,在疫点周围开展病例搜索.共接报350例病例(包括疑似病例),采集336份血标本进行血清学检测,检出登革热IgM和(或)IgG阳性296份,其中12例分离到登革热病毒;共对176个疫点进行处理.结果 广州市荔湾区2006年共报告登革热病例310例,发病率为43.66/10万(按户籍人口计算),无死亡病例;疫情涉及20个行政街,有4个暴发点;流行季节为7月上旬至11月中旬,高峰在8月下旬和9月上旬;病毒为登革Ⅰ型;男性177例,女性133例,性别比1.33∶1;发病年龄最大为78岁,最小为3岁,以青壮年为主,20～39岁136例,占43.87%.结论 该区存在有利登革热流行的自然、社会因素,预防控制是一项长期、复杂的工作,今后要加强疫情预测预报,加快老城区和城中村的改造.