2014年云南省瑞丽市登革1和2型病毒流行的分子流行病学研究

Molecular epidemiology of dengue virus types 1 and 2 in Ruili,Yunnan,2014

目的阐明云南省中缅边境的瑞丽市2014年登革热流行的登革病毒血清型及分子流行病学特点。方法收集登革热病例资料,采集患者急性期血清标本,用RT-PCR法检测登革病毒核酸,并进行登革病毒C/Pre M区核苷酸序列测定和分析。结果 2014年6-12月,瑞丽市共确诊登革热病例292例,其中本地感染病例139例(47.77%),输入性病例153例(52.23%;缅甸输入152例,广州输入1例)。2014年瑞丽市登革热本地感染病例发病率为72.77/10万。主要流行地区为瑞丽市城区、姐告开发区和勐卯镇。经登革病毒核酸检测和序列测定,从患者血清中获得65株病毒的C/Pre M区基因核苷酸序列,其中本地感染40例,缅甸输入25例。进化分析表明,登革1型病毒53株(本地感染31例,缅甸输入22例),2型11株(本地9例,缅甸输入2例),4型1株(缅甸输入病例),它们均与东南亚登革病毒流行株具有较近的亲缘关系。结论 2014年瑞丽市发生了输入性和本地感染并存的登革热流行,缅甸木姐市和中国瑞丽市均存在登革1和2型病毒的共同流行,来自缅甸木姐市的登革热输入性病例是引起瑞丽市登革热本地流行的主要原因。

Objective To understand the serotype of dengue virus and molecular epidemiologic characteristics of an outbreak of dengue fever in Ruili,a city in Sino-Myanmar border area,in Yunnan province in 2014. Methods The incidence data of dengue fever in Ruili were collected. Serum samples from the dengue fever cases in acute phase were collect to detect the viral nucleic acid by using RT-PCR assay. The phylogenetic tree was constructed according to the nucleotide sequence of C / Pre Mgene fragments of dengue viruses. Results A total of 292 cases of dengue fever were laboratory confirmed in Ruili from June to December,2014,in which 139 were indigenous cases（ 47. 77%）,153 were imported cases（ 52. 23%）,i. e.,152 from Myanmar and 1 from Guangzhou of China. The local incidence of dengue fever was 77. 69 / lakh. The disease mainly occurred in urban area,Jiegao development zone and Mengmao town of Ruili. The results of viral nucleic acid detection and sequencing indicated that the nucleotide sequences of C / Pre Mregion of 65 virus strains were obtained,including40 local strains and 25 imported strains from Myanmar. The phylogenetic tree indicated that 53 strains belonged to serotype 1（ 31 local strains and 22 imported strains from Myanmar）,11 strains belonged to serotype 2（ 9 local strains and 2 imported strains from Myanmar） and 1 strain belonged to serotype 4（ from Myanmar）. All the 65 strains shared high homology with the strains from Southeast Asia countries. Conclusion In the outbreak of dengue fever in Ruili in 2014,both indigenous cases and imported cases were detected. Dengue virus serotype 1 and 2 circulated in both Mujie of Myanmar and Ruili of China in 2014. The transmission of dengue fever from Mujie of Myanmar to Ruili of China was the main cause of local dengue fever epidemic.