2015年杭州市首例本地感染登革热病例病原溯源调查

Molecular tracing of pathogen of the first local dengue fever case in Hangzhou

目的对杭州市首例本地感染登革热病例开展调查及病原分子学溯源。方法对首例本地感染登革热病例开展流行病学调查,采集患者血清进行登革病毒核酸和抗体检测。提取病毒核酸后扩增E基因并测序,利用生物信息学软件进行多序列比对排列及构建进化树。结果该病例的登革病毒核酸及Ig M抗体均为阳性,基因序列比对及进化分析,病毒株为登革病毒1型GⅣ亚型,与韩国2007年1例从菲律宾旅游输入病例分离的病毒株亲缘关系最近,核苷酸和氨基酸同源性为98.9%和99.6%,与菲律宾2010年的2株病毒核苷酸和氨基酸同源性为98.6%和99.6%,病毒株来源于菲律宾的可能性较大。结论杭州市首例本地感染登革热病例可能是由菲律宾旅游归国的输入性病例引发的二代病例。

Objective To understand the pathogen＇ s molecular characteristics of the first local dengue fever case in Hangzhou. Methods The epidemiological stLrvey was conducted and the serum sample was collected from the dengue fever patient to detect dengue virus nucleic acids and antibody. The envelope （E） gene of the viruswas amplified and sequenced. The genotype of the isolate was analyzed with bioinformatics software. Results The serum sample of the patient was positive for dengue virus nucleic acids and anti-dengue IgM. The homologous and phylogenetic analysis showed that the isolate belonged to dengue virus type 1 and the sub genotype was G IV. It had a closest phylogenetic relationship with the strain isolated from the case imported from the Philippines in Korea in 2007, sharing 98. 9% and 99. 6% homology in nucleotide sequence and amino acid sequence respectively; and the strain isolated shared 98.6% and 99. 6% homology in sequences of nucleotide and amino acid respectively with the strain isolated from the Philippines in 2010, indicating that it might originated from the Philippines. Conclusion The first local dengue fever case in Hangzhou might be caused by the imported case who returned from Philippines after the travel in this country.