[Isolation and identification of Arbovirus in Hainan province, 2017-2018].

Objective: To understand the types and distribution of Arboviruses in Hainan province. Methods: Blood-sucking insects were collected in Hainan province from 2017 to 2018. After laboratory treatment, BHK-21 cells and C6/36 cells were inoculated with grinding supernatant of all blood-sucking insects to isolate all of involving virus. Arbovirus genes in blood-sucking insects were detected in parallel by RT-PCR method. Results: A total of 15 062 mosquitoes were classified into four genera (Culex, Armigeres, Aedes, Anopheles) and 11 360 midges were collected. Culex tritaeniorhynchus was in the majority and accounted for 92.88% (13 990/15 062) of all the mosquitoes collected. Four strains of virus isolates were notified by tissue culture method. Three strains of viruses belonged to Japanese encephalitis virus (JEV), with the other one as Getah virus (GETV). Five pools of JEV gene amplification were positive, from Culex tritaeniorhynchus. Results from the phylogenetic analysis showed that they belonged to genotype JEV-Ⅰ. The minimum infection rate of JEV was 0.57‰ (8/13 990). A total of 5 pools of Akabane virus (AKV) gene amplification were positive. The minimum infection rate of AKV was 0.44‰ (5/11 360). Based on the S gene and M gene sequences of the virus, data from the phylogenetic analysis showed that the five AKV strains carried by midges in Hainan province were in a separate evolutionary branch and with formed unique geographical distribution. Conclusions: JEV and GETV had been isolated again from the mosquito specimens in this survey, since the 1980s. AKV was detected from the midge specimens in Hainan province. These results showed the needs of strengthening the programs on detection and monitor of JEV, GETV and AKV that were related to animal and human diseases in order to reduce the risks of related diseases in this area.目的： 了解海南省虫媒病毒种类及分布变化。 方法： 于2017－2018年在海南省野外采集吸血昆虫标本，所有吸血昆虫标本实验室处理后用BHK-21细胞和C6/36细胞进行病毒分离，同时使用RT-PCR平行检测吸血昆虫标本中虫媒病毒基因。 结果： 共采集到4属（库蚊、阿蚊、伊蚊、按蚊）15 062只蚊虫和11 360只蠓虫。采集的蚊虫中三带喙库蚊居多，占蚊虫采集总数92.88%（13 990/15 062）。经组织培养细胞共获得4株病毒分离物，其中3株乙型脑炎（乙脑）病毒、1株盖塔病毒，在5批三带喙库蚊标本中检测到乙脑病毒基因阳性。遗传进化分析结果显示这3株乙脑病毒和5批PCR筛检阳性的标本均属于基因1型乙脑病毒。当地乙脑病毒的最低感染率为0.57‰（8/13 990）。在5批蠓虫标本中检测阿卡斑病毒基因阳性，当地阿卡斑病毒的最低感染率为0.44‰（5/11 360）。基于病毒S基因和M基因序列的系统进化分析显示这5株阿卡斑病毒处于单独进化分支形成独特的地理分布特征。 结论： 继1980年代以来，从海南省的蚊虫标本中再次分离到乙脑病毒和盖塔病毒、蠓虫标本中检测到阿卡斑病毒。应加强乙脑病毒、盖塔病毒和阿卡斑病毒对人畜动物感染状况及疾病负担的监测，以减少对当地公共卫生健康的危害。.