中国淮阳山地区由新蜱传布尼亚病毒引起的出血热

Hemorrhagic fever caused by a novel tick-borne Bunyavirus in Huaiyangshan,China

研究背景 2009-2010年4月至7月,我国淮阳山地区农民中出现不明原因的严重出血热样病例.方法 采集疑似病例的临床标本（血液、尿液、粪便和咽拭子）,在患者所在地采集蚊和蜱.从2例患者的血液样本中分离到2株病毒,并进行全基因组测序分析.采用病毒特异的RT-PCR对其他病例及节肢动物进行病毒检测,对RT-PCR阳性病例的临床和流行病学资料进行分析.结果 从2例患者的血液及从犬身上采集到的长角血蜱中分离到1种未知病毒.全基因组测序分析发现该病毒为布尼亚病毒科的一个新成员,与白蛉病毒属最接近,是其中的一个新分支.58例疑似病例中33例RT-PCR结果阳性.病例临床特征主要表现为发热、乏力、恶心、呕吐和腹泻.主要实验室结果包括白细胞及血小板减少,凝血时间异常和肝酶升高.3例患者出现出血症状,5例死亡（死亡率15%）.结论 我国淮阳山地区存在着一种严重威胁生命健康的新蜱传布尼亚病毒.对于该病毒的流行病学、地理分布,以及脊椎动物宿主的生态学等需要作进一步的研究.

Background：From April to July in 2009 and 2010,unexplained severe hemorrhagic fever-like illnesses occurred in farmers from the Huaiyangshan mountains range.Methods：Clinical specimens （blood,urine,feces,and throat swabs） from suspected patients were obtained and stored.Mosquitoes and ticks in affected regions were collected.Virus was isolated from 2 patients and characterized by whole genome sequencing.Virus detection in additional patients and arthropods was done by virus-specific reverse transcription （RT） PCR.Clinical and epidemiological data of RT-PCR confirmed patients were analyzed.Results：An unknown virus was isolated from blood of two patients and from Haemaphysalis ticks collected from dogs.Whole genome sequence analysis identified the virus as a novel member of the family Bunyaviridae,most closely related to the viruses of the genus Phlebovirus within which it forms a separate lineage.Subsequently,infection was confirmed by RT-PCR in 33 of 58 suspected patients.The illness in these patients was characterized by fever,severe malaise,nausea,vomiting,and diarrhea.Prominent laboratory findings included low white cell- and platelet counts,coagulation disturbances,and elevation of liver enzymes.Hemorrhagic complications were observed in 3 cases,5 （15%） patients died.Conclusions：A novel tick-borne Bunyavirus causing life-threatening hemorrhagic fever in humans has emerged in the Huaiyangshan mountain areas of China.Further studies are needed to determine the epidemiology,geographic distribution and vertebrate animal ecology of this virus.