Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China.
Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China.
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中国流行区蜱传白蛉病毒引起发热伴血小板减少综合征的生态学
DOI：
10.1371/journal.pntd.0004574
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发表时间：
2016-04
影响因子：
3.8
通讯作者：
Xing Z
中科院分区：
文献类型：
--
作者：
Li Z;Bao C;Hu J;Liu W;Wang X;Zhang L;Ji Z;Feng Z;Li L;Shen A;Liu X;Zhao H;Tan W;Zhou J;Qi X;Zhu Y;Tang F;Cardona CJ;Xing Z
背景发热伴血小板减少综合征（SFTS）是由SFTS病毒（SFTSV）引起的，SFTSV是布尼亚病毒科的一种蜱传白蛉病毒。研究发现，人类、家畜和野生动物都可能感染SFTSV。然而，病毒的生态、循环和传播在很大程度上仍然未知。2011 - 2014年，通过病毒分离或免疫荧光法报告确诊人间SFTS病例67例。2013-2014年，我们在江苏疫区的植被和小型野生兽类中采集蜱虫9984只，采用实时RT-PCR技术在长角血蜱和黄血蜱的采集和饲养过程中检测SFTSV-RNA。病毒RNA在长角锥虫幼虫第一次吸血前被鉴定出来，这在自然界中从未被证实过。利用RT-PCR和ELISA分别检测了野生哺乳动物（欧洲羊尾猴和阿兰索猴）的SFTSV-RNA和抗体。从非采食季节捕获的欧洲鹰尾虱中分离出一株SFTSV活株，抗体效价较高。此外，利用ELISA法在候鸟天鹅应答鸟和中国链蚤中检测到SFTSV抗体。结论/意义在未充血的幼虫中检测到SFTSV- rna，提示长角夜蛾在自然界中可能存在SFTSV的垂直传播，推测长角夜蛾是SFTSV的宿主。小型野生哺乳动物如欧洲羊尾猴和阿兰索猴均可感染SFTSV，并可作为天然扩增宿主。我们的数据表明，野生鸟类可能感染SFTSV或携带感染SFTSV的蜱，从而可能通过迁徙飞行途径促进SFTSV的远距离传播。这些发现为了解SFTSV的生态学、宿主和自然界的传播提供了新的见解，并将有助于制定新的措施来防止其在区域和全球范围内的快速传播。
Background Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a tick-borne phlebovirus in family Bunyaviridae. Studies have found that humans, domestic and wildlife animals can be infected by SFTSV. However, the viral ecology, circulation, and transmission remain largely unknown. Methodology/Principal Findings Sixty seven human SFTS cases were reported and confirmed by virus isolation or immunofluorescence assay between 2011 and 2014. In 2013–2014 we collected 9,984 ticks from either vegetation or small wild mammals in the endemic area in Jiangsu, China, and detected SFTSV-RNA by real-time RT-PCR in both questing and feeding Haemaphysalis longicornis and H. flava. Viral RNA was identified in larvae of H. longicornis prior to a first blood meal, which has never been confirmed previously in nature. SFTSV-RNA and antibodies were also detected by RT-PCR and ELISA, respectively, in wild mammals including Erinaceus europaeus and Sorex araneus. A live SFTSV was isolated from Erinaceus europaeus captured during the off tick-feeding season and with a high SFTSV antibody titer. Furthermore, SFTSV antibodies were detected in the migratory birds Anser cygnoides and Streptopelia chinensis using ELISA. Conclusions/Significance The detection of SFTSV-RNA in non-engorged larvae indicated that vertical transmission of SFTSV in H. longicornis might occur in nature, which suggests that H. longicornis is a putative reservoir host of SFTSV. Small wild mammals such as Erinaceus europaeus and Sorex araneus could be infected by SFTSV and may serve as natural amplifying hosts. Our data unveiled that wild birds could be infected with SFTSV or carry SFTSV-infected ticks and thus might contribute to the long-distance spread of SFTSV via migratory flyways. These findings provide novel insights for understanding SFTSV ecology, reservoir hosts, and transmission in nature and will help develop new measures in preventing its rapid spread both regionally and globally.