Experimental and Natural Infections of Goats with Severe Fever with Thrombocytopenia Syndrome Virus: Evidence for Ticks as Viral Vector.
Experimental and Natural Infections of Goats with Severe Fever with Thrombocytopenia Syndrome Virus: Evidence for Ticks as Viral Vector.
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血小板减少综合症病毒严重发烧山羊的实验和自然感染：蜱作为病毒载体的证据
DOI：
10.1371/journal.pntd.0004092
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发表时间：
2015
影响因子：
3.8
通讯作者：
Zhou M
中科院分区：
文献类型：
--
作者：
Jiao Y;Qi X;Liu D;Zeng X;Han Y;Guo X;Shi Z;Wang H;Zhou M
研究背景重症发热伴血小板减少综合征病毒（severe fever with thrombocytopenia syndrome virus，SFTSV）是我国中东部地区首次发现的一种可引起严重威胁生命的传染病。虽然在自由生活和寄生蜱中检测到病毒RNA，但SFTSV的载体仍然不稳定。方法/主要发现首先，在生物安全等级2（BSL-2）设施中进行山羊实验感染研究，以调查动物之间的病毒传播。结果表明，感染动物不通过呼吸道或消化道途径向外散毒，对照动物未感染。然后，在SFTSV流行区进行了自然感染研究。在研究中心使用一组未处理山羊作为哨兵动物。收集各种日常样品，包括山羊血清、蜱和蚊子，用于病毒RNA和抗体（仅来自血清）检测以及病毒分离。我们从自由生活和寄生蜱而不是蚊子中检测到病毒RNA，并从蜱感染后的山羊中检测到病毒RNA。我们还观察到血清转换的所有成员的动物队列随后。从一只感染山羊及其寄生蜱中分离到的两株病毒的S片段序列在核酸水平上具有100%的同源性。结论/意义在我们的自然感染研究中，山羊之间的密切接触似乎不会传播SFTSV，然而，未感染的动物在蜱侵染后被感染，并且来自感染山羊及其寄生蜱的两个病毒分离物具有100%的序列同一性。说明山羊群自然感染的病原来自环境因素。其中，蜱，特别是优势种长角血蜱，可能是这种病原体的载体。这项研究的发现可能有助于当地卫生当局制定和集中预防措施，以控制这种感染。
Background Severe fever with thrombocytopenia syndrome virus (SFTSV), the causative agent for the fatal life-threatening infectious disease, severe fever with thrombocytopenia syndrome (SFTS), was first identified in the central and eastern regions of China. Although the viral RNA was detected in free-living and parasitic ticks, the vector for SFTSV remains unsettled. Methodology/Principal Findings Firstly, an experimental infection study in goats was conducted in a bio-safety level-2 (BSL-2) facility to investigate virus transmission between animals. The results showed that infected animals did not shed virus to the outside through respiratory or digestive tract route, and the control animals did not get infected. Then, a natural infection study was carried out in the SFTSV endemic region. A cohort of naïve goats was used as sentinel animals in the study site. A variety of daily samples including goat sera, ticks and mosquitoes were collected for viral RNA and antibody (from serum only) detection, and virus isolation. We detected viral RNA from free-living and parasitic ticks rather than mosquitoes, and from goats after ticks’ infestation. We also observed sero-conversion in all members of the animal cohort subsequently. The S segment sequences of the two recovered viral isolates from one infected goat and its parasitic ticks showed a 100% homology at the nucleic acid level. Conclusions/Significance In our natural infection study, close contact between goats does not appear to transmit SFTSV, however, the naïve animals were infected after ticks’ infestation and two viral isolates derived from an infected goat and its parasitic ticks shared 100% of sequence identity. These data demonstrate that the etiologic agent for goat cohort’s natural infection comes from environmental factors. Of these, ticks, especially the predominant species Haemaphysalis longicornis, probably act as vector for this pathogen. The findings in this study may help local health authorities formulate and focus preventive measures to contain this infection.