Huang Xueyong, Liu Licheng, Du Yanhua, Wu Weili, Wang Haifeng, Su Jia, Tang Xiaoyan, Liu Qi, Yang Yinhui, Jiang Yongqiang, Chen Weijun, Xu Bianli
Center for disease control and prevention of Henan Province, Zhengzhou, China.
State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China.
PLoS Negl Trop Dis. 2014 Oct 16;8(10):e3237. doi: 10.1371/journal.pntd.0003237. eCollection 2014 Oct.
In 2007, a novel bunyavirus was found in Henan Province, China and named fever, thrombocytopenia and leukocytopenia syndrome virus (FTLSV); since then, FTLSV has been found in ticks and animals in many Chinese provinces. Human-to-human transmission has been documented, indicating that FTLSV should be considered a potential public health threat. Determining the historical spread of FTLSV could help curtail its spread and prevent future movement of this virus.
METHOD/PRINCIPAL FINDINGS: To examine the pattern of FTLSV evolution and the origin of outbreak strains, as well to examine the rate of evolution, the genome of 12 FTLSV strains were sequenced and a phylogenetic and Bayesian phylogeographic analysis of all available FTLSV sequences in China were performed. Analysis based on the FTLSV L segment suggests that the virus likely originated somewhere in Huaiyangshan circa 1790 (95% highest probability density interval: 1756-1817) and began spreading around 1806 (95% highest probability density interval: 1773-1834). Analysis also indicates that when FTLSV arrived in Jiangsu province from Huaiyangshan, Jiangsu Province became another source for the spread of the disease. Bayesian factor test analysis identified three major transmission routes: Huaiyangshan to Jiangsu, Jiangsu to Liaoning, and Jiangsu to Shandong. The speed of FTLSV movement has increased in recent decades, likely facilitated by modern human activity and ecosystem changes. In addition, evidence of RNA segment reassortment was found in FTLSV; purifying selection appears to have been the dominant force in the evolution of this virus.
Results presented in the manuscript suggest that the Huaiyangshan area is likely be the origin of FTLSV in China and identified probable viral migration routes. These results provide new insights into the origin and spread of FTLSV in China, and provide a foundation for future virological surveillance and control.
2007年，在中国河南省发现了一种新型布尼亚病毒，命名为发热伴血小板减少和白细胞减少综合征病毒（FTLSV）；从那时起，在中国多个省份的蜱虫和动物中都发现了FTLSV。已有文献记载该病毒存在人传人现象，这表明FTLSV应被视为一种潜在的公共卫生威胁。确定FTLSV的历史传播情况有助于遏制其传播，并预防该病毒未来的扩散。
方法/主要发现：为了研究FTLSV的进化模式和暴发毒株的起源，以及进化速率，对12株FTLSV毒株的基因组进行了测序，并对中国所有可用的FTLSV序列进行了系统发育和贝叶斯系统地理学分析。基于FTLSV L片段的分析表明，该病毒可能于1790年左右起源于淮阳山的某个地方（95%最高概率密度区间：1756 - 1817），并于1806年左右开始传播（95%最高概率密度区间：1773 - 1834）。分析还表明，当FTLSV从淮阳山传入江苏省时，江苏省成为了该疾病传播的另一个源头。贝叶斯因子检验分析确定了三条主要传播途径：淮阳山至江苏、江苏至辽宁、江苏至山东。近几十年来，FTLSV的传播速度有所加快，这可能是受现代人类活动和生态系统变化的推动。此外，在FTLSV中发现了RNA片段重配现象；纯化选择似乎是该病毒进化的主导力量。
本文的研究结果表明，淮阳山地区可能是中国FTLSV的起源地，并确定了可能的病毒迁移路线。这些结果为FTLSV在中国的起源和传播提供了新的见解，并为未来的病毒学监测和控制奠定了基础。
