Abstract
BackgroundIn 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 FindingsTo 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.ConclusionResults 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.
Highlights
In 2007, the fever, thrombocytopenia and leukopenia syndrome (FTLS; called severe fever with thrombocytopenia syndrome, SFTS) was first reported in Henan province, China [1,2]
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
Little variation was observed in the overall nucleotide lengths of the S, M, and L segments from viruses circulating in Henan from 2011 to 2012, and pairwise differences in the percent nucleotide identities were low, ranging from 0.1%–4.2%, 0.2%– 4.7% and 0.1%–5.8% for the L, M, and S segments, respectively
Summary
In 2007, the fever, thrombocytopenia and leukopenia syndrome (FTLS; called severe fever with thrombocytopenia syndrome, SFTS) was first reported in Henan province, China [1,2]. Since this life-threatening disease has been reported in many Chinese provinces, including Hubei, Anhui, Jiangsu, Liaoning and Shandong. Laboratory tests show thrombocytopenia, leukopenia, increased urine protein, and elevated serum aspartate aminotransferase and alanine aminotransferase This disease was diagnosed as suspended human granulocytic anaplasmosis (HGA) infection [3]. In 2007, a novel bunyavirus was found in Henan Province, China and named fever, thrombocytopenia and leukocytopenia syndrome virus (FTLSV); since FTLSV has been found in ticks and animals in many Chinese provinces. Determining the historical spread of FTLSV could help curtail its spread and prevent future movement of this virus
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
