Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus (SFTSV). SFTSV is associated with a high mortality rate and has been reported in China, South Korea and Japan. SFTSV undergoes rapid changes owing to evolution, gene mutations, and reassortment between different strains of SFTSV. In this review, we summarize the recent cases and general properties of SFTS, focusing on the epidemiology, genetic diversity, clinical features, and diagnostics of SFTSV in China. From 2010 to October 2016, SFTS cases were reported in 23 provinces of China, with increased numbers yearly. Infection and death cases are mainly found in central China, where the Haemaphysalis longicornis ticks are spread. The national average mortality rate of SFTS infection was 5.3%, with higher risk to elder people. The main epidemic period was from May to July, with a peak in May. Thus, SFTS reminds a significant public health problem, and development of prophylactic vaccines and effective antiviral drugs will be highly needed.
Severe fever with thrombocytopenia syndrome virus(SFTSV) is a globe-shaped virus covered by a dense icosahedral array of glycoproteins Gn/Gc that mediate the attachment of the virus to host cells and the fusion of viral and cellular membranes. Several membrane factors are involved in virus entry, including C-type lectins and nonmuscle myosin heavy chain ⅡA. The post-fusion crystal structure of the Gc protein suggests that it is a class Ⅱ membrane fusion protein, similar to the E/E1 protein of flaviviruses and alphaviruses. The virus particles are internalized into host cell endosomes through the clathrin-dependent pathway, where the low pH activates the fusion of the virus with the cell membrane. With information from studies on other bunyaviruses, herein we will review our knowledge of the entry process of SFTSV. 相似文献
Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever disease caused by SFTSV, a newly discovered phlebovirus that is named after the disease. Currently, no effective vaccines or drugs are available for use against SFTSV infection, as our understanding of the viral pathogenesis is limited. Bortezomib(PS-341), a dipeptideboronic acid analog, is the first clinically approved proteasome inhibitor for use in humans. In this study, the antiviral efficacy of PS-341 against SFTSV infection was tested in human embryonic kidney HEK293 T(293 T) cells. We employed four different assays to analyze the antiviral ability of PS-341 and determined that PS-341 inhibited the proliferation of SFTSV in 293 T cells under various treatment conditions. Although PS-341 did not affect the virus absorption, PS-341 treatment within a non-toxic concentration range resulted in a significant reduction of progeny viral titers in infected cells.Dual-luciferase reporter assays and Western blot analysis revealed that PS-341 could reverse the SFTSV-encoded nonstructural protein(NS) mediated degradation of retinoic acid-inducible gene-1(RIG-I), thereby antagonizing the inhibitory effect of NSs on interferons and blocking virus replication. In addition, we observed that inhibition of apoptosis promotes virus replication. These results indicate that targeting of cellular interferon pathways and apoptosis during acute infection might serve as the bases of future therapeutics for the treatment of SFTSV infections. 相似文献
Severe fever with thrombocytopenia virus (SFTSV), an emerging tick-borne bandavirus, poses a significant public health threat in rural China. Since 2021, an increase of local cases has been noted in the rural-urban fringe of Beijing. This study aimed to assess the formation of natural foci in urban areas by conducting a field survey of ticks and hedgehogs from the second to fifth ring roads of Beijing. Our survey revealed a diverse tick population in city parks, including the major SFTSV vector, Haemaphysalis longicornis. Parthenogenetic H. longicornis, known for its role in the rapid spread of SFTSV, was identified in key locations such as Beihai Park and Taoranting Park, near the Forbidden City. Notably, high SFTSV seroprevalence and RNA prevalence were found in hedgehogs and parasitic ticks in the center of Beijing. Phylogenetic analyses of SFTSV RNA and mitochondrial sequences of parthenogenetic H. longicornis ticks revealed the existence of diverse lineages of SFTSV and H. longicornis ticks within Beijing, suggesting multiple invasion events happened. These findings reveal the circulation of SFTSV in central Beijing, highlighting the need for urgent attention and enhanced surveillance measures. 相似文献
Severe fever with thrombocytopenia syndrome phlebovirus(SFTSV) has a wide host range. Not only has it been found in humans, but also in many wild and domesticated animals. The infection of breeding deer on farms is a particularly worrisome public health concern due to the large amount of human contact and the diverse use of deer products, including raw blood. To investigate the prevalence of breeding domesticated deer, we examined the SFTSV infection rate on deer farms in South Korea from 2015 to 2017. Of the 215 collected blood samples, 0.9%(2/215) were found to be positive for viral RNA by PCR, and sequence analysis showed the highest homology with the KADGH human isolate. Both SFTSVspecific recombinant N and Gn protein-based ELISAs revealed that 14.0%(30/215) and 7.9%(17/215) of collected blood specimens were positive for SFTSV antibody. These results demonstrate that the breeding farm deer are exposed to SFTSV and could be a potential infection source for humans through direct contact or consumption of byproducts. 相似文献
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever in East Asia with case fatality up to 50%. SFTS is caused by SFTSV, a tick borne bunyavirus. In endemic area in China 1%–3% population was infected with SFTSV, but age is critical risk factor for hospitalization and death of SFTS patients. 相似文献
Severe fever with thrombocytopenia syndrome virus(SFTSV), the causative agent of a febrile human disease, was first identified from central and eastern provinces in China, and later in Japan and South Korea. Hubei Province is one of the major SFTS epidemic areas in the central part of China. This study reported the isolation of 11 new SFTSV strains from patients in Hubei Province collected in 2017. Extensive phylogenetic analyses were conducted based on the complete coding sequences of SFTSV segments including the new strains. It was suggested that five different SFTSV genotypes were circulating in Hubei, and 15 reassortment patterns and migration pathways correlated with each genotype were identified, which was more than previously recognized. Hubei Province was more involved in the evolutionary events of SFTSV than that previously thought in which the evolutionary events of SFTSV were reported to be independent from those in other epidemic regions. Further divergence of SFTSV strains was suggested by pairwise comparison of SFTSV sequences from each genotype and sequence identity normalized to representative strain in genotype C1. Subsequently,amino acid variations specific for genotype(s), strain(s), or cluster(s) were inspected, which may be related to differential biological activity of SFTSV strains/genotypes. In conclusion, we analyzed the current status of SFTSV phylogeny in Hubei Province and discussed the possible events correlated to SFTSV evolution. It provided an in-depth insight into SFTSV evolution, raising concerns for the use of proper SFTSV strains in future studies. 相似文献
Severe fever with thrombocytopenia syndrome virus(SFTSV) is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome(SFTS) in humans. The molecular mechanisms and host cellular factors required for SFTSV infection remain uncharacterized. Using a genome-wide CRISPR-based screening strategy, we identified a host cellular protein, sorting nexin 11(SNX11) which is involved in the intracellular endosomal trafficking pathway, as an essential cell factor for SFTSV infection. An SNX11-KO HeLa cell line was established, and SFTSV replication was significantly reduced. The glycoproteins of SFTSV were detected and remained in later endosomal compartments but were not detectable in the endoplasmic reticulum(ER) or Golgi apparatus. pH values in the endosomal compartments of the SNX11-KO cells increased compared with the pH of normal HeLa cells, and lysosomal-associated membrane protein 1(LAMP1) expression was significantly elevated in the SNX11-KO cells. Overall,these results indicated that penetration of SFTSV from the endolysosomes into the cytoplasm of host cells was blocked in the cells lacking SNX11. Our study for the first time provides insight into the important role of the SNX11 as an essential host factor in the intracellular trafficking and penetrating process of SFTSV infection via potential regulation of viral protein sorting, membrane fusion, and other endocytic machinery. 相似文献
Severe fever with thrombocytopenia syndrome (SFTS) caused by the SFTS virus (SFTSV) is an emerging disease in East Asia with a fatality rate of up to 30%. However, the viral-host interaction of SFTSV remains largely unknown. The heat-shock protein 90 (Hsp90) family consists of highly conserved chaperones that fold and remodel proteins and has a broad impact on the infection of many viruses. Here, we showed that Hsp90 is an important host factor involved in SFTSV infection. Hsp90 inhibitors significantly reduced SFTSV replication, viral protein expression, and the formation of inclusion bodies consisting of nonstructural proteins (NSs). Among viral proteins, NSs appeared to be the most reduced when Hsp90 inhibitors were used, and further analysis showed that their translation was affected. Co-immunoprecipitation of NSs with four isomers of Hsp90 showed that Hsp90 β specifically interacted with them. Knockdown of Hsp90 β expression also inhibited replication of SFTSV. These results suggest that Hsp90 β plays a critical role during SFTSV infection and could be a potential target for the development of drugs against SFTS. 相似文献
Virologica Sinica - Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne bunyavirus that causes hemorrhagic fever-like disease (SFTS) in humans with a case fatality... 相似文献
Hubei Province is a major epidemic area of severe fever with thrombocytopenia syndrome bunyavirus(SFTSV) in China. However, to date, a few SFTSV strains have been isolated from Hubei Province, preventing effective studies of epidemic outbreaks. Here, we report three confirmed patients(2015–2016) with typical symptoms of severe fever with thrombocytopenia syndrome disease(SFTS) who were farmers resident in different regions in Hubei Province. Three new SFTSV strains were isolated from the serum samples of each patient. Characterization of viral growth properties showed that there were no significant differences in virus production. All strains were completely sequenced, and phylogenetic analysis showed that unlike the other strains from Hubei province, which belonged to the SFTSV C3 genotype, one of the three strains belonged to the SFTSV C2 genotype. These results suggested that multiple SFTSV genotypes have been circulating in Hubei Province, providing insights into SFTSV evolution and improving our understanding of SFTSV prevalence in Hubei Province. 相似文献
Virologica Sinica - Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality (12%–30%). The mechanism by which the SFTS bunyavirus (SFTSV)... 相似文献
