title: Characterization of severe fever with thrombocytopenia syndrome in rural regions of Zhejiang, China.
abstract: Severe fever with thrombocytopenia syndrome virus (SFTSV) infections have recently been found in rural regions of Zhejiang. A severe fever with thrombocytopenia syndrome (SFTS) surveillance and sero-epidemiological investigation was conducted in the districts with outbreaks. During the study period of 2011-2014, a total of 51 SFTSV infection cases were identified and the case fatality rate was 12% (6/51). Ninety two percent of the patients (47/51) were over 50 years of age, and 63% (32/51) of laboratory confirmed cases occurred from May to July. Nine percent (11/120) of the serum samples from local healthy people without symptoms were found to be positive for antibodies to the SFTS virus. SFTSV strains were isolated by culture using Vero, and the whole genomic sequences of two SFTSV strains (01 and Zhao) were sequenced and submitted to the GenBank. Homology analysis showed that the similarity of the target nucleocapsid gene from the SFTSV strains from different geographic areas was 94.2-100%. From the constructed phylogenetic tree, it was found that all the SFTSV strains diverged into two main clusters. Only the SFTSV strains from the Zhejiang (Daishan) region of China and the Yamaguchi, Miyazakj regions of Japan, were clustered into lineage II, consistent with both of these regions being isolated areas with similar geographic features. Two out of eight predicted linear B cell epitopes from the nucleocapsid protein showed mutations between the SFTSV strains of different clusters, but did not contribute to the binding ability of the specific SFTSV antibodies. This study confirmed that SFTSV has been circulating naturally and can cause a seasonal prevalence in Daishan, China. The results also suggest that the molecular characteristics of SFTSV are associated with the geographic region and all SFTSV strains can be divided into two genotypes.
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, P.R. China; Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Center for Disease Control and Prevention of Daishan, Zhoushan, Zhejiang, P.R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.affiliation: Health Sciences Research Institute and School of Natural Sciences, University of California Merced, Merced, California, United States of America.
authors.forename: David M
authors.initials: DM
authors.lastname: Ojcius
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, P.R. China.
authors.forename: Xiuyu
authors.initials: X
authors.lastname: Lou
authors.affiliation: Center for Disease Control and Prevention of Daishan, Zhoushan, Zhejiang, P.R. China.
authors.forename: Chengwei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, P.R. China.
authors.forename: Cen
authors.initials: C
authors.lastname: feng
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, P.R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Center for Disease Control and Prevention of Daishan, Zhoushan, Zhejiang, P.R. China.
authors.forename: Zhongfa
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Zhoushan Hospital, Zhoushan, Zhejiang, P.R. China.
authors.forename: Shibo
authors.initials: S
authors.lastname: Li
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, P.R. China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D002044:Bunyaviridae Infections / Q000453:epidemiology / Q000821:virology; D002681:China / Q000453:epidemiology; D062665:Epidemiological Monitoring; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000276:immunology; D005334:Fever / Q000150:complications* / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000235:genetics; D016856:Phlebovirus / Q000235:genetics; D010802:Phylogeny; D012424:Rural Population / Q000706:statistics & numerical data*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D016036:Seroepidemiologic Studies; D013577:Syndrome; D013921:Thrombocytopenia / Q000150:complications* / Q000453:epidemiology* / Q000821:virology
chemical_list: D018985:Epitopes, B-Lymphocyte; D019590:Nucleocapsid Proteins