title: The prospective evaluation of viral loads in patients with severe fever with thrombocytopenia syndrome.
abstract: BACKGROUND
  Severe fever with thrombocytopenia syndrome (SFTS), caused by novel bunyavirus (SFTSV) is a potentially fatal disease that was first identified in China. Person to person transmission through contact with blood or body fluids was considered as an important infection route.
  
  
  OBJECTIVE
  The study is designed to investigate the longitudinal viral loads following SFTSV infection and to identify factors affecting viral shedding in SFTS patients.
  
  
  METHODS
  A prospective, observational study was performed on 208 laboratory-confirmed SFTSV infected patients in Xinyang, Henan Province. Sequential serum samples were collected on admission and during the hospitalization for quantification of SFTSV RNA by real-time RT-PCR.
  
  
  RESULTS
  The viral RNA was undetectable in 55.6% of the patients on admission into the hospital, becoming detectable in most cases until three days and attained maximum level on six days after disease onset. This was followed by an obvious decrease thereafter, but maintained detectable for over 20 days. Viral load was independently predictable of severe disease outcome throughout the hospitalization. Viral load of >10(7)copies/mL was predictable of fatal outcome. The serum levels of PLT, WBC, LDH, AST and CK were significantly associated with viral loads level.
  
  
  CONCLUSIONS
  The diagnosis of SFTSV infection based on PCR test should be performed at least three days after disease onset. Peaking viral loads were attained around six days after disease, posing a highest risk of human-to-human transmission.
authors.affiliation: The 154 Hospital, Peoples Liberation Army, Xinyang 464000, PR China.
authors.forename: Zhen-Dong
authors.initials: ZD
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
authors.forename: Jian-Gong
authors.initials: JG
authors.lastname: Hu
authors.affiliation: School of Public Health, Peking University, Beijing 100191, PR China. Electronic address: qingbinlu@bjmu.edu.cn.
authors.forename: Qing-Bin
authors.initials: QB
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China; Graduate School of Anhui Medical University, Hefei 230032, PR China.
authors.forename: Chen-Tao
authors.initials: CT
authors.lastname: Guo
authors.affiliation: The 154 Hospital, Peoples Liberation Army, Xinyang 464000, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Cui
authors.affiliation: The Shangcheng County People's Hospital, Shangcheng, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China; Graduate School of Anhui Medical University, Hefei 230032, PR China.
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Wang
authors.affiliation: The 154 Hospital, Peoples Liberation Army, Xinyang 464000, PR China.
authors.forename: Shu-Li
authors.initials: SL
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China; Graduate School of Anhui Medical University, Hefei 230032, PR China.
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
authors.forename: Pan-He
authors.initials: PH
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
authors.forename: Xiao-Ai
authors.initials: XA
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China. Electronic address: lwbime@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
authors.forename: Wu-Chun
authors.initials: WC
authors.lastname: Cao
mesh_terms: D000328:Adult; D000368:Aged; D002044:Bunyaviridae Infections / Q000821:virology*; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016856:Phlebovirus / Q000302:isolation & purification*; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044967:Serum / Q000821:virology; D013997:Time Factors; D019562:Viral Load; D017201:Virus Shedding
chemical_list: D012367:RNA, Viral
keywords: Prospective study; RT-PCR; SFTSV; Severe fever with thrombocytopenia syndrome; Viral loads