title: Interspousal transmission of TT virus: low efficiency and lack of apparent risk factors.
abstract: BACKGROUND
  The TT virus (TTV) is a newly identified human DNA virus and little is known about its non-parenteral transmission. The aim of the present study was to explore the prevalence of TTV infection in spouses of index cases and the related risk factors.
  
  
  METHODS
  Serum TTV-DNA was studied in spouses of 41 subjects with TT viremia. For couples in which both husband and wife had TT viremia, nucleotide sequences of the open reading frame-1 region were analyzed by phylogenetic tree constructions.
  
  
  RESULTS
  Three (7%) of 41 spouses were positive for TTV-DNA. No differences were noted between index patients with seropositive spouses and those without seropositive spouses with regard to clinical characteristics, including parenteral risk factors and exposure duration. Nucleotide sequence comparison and phylogenetic tree analysis of the viral genome in three TTV-infected couples revealed the isolates to be closely related in two, with a homology of 97 and 98%, respectively.
  
  
  CONCLUSIONS
  These results suggest that interspousal transmission of TTV does occur; however,the efficiency of transmission is low compared with hepatitis C virus and GB virus-C. There are no apparent risk factors for transmission between spouses and further studies are needed to clarify other modes of non-parenteral transmission.
authors: Department of Internal Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei.
authors: C J
authors: CJ
authors: Liu
authors: J H
authors: JH
authors: Kao
authors: W
authors: W
authors: Chen
authors: R J
authors: RJ
authors: Tsai
authors: P J
authors: PJ
authors: Chen
authors: M Y
authors: MY
authors: Lai
authors: D S
authors: DS
authors: Chen
mesh_terms: D000328:Adult; D004266:DNA Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission*; D004279:DNA, Viral / Q000032:analysis* / Q000097:blood; D018562:Disease Transmission, Infectious; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D018454:Spouses; D022783:Torque teno virus / Q000235:genetics; D014766:Viremia / Q000097:blood
chemical_list: D004279:DNA, Viral