Interspousal transmission of TT virus: Low efficiency and lack of apparentrisk factors

Background: The TT virus (TTV) is a newly identified human DNA virus and li ttle 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 c ases and the related risk factors. Methods: Serum TTV-DNA was studied in spouses of 41 subjects with TT viremi a. For couples in which both husband and wife had TT viremia, nucleotide se quences of the open reading frame-1 region were analyzed by phylogenetic tr ee constructions. Results: Three (7%) of 41 spouses were positive for TTV-DNA. No differences were noted between index patients with seropositive spouses and those with out seropositive spouses with regard to clinical characteristics, including parenteral risk factors and exposure duration. Nucleotide sequence compari son and phylogenetic tree analysis of the viral genome in three TTV-infecte d couples revealed the isolates to be closely related in two, with a homolo gy of 97 and 98%, respectively. Conclusions: These results suggest that interspousal transmission of TTV do es occur; however, the efficiency of transmission is low compared with hepa titis C virus and GB virus-C. There are no apparent risk factors for transm ission between spouses and further studies are needed to clarify other mode s of non-parenteral transmission. (C) 2000 Blackwell Science Asia Pry Ltd.