[TT virus--characteristics, occurrence and routes of transmission].
Recent discovery of a novel DNA virus from the serum of a Japanese patient (T.T.) has prompted further studies directed on possible role of TT virus in the development of cryptogenic hepatitis. The TT is an unenveloped and circular DNA virus. TTV possesses single stranded DNA genome and comprises 3537 to 3853 nucleotides. TTV is similar to the Circoviridae and possesses three open reading frames. Phylogenetic analysis revealed up to 30% nucleotide sequence divergence in the 16 virus genotypes. TTV infection can be detected by polymerase chain reactions, in situ hybridization and by specific antibodies to TTV. TTV DNA has been identified in the serum of patients with cryptogenic hepatitis, hepatitis B and C, hepatocellular carcinoma as well as in healthy individuals. TTV has been found also in the peripheral blood leukocytes, bone marrow cells, liver biopsies as well as in feces and breast milk. Some animals including cattle, sheep, pigs and chicken appeared to have TTV viremia. Recent detection of TTV in nonblood products, such as saliva and feces suggest in addition to parenteral also nonparenteral routes of TTV transmissions including sexual and fecal-oral.
Liweń
Izabela
I
Zakład Genetyki Człowieka PAN, Poznaniu.
Januszkiewicz-Lewandowska
Danuta
D
Nowak
Jerzy
J
D000818:Animals; D004266:DNA Virus Infections / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission; D006521:Hepatitis, Chronic / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction; D022783:Torque teno virus / Q000235:genetics / Q000302:isolation & purification