[A molecular epidemiologic study of TT virus in various population].

To investigate infection and sequence divergence of TT virus in various population, a nested polymerase chain reaction (nPCR) assay with primers from TTV ORF1 genome was used to detect serum TTV DNA. TTV DNAs from various population were cloned and sequenced. Six gene sequences derived from two patients with non-A through non-E and non-G hepatitis, a hepatitis patient with HBsAg, a normal blood donor, an intravenous drug user and a woman prostitute, were compared with known sequence of TTV isolate (N22) reported by Okamoto, Japan. The nucleotide homology were 96%-98% and the whole sequences belonged to la genotype. The data indicate that TTV DNA from various population in China might chiefly be la genotype. There is no correlation between genotype and disease transmission and development.