新肝炎病毒TTV在各类高危人群中分子流行病学研究

为观察新肝炎病毒TTV在各类高危人群中的感染状况和基因分型，在日本株TTV ORF,保守区合成了特异性引物，采用巢式聚合酶链反应(nPCR)两次扩增血清TTV DNA，对各类人群中TTV DNA分别进行了分子克隆和部分基因测序，并与日本报道的TTV DNA基因序列比较。结果显示：从非甲．戊型和非庚型肝炎病人、血清HBsAg阳性的肝炎病人、正常献血员、静脉内吸毒者和女性性乱者中，分别获得的6份TTV DNA克隆，其基因序列与日本株TTV ORF,部分基因核苷酸序列同源性为97％～99％，均属于TTV la型。提示：我国各类高危人群感染TTV 以la型为主；TTV基因型与疾病发生和传播方式关系不大。

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.