一种新的可经输血传播病毒(TTV)的分子流行病学研究

MOLECULAR EPIDEMIOLOGICAL STUDY ON TTV INFECTION AMONG VARIOUS POPULATIONS IN SHENZHEN

目的分析深圳地区不同人群中 TTV(transfusion transmitted virus,TTV)感染情况及其基因型。方法在 TTV ORF1 设计引物,建立巢式聚合酶链反应,检测深圳地区不同人群血清中 TTV DNA。对 PCR 产物进行分子克隆,以荧光法(Applied Biosystems,373A)测序。结果 90例一般人群、88例有偿献血员、79例静脉毒瘾者、52例非甲～非庚型肝炎、67例乙型肝炎及72例丙型肝炎患者中,TTV DNA 阳性率分别为7.8%、9.0%、41.8%、48.0%、22.3%与27.8%。5株深圳 TTV(SZ1～SZ5)ORF1部分基因核苷酸序列同源性为66.2%～96.7%。基因分型5株中2株属Gl型(Gla亚型),3株属 G2型,其中2株为 G2b 型。结论深圳地区一般人群与职业献血员中 TTV 健康携带者较常见:静脉毒瘾者与非甲～非庚型肝炎患者是 TTV 感染的高危人群;乙型及丙型肝炎常重叠 TTV 感染;不同 TTV 分离株 ORF1部分基因序列变异可达33%,基因分型以 G1a 与 G2b 为主。

Objective To investigate transfusion transmitted virus(TTV)infection in various populations and sequence divergence among different TTV isolates.Methods A nested polymerase chain reaction(PCR)assay with primers from ORFI of TTV genome was establishied to detect TTV DNA in the serum samples from various populations in Shenzhen.PCR product was cloned and sequenced with the Applied Biosystems(373A).Results TTV DNA was detected in the sera from 7 of 90(7.8%)general individuals,8 of 88(9.0%)paid blood donors,33 of 79(41.8%)intravenous drug users,25 of 52(48.0%)patients with non A-non G hepatitis,15 of 67(22.3%)patients with hepatitis B and 20 of 72(27.8%)cases with hepatitis C.When partial sequence of ORF1 was compared among TTV isolates from 4 patients with non A-non G hepatitis and 1 blood donor,it showed divergence with differences 3.3% to 33%.Of the 5 sequences,2 belonged to genetic group G1(subgroup Gla)and the remaining 3 to genetic group G2.Conclusion The results of the study suggest that TTV infection is common in the general population and blood donors;TTV was detected frequently in patients with non A-non G hepatitis;the intravenous drug user is the population at high risk for TTV infection and the sequence difference of a partial gene among different TTV isolates may be up to 33%.