献血人群感染TTV的检测及部分DNA序列分析

目的调查志愿无偿献血人群中输血传播病毒（TTV）的感染情况和分析TTV DNA部分基因序列。方法以TTV ORF1保守区设计两对引物，用巢式多聚酶链式反应（PCR）检测TTV DNA，并克隆和测序。结果在血液筛查合格的无偿献血人群中检出TTV DNA的阳性率为5．0％（5／100）。在单一转氩酶异常，HBV、HCV和HIV血清标记物正常的献血人群检出TTV DNA的阳性率为5．6％（4／71）。两者有非常显著性差异（P〈0．01）。与日本首例TTV-N22株相比，SZT1和SZT2株基因序列同源性为98．9％（3／272）和96．7％（9／272），SZT3和SZT4株为67．3％（89／272）和86．0％（38／272）。结论在符合献血条件的人群中存在无症状TTV携带者。与之相比较，在ALT异常献血人群中TTV流行率相对较高，对其部分基因序列的比较显示了较大的变异性。

The detection of TTV infection among blood donation population and the analysis of TTV DNA sequence

Objective To detect transfusion tr ansmitted virus(TTV)infection among voluntary non-remunerated blood donors and t o analyze TTV partial nucleotide sequence.Methods TTV DNA was detected by a ne sted polymerase chain reaction(PCR)assay with two pairs of primers designed agai nst TTV ORF1.The PCR products were cloned and DNA genes were sequenced. Result s The positive rates of TTV DNA were 5.0% (5/100) and 5.6% (4/71) respectivel y among eligible donors past through blood screening tests and ALT ineligible do nors whose HBV,HCV and HIV markers were negative.The nucleotide homology of SZ T1and SZT2 reached respectively 98.9% (3/272) and 96.7% (9/272) as against TTV-N22 of Japan,and the homology of SZT3 and SZT4 reached 67.3% (89/272) and 86.0% (38/272).Conclusion There were asymptomatic TTV carriers among bloo d population eligible for blood donation through blood screening tests.In compa rison with the asymptomatic donors,prevalent rate for blood donation population with abnormal ALT level was relative high and variation of the partial gene of TTV showed evidently.