[Investigation on TT virus infection among various populations in Shenzhen]

A polymerase chain reaction assay with nested primers (nested PCR) deduced from the well conserved sequences of TTV ORF1 region was established to detect TTV DNA. PCR products from the 2 patients with non A-G hepatitis were cloned and sequenced to confirm its specificity. By using this assay, we tested the serum samples of 90 normal individuals, 88 paid blood donors, 79 intravenous drug users and 29 patients with non A-G hepatitis in Shenzhen, China. The positive rates of TTV DNA were 7.8%, 9.0%, 41.7% and 44.8%, respectively. TTV DNA was detected in 14 of the 90 normal individuals and 88 paid blood donors without any symptoms of liver disease. The results of this study suggest that TTV infection is common in normal population and the paid blood donors. The intravenous drug users are at high risk for TTV infection. TTV would be responsible for a part of non A-G hepatitis.