Prevalence of TT virus DNA in eastern Taiwan aborigines

We studied the prevalence of TT virus (TTV) DNA in the general population of the eastern Taiwan aborigine villages, about 11% (34 of 317). There is no association between the presence of HBsAg and TTV DNA or between the presence of HCV RNA and TTV DNA. Therefore, the infection of HBV or HCV and the presence of TTV DNA appear to be independent from each other. The association between the presence of TTV DNA and the elevated alanine aminotransferase (and/or aspartate aminotransferase) activity was also investigated. The presence of TTV DNA was not found to be correlated with abnormal liver function (P = 0.574) when age, gender, and the presence of HBsAg, HCV RNA, and HGV RNA were all considered in the assay. The sequence homology of TTV DNA fragments between different isolates from Taiwan and N22 (the clone obtained from the original prototype strain) from Japan ranged from 84 to 97%. The recombinant protein encoded by the TTV DNA fragment corresponding to the open reading frame of N22 was expressed in E. coli successfully. However, no serum response against the recombinant protein was detected.