TT virus (TTV) is not associated with acute sporadic hepatitis.

A novel virus, TT virus (TTV), recently discovered by Okamoto et al. in the serum of a patient with posttransfusion hepatitis, is thought to be one of the causative agents of blood-borne acute hepatitis. The association of this virus with acute sporadic hepatitis was evaluated. TTV DNA was detected in 4 (4.9%) of 81 cases of acute hepatitis A, in 5 (16.7%) of 30 cases of acute hepatitis B, in 1 (25.0%) of 4 cases of acute hepatitis C, in 1 (9.1%) of 9 cases of cytomegalovirus and Eppstein-Barr infection, and in 8 (13.6%) of 59 cases of acute hepatitis of unknown etiology. These positive rates of TTV in various etiologies did not differ significantly amongst each other, and were similar to those of healthy volunteers, i.e. 12.0% (12/100). The comparison of levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, hepaplastin test and prothrombin time between TT virus-positive and -negative patients did not show any differences. This indicates that TTV is neither a main causative agent of acute sporadic hepatitis of unknown etiology, nor does it affect the clinical features of acute hepatitis with already known etiology.