Prevalence and implication of TT virus infection: Minimal role in patientswith non-A-E hepatitis in Taiwan

TT virus (TTV) is a newly identified human DNA virus and little is known ab out its clinical significance. The aim of the study was to explore the prev alence of TTV infection in different risk populations and in patients with various liver diseases. Viral DNA was studied in 190 high-risk individuals, 97 household contacts, 52 patients with acute hepatitis A, 32 patients wit h non-A-E hepatitis including 13 fulminant hepatitis, 200 asymptomatic hepa titis B surface antigen (HBsAg) carriers, 100 patients with chronic hepatit is C, and 100 healthy adults. TTV infection was more frequent in high-risk groups (26-70%), patients with acute or fulminant non-A-E hepatitis (42-45% ), and hepatitis C carriers (36%) than in healthy adults (10%) and hepatiti s B carriers (15%). However, most of subjects with TTV infection alone had no or only mild hepatitis, and the same rate of m/ DNA in pre-hepatitis ser um samples and constant serum TTV titers during hepatitis episodes were obs erved in two patients with acute non-A-E hepatitis. Phylogenetic analysis o f the Taiwanese TTV isolates showed genetic heterogeneity and most (68%) is olates were TTV type 1. No particular strain was found to be associated wit h fulminant non-A-E hepatitis. (C) 1999 Wiley-Liss, Inc.