TT virus (TTV) infection is extremely widespread in the general population. A sensitive real-time PCR assay was developed that quantitated accurately the most prevalent TTV genotypes in Italy. When used to test 217 individuals for TTV viraemia, the overall prevalence was 94%. Viraemia levels varied widely amongst individual subjects, with no major differences related to gender or age. The highest TTV titres were in haemophiliacs and in patients with non-A-E hepatitis, but they did not differ from the group with miscellaneous diseases. HIV- and HCV-infected subjects and patients with primary liver diseases had TTV loads similar to those of healthy individuals. (C) 2001 Wiley-Liss, Inc
