TT virus infection in Italy: prevalence and genotypes in healthy subjects,viral liver diseases and asymptomatic infections by parenterally transmitted viruses

This study was aimed to evaluate TT virus prevalence in subjects with hepat itis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency viru s (HIV) infections in patients affected by hepatitis of unknown origin (non -A-non-E hepatitis) and in healthy subjects who had not been exposed to HBV , HCV and HIV. A total of 317 subjects were tested; 40 were HBsAg asymptoma tic carriers, 57 subjects were anti-HCV positive (45 without chronic hepati tis and 12 with HCV-related chronic hepatitis), and 27 had chronic non-A-no n-E hepatitis. Fifty-seven subjects were intravenous drug users (IVDUs) (52 with HCV or/and EHV infections), seven patients underwent a liver transpla nt for fulminant hepatitis and 137 were healthy subjects from the general p opulation. Overall, TTV-DNA was detected in 62 subjects (19.6%): in 17.9% o f the HBsAg carriers, in 14% of the anti-HCV-positive patients (in 8.3% and in 15.5% of patients with and without chronic hepatitis, respectively), in 22.2% of non-A-non-E hepatitis patients, in 22.8% of IVDUs, in 57.1% of fu lminant hepatitis patients. TTV-DNA was also found in 20.4% healthy subject s. The prevalence in the different subgroups was not statistically differen t. The genotypes were identified in 40 of the 62 (64.5%) TTV-DNA positive s amples: genotype la in 17.5%, lb in 27.5%, genotype 2 in 27.5%, genotype 3 in 15.0%, genotype 4 in 5.0% and genotype 5 in 7.5%; the genotype distribut ion in the subsets of patients was not significantly different. In conclusi on, this study showed that TTV infection is common in Italy; it is widespre ad throughout the entire population and five genotypes are present in Sardi nia. Our results further dismiss the role of TTV as cofactor in influencing the clinical course of infections with other hepatitis viruses as well as the role of HIV in enhancing TTV transmission and replication.