Prevalence and genotypic distribution of GB virus C and torque teno virus among patients undergoing hemodialysis

Patients undergoing hemodialysis are at increased risk of infection with blood-borne viruses, including GB virus C (GBV-C) and torque teno virus (TTV). However, the prevalence and genotypic distribution of these viruses in the assessed patients undergoing hemodialysis remains unclear. The present study investigated these issues and the possibility of nosocomial transmission among patients undergoing hemodialysis in a unit in Yogyakarta, Indonesia. GBV-C RNA was detected in 92/161 patients (57.1%) by nested reverse-transcription polymerase chain reaction. Phylogenetic analysis of the 5'-untranslated region (UTR) classifed the GBV-C isolates into genotypes 6 (85%), 2 (8%), 4 (6%), and 3 (1%). TTV DNA was detected in all patients by the amplifcation of the 5'-UTR and open reading frame-1 (ORF1) by nested and semi-nested polymerase chain reaction. Phylogenetic analysis based on the ORF1 revealed that genotype 1 was dominant (84%), followed by genotypes 2 (10%) and 3 (6%). The greater prevalence of GBV-C genotype 6 in patients undergoing hemodialysis compared with the general population and the identical sequences observed in multiple isolates provided strong evidence of patient-to-patient transmission. The prevalence of TTV in hemodialysis patients was similar to that observed in the general population, and only one pair of TTV isolates was identical. These results indicated that nosocomial infection was not the main cause of the high prevalence of TTV in patients undergoing hemodialysis. In conclusion, GBV-C and TTV infections are common in patients undergoing hemodialysis in Yogyakarta, Indonesia, and transmission is likely to be nosocomial in the case of GBV-C infection.