Detection of hepatitis B virus (HBV) genotypes and co-infection with Torque Teno Virus (TTV) in HBV-positive patients at a tertiary care center in Puducherry, India.

Hepatitis B Virus (HBV) infection is a global health concern. HBV genotypes differ in disease potential and geographical distribution. These genotypes impact the diagnostic and preventive strategies. Furthermore, limited data are available on Torque Teno Virus (TTV) co-infections with HBV. Hence, this study evaluated HBV infection prevalence, genotype distribution, and the presence of TTV among HBV-positive patients. During the study period, a total of 1820 serum samples were collected and tested for HBsAg using ELISA method. Of this, 43 (2.36%) were HBsAg positive. These HBsAg-positive samples were further subjected to conventional PCR followed by Sanger sequencing for HBV and TTV genotype detection. In this study, only HBV genotypes D (subgenotype D2) (97%) and A (subgenotype A1) (3%) were detected. 15% of HBV-infected patients were positive for TTV in which genotype 1A was detected in 66.67% of cases and 1B in 33.33% of cases. To the best of our knowledge, this study represents the first of its kind from Puducherry to document Torque Teno Virus (TTV) co-infection in HBV-positive cases from the non-renal transplant population. This study underscores the significance of HBV genotypes and TTV co-infection in HBV patients. Further studies and surveillance are needed to monitor circulating HBV genotypes and explore TTV's role in co-infection, particularly its pathogenesis and clinical implications.