Prevalence and Genotyping of Torque Teno Virus in HBV/HIV and Chronic HBV Patients in Iran

Background: Torque teno virus (TTV) was the first human Anelloviridae detected in a Japanese patient with an unknown type of hepatitis in 1997. TTV is by far the first known single-stranded circular DNA virus infecting human. In spite of its widespread nature in human population, its pathogenesis is still unclear. In addition, information regarding TTV infection in Iranian population is limited. Therefore, we attempted to determine the prevalence and genotype of TTV in three groups: HIV/HBV patients, chronic hepatitis B patients, and healthy individuals. Methods: The presence of TTV DNA in sera was investigated using PCR. The primer sets encompassing two 5΄-UTR and N22 regions were used, and the positive products were collected for sequencing. Phylogenetic tree was generated based on N22 region and using the MEGA 7 software. Results: TTV DNA was detected in 452 patients with HIV/HBV and chronic hepatitis B, as well as in healthy control groups. The results from PCR indicated positive rates for these three groups, 48%, 54%, and 49.3% using 5΄-UTR primer and 15.1%, 12%, and 8% using N22 primer, respectively. Conclusion: Five genogroups were observed, which the second group was found to be the most frequent. The results of 5΄-UTR primer showed more prevalence of TTV DNA comparing to N22 primer in patients and healthy control.