Study on the Molecular Prevalence and Genotypic Distribution of Torque Teno Virus in Iranian Hemodialysis Patients

This case-control study investigated the prevalence, genotypic distribution, and associated factors of Torque Teno Virus (TTV) infection in a cohort of 1576 hemodialysis (HD) patients compared to 1000 healthy individuals in Iran. This study is aimed at assessing the epidemiological profile of TTV, while also exploring its relationship with coinfections and various demographic factors, given the unclear clinical significance of TTV. Nested PCR and sequencing techniques were utilized to identify TTV DNA and its genotypes. The prevalence of TTV was significantly higher in patients undergoing HD, at 51.8%, compared to just 11.5% in healthy individuals. Coinfections were also notable, with 16.8% of HCV-positive, 5.3% of HBV-positive, and 3.0% of HIV-positive HD patients also carrying TTV. Genotypic analysis revealed distinct distributions: Genotypes 3, 17, 11, and 13 were more common in HD patients, while Genotypes 1, 3, and 17 were more prevalent in controls. Additionally, there was a significant correlation between advanced age and longer dialysis duration with TTV positivity. Variations in TTV prevalence across different studies emphasize the influence of methodological and geographical factors, underscoring the need for standardized diagnostic approaches. While the pathogenicity of TTV remains unclear, its potential as an indicator of immune compromise or coinfection risk warrants further investigation. This study highlights the need for enhanced monitoring in HD units to reduce transmission and stresses the importance of long-term research to clarify TTV's clinical significance. The findings emphasize the need for tailored infection control measures for high-risk groups, particularly in regions with a higher prevalence of HCV/HBV.