Introduction: TT virus (TTV) is an unenveloped single-stranded circular DNA virus. Sensitive PCR (Polymerase Chain Reaction) methods with primers designed for very conserved regions of the viral genome (UTR) indicate high prevalence (> 90%) of TTV infection in general population of many countries world-wide. Although there has been no evidence of its relation to any liver or other specific disease to date, it is speculated that certain genotype(s) may be capable of causing hepatitis. A relationship between viral load and immune status of host is also suggested. This study was done to determine the prevalence of TTV infection in general population of Isfahan, Iran.

Methods : Serum samples were collected from 132 voluntary blood donors in Blood Transfusion Organization, Isfahan. Among them, four were positive for HBs-Ag and six for Anti-HCV antibody. DNA was extracted and subjected to PCR using consensus primers. The amplified PCR products were sequenced.

Results: TTV DNA was detected in 105 out of 132 examined samples (95% confidence interval: 73% to 86% with) These included ninety-five out of 122 healthy and 10 out of 10 hepatitis-positive sera.

Conclusion: The results showed high prevalence of TTV in general population of Isfahan which is the same as other areas studied. Determining the genotypes present in Isfahan population is suggested .

Hakim Research Journal 2007 9(4): 52- 58.