Prevalence of the newly described human circovirus, TTV, in United States blood donors

BACKGROUND: A novel nonenveloped single-stranded circular DNA virus (TTV) w as recently identified. The prevalence of TTV in blood donors in the United States is, however, still unclear. STUDY DESIGN AND METHODS: Viral DNA was detected in US blood donors from fi ve cities by using two sets of TTV primers: NG059/NG061/NG063 primers, whic h amplified the conserved region of strains 1 and 2, and T801/T935 primers, which amplified the 5' end region of the TTV sequence. A TTV antibody assa y system was based on the detection of the truncated open reading frame (OR F)-1 (amino acids 1-411) from type 1b. The truncated ORF-1 was expressed as a fusion protein in Escherichia coil, and the fusion protein was used as t he antigen in the antibody assay system. RESULTS: Viremia was detected in 21 (8.4%) of 250 donors by use of NG059/NG 061/NG063 primers and 104 (41.6%) of 250 by use of T801/T935 primers. There was little correlation among the assays, which suggests the preferential d etection of different strains with the different primers. TTV antibody was detected in 38 of 100 donors: 32 (84%) of 38 with concurrent TTV viremia an d 6 (16%) of 38 without TTV viremia. TTV viremia and/or TTV antibody-positi ve samples were detected in 52 (52%) of 100 of US blood donors. CONCLUSION: Evidence of infection or exposure to TTV appears to be common a mong blood donors in United States.