Department of Virology, National Institute of Public Health, Oslo, Norway.
TT virus (TTV), the first human circovirus to be discovered, appears to be present in most people; less is known about the prevalence of the related TTV-like mini virus (TLMV). A sensitive nested PCR, specific for TLMV, detected the virus in 48% of 201 sera (Norwegian blood donors) previously found to have a 90% prevalence of TTV. More samples were either positive for both or negative for both viruses than what would have been expected from a random distribution (p = 0.08). Sequence analysis revealed considerable heterogeneity of Norwegian TLMV as compared to international sequences, suggesting that TLMV is efficiently dispersed in human populations.