| prevalence and genetic diversity of tt virus genotype 21 (yonban virus) in brazil. | isolates of the newly characterized, single-stranded dna virus ttv, have been tentatively classified into four major phylogenetic groups and at least 28 genotypes. four japanese isolates, designated as yonban viruses, belong to the fourth group and to genotype 21. in this study, a genotype 21-specific pcr assay was standardized. with this assay, 48/184 (26%) serum samples and 76/167 (46%) saliva samples, collected from unselected ambulatory patients (aged 2 to 82) of a brazilian public hospital, ... | 2003 | 12607102 |