High frequency of postnatal transmission of TT virus in infancy

DNA of TT virus (TTV), a novel human circovirus, was tested for in 116 moth er-infant pairs who had participated in the adult T-cell leukemia preventio n program (APP) in Nagasaki, Japan, and refrained from breast-feeding. By p olymerase chain reaction with Okamoto's seminested primers, 36 of the 115 ( 31%) mothers were positive. At the age of 6-8 months, 7 of 29 (24%) and 6 o f 72 (8%) infants born to infected and uninfected mothers were positive, re spectively (P = 0.047; RR, 2.90). Maternal TTV DNA load did not correlate w ith infantile infections. Since 99 of 100 (99%) cord blood samples were neg ative and all the mothers refrained from breast-feeding, the infantile TTV transmission would not be intrauterine or milk-borne. Between 6-8 and 12-21 months of age, 4 of 12 (33%) and 5 of 22 (23%) children born to infected a nd uninfected mothers turned positive, respectively (NS). At 12-21 months o f age, 8 of 21 (38%) and 12 of 32 (38%) children born to infected and uninf ected mothers were positive, respectively (NS). These results indicate that the TTV infection prevails in children at a frequency comparative to that in their mothers within the first 2 years of life, regardless of the matern al TTV status.