Gerner P, Oettinger R, Gerner W, Falbrede J, Wirth S
Children's Hospital Wuppertal, University of Witten/Herdecke, Germany.
Pediatr Infect Dis J. 2000 Nov;19(11):1074-7. doi: 10.1097/00006454-200011000-00009.
It is currently unknown which mechanisms are responsible for TT virus (TTV) infection in early childhood and whether it may be transmitted in utero from mother to infant.
The prevalence, mode and extent of maternal TTV transmission was investigated by testing blood, cord blood and breast milk samples from mother-infant pairs for the existence of the novel DNA virus.
By means of polymerase chain reaction, TTV DNA was detected in 57 (41.3%) of 138 mothers and in 19 (13.8%) of 138 cord blood samples; therefore 33.3% of infants are likely to be infected by their mothers during the fetal period. Direct sequencing of TTV DNA from 2 mother-child pairs showed identical isolates. Follow-up sera from 3 TTV infected babies showed persistence of viremia. In blood samples from newborns older than 1 week 9 (27.3%) of 33 sera were TTV-positive. Viral sequences were also detected in 2 of 2 breast milk samples. In none of the infected subjects were biochemical or clinical signs of hepatitis observed.
Our data prove that TT virus is efficiently transmitted transplacentally. The increase of its prevalence in the group of newborns older than 1 week suggests that it may be furthermore transmitted postnatally. Therefore in our Caucasian population, vertical transmission, particularly in utero transmission, of TTV is likely to account for a major part of TTV infection in early childhood. However, no disease activity could be established for the novel virus by this infection route.
目前尚不清楚哪些机制导致幼儿感染TT病毒（TTV），以及该病毒是否可经子宫由母亲传播给婴儿。
通过检测母婴配对的血液、脐带血和母乳样本中是否存在这种新型DNA病毒，来研究母亲TTV传播的发生率、方式和程度。
通过聚合酶链反应，在138名母亲中的57名（41.3%）以及138份脐带血样本中的19份（13.8%）检测到TTV DNA；因此，33.3%的婴儿在胎儿期可能被母亲感染。对2对母婴的TTV DNA进行直接测序，结果显示分离株相同。对3名TTV感染婴儿的随访血清显示病毒血症持续存在。在出生1周以上新生儿的血液样本中，33份血清中的9份（27.3%）TTV呈阳性。在2份母乳样本中的2份也检测到病毒序列。在所有感染受试者中均未观察到肝炎的生化或临床体征。
我们的数据证明TT病毒可通过胎盘有效传播。其在出生1周以上新生儿组中的患病率增加表明，它可能在出生后进一步传播。因此，在我们的白种人群中，TTV的垂直传播，尤其是子宫内传播，可能是幼儿期TTV感染的主要原因。然而，通过这种感染途径未发现该新型病毒有疾病活动。
