输血传播病毒母婴传播的研究

目的：探讨深圳市孕产妇输血传播病毒（TTV）感染情况及其在母婴间的传播途径。方法：应用套式－聚合酶链反应（Nest－PCR）对400例正常孕产妇分娩前的血清及其新生儿的脐血血清标本、产妇的乳汁配对进行了TTV DNA检测，对阳性的母亲及其新生儿进行的6个月随访，并对其中13对TTV DNA阳性的母血、母乳及其婴儿的血，共做32株克隆，通过DNA序列测定比较分析母婴TTV感染株之间核苷酸的序列同源性。结果：在400对配对标本中，62例孕妇血清、4例新生儿脐血清、20例母乳检测出TTV DNA，孕母TTV感染率15．5％（62／400），出生时母婴TTV传播率6．5％（4／62），阳性母亲乳TTV DNA检出率32．2％（20／62），配对比较母婴间TTV感染株序列同源性为97．4％－99．8％，经6个月随访母血TTV DNA阳性的婴儿血TTV DNA由阴转阳率为38．1％（16／42）。 结论：TTV可通过围产期和哺乳期母婴传播的途径感染，对胎儿的危害及新生儿生长发育的影响值得重视。

Study on mother-to-child transmission route of transfusion transmitted virus infection

Objective To investigate the prevalence of TT virus infection in pregnant women in Shenzhen and the role of mother-to -child transmission route in the TTV infection. Methods TTV DNA were detected by nested PCR in sera, cord blood and breast milk samples from 400 mother-infant pairs. TTV DNA positive mothers were followed up for 6 months for monitoring TTV DNA. Thirty two TTV DNA PCR products amplified from blood and milk samples of 13 mother-infant fairs were cloned and sequenced. Results By means of PCR, TTV DNA were detected in 62 of mothers' serum samples, 4 of 400 cord blood samples, and 20 of 400 milk samples, respectively. Therefore, 6.5%(4/62) of infants are likely to be infected with TTV from their mothers during the fetal period. Direct sequencing of TTV DNA from 13 mother-child pairs showed identical isolates (nucleotide homology from 97.5% to 99%), Follow-up sera of 42children, whose mothers were TTV DNA positive, showed 16 cases turned out to be existence of TTV viremia at 6 months old. Conclusions Our data proved the mother-to-child transmission route of TTV infection.TTV can be transmitted transplacentally and postnatally by the way of breast feeding as well. The increase of TTV prevalence during the 6 months after birth, suggests the postnatal transmission route of TTV may be of more importance, and further study is needed to address whether preventive measure should be done.