Huang Jing, Lin Xin-Zhu, Lai Ji-Dong, Fan Yan-Feng
Department of Neonatology, Women and Children's Hospital, School of Medicine, Xiamen University/Xiamen Maternal and Child Care Hospital, Xiamen, Fujian 361001, China.
Zhongguo Dang Dai Er Ke Za Zhi. 2019 Jun;21(6):567-572. doi: 10.7499/j.issn.1008-8830.2019.06.013.
To study the incidences of group B streptococcus (GBS) colonization in pregnant women and GBS infection in their preterm infants, and to investigate the risk factors for GBS colonization in preterm infants.
A total of 859 women who delivered before term from January 2017 to January 2018 were enrolled in this prospective cohort study. Bacterial culture was performed for GBS using the swabs collected from the rectum and the lower 1/3 of the vagina of the pregnant women on admission. A total of 515 of the above cases underwent real-time PCR assay for testing of GBS DNA. Bacterial culture was performed for GBS using the oropharyngeal secretion, gastric fluid or blood samples in preterm infants born to the 859 pregnant women. Peripheral blood samples from the pregnant women and umbilical cord blood samples from their preterm infants were collected to determine the level of anti-GBS capsular polysaccharide antibody. The incidence of GBS infection and perinatal risk factors for GBS colonization in the preterm infants were examined.
The positive rate for GBS in the rectal and vaginal cultures was 14.8% (127/859) among the 859 pregnant women, and the positive rate in the GBS DNA testing was 15.1% (78/515). There were 976 live-birth preterm infants delivered by 859 pregnant women, and 4.4% (43/976) of whom were GBS positive. Four preterm infants had early-onset GBS diseases, including pneumonia in two cases and sepsis in two cases. In 127 preterm infants delivered by 127 GBS-positive pregnant women, the preterm infant group with a gestational age between 34 and 37 weeks had a significantly lower GBS positive rate and a significantly higher level of anti-GBS capsular polysaccharide antibody compared with the preterm infant group with a gestational age of less than 34 weeks (P=0.013 and 0.001 respectively). A multivariate logistic regression analysis revealed that premature rupture of membranes time >18 hours and chorioamnionitis were independent risk factors for GBS colonization in preterm infants (OR=6.556 and 6.160 respectively; P<0.05).
GBS positive rate and anti-GBS capsular polysaccharide antibody level in preterm infants are correlated with gestational age. premature rupture of membranes time >18 hours and chorioamnionitis may increase the risk of GBS colonization in preterm infants.
研究孕妇B族链球菌（GBS）定植率及其早产婴儿的GBS感染情况，并探讨早产婴儿GBS定植的危险因素。
选取2017年1月至2018年1月间早产的859名妇女纳入这项前瞻性队列研究。入院时采集孕妇直肠及阴道下1/3处拭子进行GBS细菌培养。上述病例中的515例进行实时PCR检测GBS DNA。对859名孕妇所生早产婴儿的口咽分泌物、胃液或血液样本进行GBS细菌培养。采集孕妇外周血样本及其早产婴儿的脐血样本，测定抗GBS荚膜多糖抗体水平。检查早产婴儿GBS感染发生率及GBS定植的围产期危险因素。
859名孕妇中，直肠及阴道培养GBS阳性率为14.8%（127/859），GBS DNA检测阳性率为15.1%（78/515）。859名孕妇共分娩976名活产早产婴儿，其中4.4%（43/976）GBS阳性。4名早产婴儿发生早发性GBS疾病，其中2例为肺炎，2例为败血症。在127名GBS阳性孕妇所分娩的127名早产婴儿中，孕龄34至37周的早产婴儿组GBS阳性率显著低于孕龄小于34周的早产婴儿组，抗GBS荚膜多糖抗体水平显著高于孕龄小于34周的早产婴儿组（P值分别为0.013和0.001）。多因素logistic回归分析显示，胎膜早破时间>18小时和绒毛膜羊膜炎是早产婴儿GBS定植的独立危险因素（OR值分别为6.556和6.160；P<0.05）。
早产婴儿GBS阳性率及抗GBS荚膜多糖抗体水平与孕龄相关。胎膜早破时间>18小时和绒毛膜羊膜炎可能增加早产婴儿GBS定植风险。
