Helmig Rikke B, Gertsen Jan B
Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark.
Department of Clinical Microbiology, Aarhus University Hospital, Skejby, Denmark.
Acta Obstet Gynecol Scand. 2017 Sep;96(9):1070-1074. doi: 10.1111/aogs.13169. Epub 2017 Jun 22.
Many pregnant women are treated with antibiotics during labor to prevent transmission of group B streptococcus (GBS, Streptococcus agalactiae) to their baby during passage of the birth canal, and so reduce the risk of serious infection of the newborn. Methods for intrapartum testing for GBS have been introduced to select women to whom intrapartum antibiotic prophylaxis should be offered. For such an intrapartum test to be useful in clinical practice, it has to be specific as well as sensitive. The aim of the present study is to evaluate the accuracy of the polymerase chain reaction (PCR) assay compared with an optimized culture method for GBS.
In the period from 12 May 2015 to 18 December 2015 we collected rectovaginal swabs from 106 women in the labor ward presenting in labor between gestational week 35 and 36 or presenting with prelabor/preterm prelabor rupture of membranes (PROM/PPROM) for > 14 h after gestational week 34 . We performed GBS culture (reference standard) and a molecular GBS test (Xpert GBS, Cepheid Ltd., Sunnyvale, CA, USA).
Based on intrapartum culture, 23.6% (25/106) were colonized with GBS. Intrapartum PCR showed a colonization rate of 25.7% (27/105). The sensitivity of the test was 100% (86.28-100%). The specificity of the test was 97.5% (91.26-99.70%). The positive predictive value was 92.6%. In one case, we had no result with PCR testing, giving an invalid test rate of < 1%.
The PCR test has sufficient accuracy to direct intrapartum antibiotic prophylaxis for GBS transmission during delivery.
许多孕妇在分娩期间接受抗生素治疗，以防止分娩过程中B族链球菌（GBS，无乳链球菌）传播给婴儿，从而降低新生儿严重感染的风险。已引入分娩期GBS检测方法，以筛选应接受分娩期抗生素预防的女性。为使这种分娩期检测在临床实践中有用，它必须既特异又敏感。本研究的目的是评估聚合酶链反应（PCR）检测与优化的GBS培养方法相比的准确性。
在2015年5月12日至2015年12月18日期间，我们从106名在分娩病房的女性中收集了直肠阴道拭子，这些女性在妊娠35至36周时分娩，或在妊娠34周后胎膜早破/早产前胎膜早破（PROM/PPROM）超过14小时。我们进行了GBS培养（参考标准）和分子GBS检测（Xpert GBS，美国加利福尼亚州桑尼维尔市的塞菲德有限公司）。
根据分娩期培养，23.6%（25/106）的女性被GBS定植。分娩期PCR显示定植率为25.7%（27/105）。该检测的敏感性为100%（86.28 - 100%）。该检测的特异性为97.5%（91.26 - 99.70%）。阳性预测值为92.6%。在一例中，PCR检测无结果，无效检测率<1%。
PCR检测具有足够的准确性，可指导分娩期抗生素预防以防止分娩期间GBS传播。
