Ramesh Babu Sandhya, McDermott Rachel, Farooq Irum, Le Blanc David, Ferguson Wendy, McCallion Naomi, Drew Richard, Eogan Maeve
a Department of Obstetrics and Gynaecology , Rotunda Hospital , Dublin , Ireland.
b Department of Laboratory Medicine , Rotunda Hospital , Dublin , Ireland.
J Obstet Gynaecol. 2018 Jan;38(1):49-54. doi: 10.1080/01443615.2017.1328490. Epub 2017 Aug 1.
This pilot study assessed the diagnostic accuracy and potential impact of a rapid PCR-based screening test for the detection of group B Streptococcus (GBS) at the onset of labour for the purpose of optimising intrapartum antibiotic prophylaxis (IAP). Vaginal and rectal swabs from a convenience sample of 158 women were analysed by conventional broth-enriched culture and a rapid PCR test. Overall, GBS carriage was 18.98% by culture and 19.62% by PCR. PCR for the detection of GBS had a sensitivity of 93.1%, specificity of 96.67% and area under the curve (AUC) of 0.95. Only 19.3% GBS-positive women received IAP. Three-fourths of babies born to GBS-positive mothers did not receive surveillance for early-onset GBS disease. Of the women who received IAP, only 32.5% were GBS carriers. Seventy-four percent of the GBS-positive mothers delivered more than 5 h after recruitment, which gives adequate swab to delivery interval for appropriate antibiotic prophylaxis in labour. Impact statement What is already known about this subject: Appropriate intra-partum treatment of colonized mothers reduces the risk of GBS transmission to neonates. Universal ante partum screening of pregnant women or IAP based on risk factors in labour for GBS prevention fail to accurately identify and treat the woman who actually harbors GBS in the birth canal in labour. A PCR based rapid test, allows for real-time assessment of GBS carriage in labour.
This study highlights the fact that a large number of GBS carriers in labour, who could potentially infect their babies, do not receive IAP, and most of their babies do not receive added surveillance in the neonatal period for EOGBS disease. It also confirms that PCR testing at onset of labour is a highly sensitive and reliable test that identifies the women who are GBS carriers in labour and hence need IAP. What the implications are of these findings for clinical practice and/or further research: Timely provision of IAP for the appropriate woman is possible by adopting universal GBS screening at the onset of labor using GBS-PCR. This would involve additional costs to health care facilities and added work to laboratory personnel.
这项试点研究评估了一种基于聚合酶链反应（PCR）的快速筛查试验在分娩开始时检测B族链球菌（GBS）的诊断准确性及潜在影响，目的是优化产时抗生素预防（IAP）。对158名女性的便利样本采集阴道和直肠拭子，采用传统增菌肉汤培养法和快速PCR试验进行分析。总体而言，培养法检测GBS携带率为18.98%，PCR法为19.62%。用于检测GBS的PCR敏感性为93.1%，特异性为96.67%，曲线下面积（AUC）为0.95。仅19.3%的GBS阳性女性接受了IAP。GBS阳性母亲所生的婴儿中有四分之三未接受早发型GBS疾病监测。在接受IAP的女性中，仅32.5%是GBS携带者。74%的GBS阳性母亲在入组后5小时以上分娩，这为产时进行适当的抗生素预防提供了足够的拭子采集到分娩的间隔时间。影响声明关于该主题已有的了解：对定植母亲进行适当的产时治疗可降低GBS传播给新生儿的风险。对孕妇进行普遍产前筛查或基于产时风险因素进行IAP以预防GBS，无法准确识别和治疗分娩时产道中实际携带GBS的女性。基于PCR的快速检测可实时评估分娩时GBS携带情况。
本研究强调了这样一个事实，即大量分娩时可能感染婴儿的GBS携带者未接受IAP，且他们的大多数婴儿在新生儿期未接受早发型GBS疾病的额外监测。它还证实，分娩开始时的PCR检测是一种高度敏感且可靠的检测方法，可识别分娩时携带GBS的女性，因此这些女性需要IAP。这些发现对临床实践和/或进一步研究的意义：通过在分娩开始时采用GBS-PCR进行普遍GBS筛查，可为合适的女性及时提供IAP。这将给医疗机构带来额外成本，并给实验室人员增加工作量。
