Cost and Effectiveness of Intrapartum Group B Streptococcus Polymerase Chain Reaction Screening for Term Deliveries:

Accuracy of real-time polymerase chain reaction test for Group B Streptococcus detection in pregnant women: A systematic review and meta-analysis

OBJECTIVES

This study aimed to determine the performance of RT PCR of GBS screening in pregnant women under different situations, especially compared to different reference methods (culture or composite standards) and preprocessing before detection (directly or enrichment).

MATERIALS AND METHODS

We searched PubMed, the Cochrane Library: Cochrane Database of Systematic Reviews, EMBASE, and Google Scholar, and clinical trial registries such as ClinicalTrials.gov and WHO ICTRP until March 2024. The assessment of each study quality was performed using a modified QUADAS-2 instrument. The meta-analysis included pooled sensitivity, specificity, summary receiver operating characteristic (SROC) curve, and AUC. Publication bias was examined using Deek's funnel plot. Sensitivity analysis was conducted to evaluate the robustness of the meta-analysis. Index (I-square) and Q-test were performed to analyze the heterogeneity, and subgroup analysis and logistic meta-regression were used to identify the potential causes.

RESULTS

A total of 81 reports, including 133 research, were involved in the analysis. The pooled sensitivity and specificity of RT-PCR for detection of Group B Streptococcus in pregnant women were 96 % (95 %CI: 94 %-97 %) and 98 % (95 %CI:97 %-98 %), respectively. The pooled AUC value was 0.99 (95 %CI:0.98-1.00). In subgroup studies, there were four groups, including Group A (Enrichment & culture), Group B (Direct & culture), Group C (Enrichment & composite standard), and Group D (Direct & composite standard). Group A's pooled sensitivity and specificity were 98 % (95 %CI: 97 %-99 %) and 94 % (95 %CI:92 %-96 %), respectively. Group B's pooled sensitivity and specificity were 92 % (95 %CI: 89 %-94 %) and 96 % (95 %CI:95 %-97 %), respectively. Group C's pooled sensitivity and specificity were 98 % (95 %CI: 97 %-99 %) and 99 % (95 %CI: 99 %-99 %), respectively. Group D's pooled sensitivity and specificity were 93 %(95 %CI: 87 %-97 %) and 100 % (95 %CI:99 %-100 %), respectively. The pooled AUC values of the SROC for groups A, B, C, and D were 0.99 (95 %CI: 0.98-1.00), 0.98(95 %CI: 0.97-0.99), 1.00 (95 %CI: 0.99-1.00), and 0.99(95 %CI: 0.99-1.00), respectively.

Vaginal screening for group B streptococcus using PCR in pregnant women with unknown colonization status: Impact on newborn monitoring for early-onset sepsis

BACKGROUND

Early-onset neonatal sepsis represents a diagnostic challenge, as it is a cause of neonatal mortality and morbidity. Guidelines for the prevention of group B streptococcus (GBS) infection recommend that all pregnant women must be screened for GBS carriage at the end of pregnancy, with intrapartum antibiotic prophylaxis being provided for GBS carriers. If vaginal culture is not available, GBS polymerase chain reaction (GBS-PCR) is an alternative option for this type of screening. In our unit, GBS-PCR is performed when pregnant women present to the delivery room with ongoing labor and with no results of culture GBS screening available. The main objective of this study was to evaluate the impact of the results of GBS-PCR on monitoring modifications in newborns of mothers with unknown GBS status. The secondary objectives were to confirm the feasibility of a GBS-PCR-based screening method in everyday practice and to evaluate the impact of GBS-PCR results on the modification of intrapartum antibiotic therapy in pregnant women.

METHOD

A retrospective, single-center, observational study was conducted for 1 year. For dyads with GBS-PCR performed, changes concerning intrapartum antibiotic therapy and the newborn's monitoring were recorded. The feasibility of the method was evaluated by the delay between the GBS-PCR realization and the availability of the result; in addition, the number of GBS-PCR tests that could not be realized were collected.

RESULTS

Overall, 60 GBS-PCR samples were tested for 60 pregnant women. Results were obtained for all samples, and the median duration to obtaining the GBS-PCR results was 70 min (60.8-87.2). These results were positive for 11 (18.3 %) women and led to monitoring modifications for two infants. In total, 27 pregnant women (45 %) had modifications in their antibiotic therapy due to the GBS-PCR results.

CONCLUSION

GBS-PCR was quickly available and the results led to changes in maternal antibiotic prophylaxis and in the monitoring level of the newborns.

Benefits and harms of antenatal and newborn screening programmes in health economic assessments: the VALENTIA systematic review and qualitative investigation

Background

Health economic assessments are used to determine whether the resources needed to generate net benefit from an antenatal or newborn screening programme, driven by multiple benefits and harms, are justifiable. It is not known what benefits and harms have been adopted by economic evaluations assessing these programmes and whether they omit benefits and harms considered important to relevant stakeholders.

Objectives

(1) To identify the benefits and harms adopted by health economic assessments in this area, and to assess how they have been measured and valued; (2) to identify attributes or relevance to stakeholders that ought to be considered in future economic assessments; and (3) to make recommendations about the benefits and harms that should be considered by these studies.

Design

Mixed methods combining systematic review and qualitative work.

Systematic review methods

We searched the published and grey literature from January 2000 to January 2021 using all major electronic databases. Economic evaluations of an antenatal or newborn screening programme in one or more Organisation for Economic Co-operation and Development countries were considered eligible. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards checklist. We identified benefits and harms using an integrative descriptive analysis and constructed a thematic framework.

Qualitative methods

We conducted a meta-ethnography of the existing literature on newborn screening experiences, a secondary analysis of existing individual interviews related to antenatal or newborn screening or living with screened-for conditions, and a thematic analysis of primary data collected with stakeholders about their experiences with screening.

Results

The literature searches identified 52,244 articles and reports, and 336 unique studies were included. Thematic framework resulted in seven themes: (1) diagnosis of screened for condition, (2) life-years and health status adjustments, (3) treatment, (4) long-term costs, (5) overdiagnosis, (6) pregnancy loss and (7) spillover effects on family members. Diagnosis of screened-for condition (115, 47.5%), life-years and health status adjustments (90, 37.2%) and treatment (88, 36.4%) accounted for most of the benefits and harms evaluating antenatal screening. The same themes accounted for most of the benefits and harms included in studies assessing newborn screening. Long-term costs, overdiagnosis and spillover effects tended to be ignored. The wide-reaching family implications of screening were considered important to stakeholders. We observed good overlap between the thematic framework and the qualitative evidence.

Limitations

Dual data extraction within the systematic literature review was not feasible due to the large number of studies included. It was difficult to recruit healthcare professionals in the stakeholder's interviews.

Conclusions

There is no consistency in the selection of benefits and harms used in health economic assessments in this area, suggesting that additional methods guidance is needed. Our proposed thematic framework can be used to guide the development of future health economic assessments evaluating antenatal and newborn screening programmes.

Study registration

This study is registered as PROSPERO CRD42020165236.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127489) and is published in full in Health Technology Assessment; Vol. 28, No. 25. See the NIHR Funding and Awards website for further award information.

Prevention of Early-Onset Neonatal Group B Streptococcal Disease: A Comprehensive Review of Major Guidelines

Importance

Group B Streptococcus (GBS) colonization during pregnancy is associated with significant neonatal morbidity and mortality and represents a major public health concern, often associated with poor screening and management.

Objective

The aim of this study was to review and compare the most recently published influential guidelines on the screening and management of this clinical entity during antenatal and intrapartum periods.

Evidence Acquisition

A descriptive review of guidelines from the American College of Obstetricians and Gynecologists, the Royal College of Obstetricians and Gynecologists, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, and the Society of Obstetricians and Gynecologists of Canada on the prevention of early-onset neonatal group B streptococcal disease was carried out.

Results

There is a consensus among the reviewed guidelines regarding the optimal screening specimen type, indications for intrapartum antibiotic administration such as bacteriuria during pregnancy, clinical signs of chorioamnionitis or maternal pyrexia, and history of GBS-related neonatal disease. There is also agreement on several conditions where no intervention is recommended, that is, antepartum treatment of GBS and GBS-positive women with planned cesarean delivery and intact membranes. Controversy exists regarding the optimal screening time, with the Royal College of Obstetricians and Gynecologists stating against routine screening and on management strategies related to preterm labor and preterm prelabor rupture of membranes.

Conclusions

The development of consistent international practice protocols for the timely screening of GBS and effective management of this clinical entity both during pregnancy and the intrapartum period seems of paramount importance to safely guide clinical practice and subsequently improve neonatal outcomes.

Multicenter Performance Evaluation of the Revogene® GBS DS Real-Time PCR Assay for Group B Streptococcus Detection During Labor

PURPOSE

This study aimed to evaluate the performance and ease of use of the Revogene® GBS DS PCR assay for the intrapartum detection of Group B Streptococcus (GBS) colonization, as compared with intrapartum culture and antenatal culture-based screening.

METHODS

Between April and August 2019, 398 women who gave birth in one of the three maternities participating in this study agreed to the collection of a vaginal swab when they arrived in the labor ward. The samples were immediately sent to the adjacent laboratory where they were discharged into the buffer provided with the Revogene® GBS DS assay. Part of the buffer was used to perform the Revogene® GBS DS test, and part of the same buffer was used for GBS culture.

RESULTS

The Revogene® GBS DS assay provided a valid result in less than 70 min for 356 (89%) women. The sensitivity of the test was 85.7% (66.4-95.3%). The specificity of the test was 99.1% (97.3-99.8%). The positive predictive value was 88.9% (69.7-97.1%). The negative predictive value was 98.9% (96.9-99.6%).

CONCLUSION

The easy-to-use Revogene® GBS DS assay provides a valuable tool for the detection of GBS colonization at the beginning of labor. The sensitivity and turn-around time are adequate. The high number of invalid results needs to be addressed before the Revogene® GBS DS test can be expected to replace the current screening-based approach.

20 million pregnant women with group B streptococcus carriage: consequences, challenges, and opportunities for prevention

PURPOSE OF REVIEW

Intrapartum antibiotic prophylaxis (IAP) is currently the only recommended preventive approach against clinical consequences of maternal Group B Streptococcus (GBS) colonization. In this review, we discuss new findings of total perinatal GBS burden and relative effectiveness of differing targeting of IAP, notably microbiology-based and risk factor-based screening, including potential limitations. Finally, we provide updates on maternal GBS vaccines and their potential cost-effectiveness in disease reduction.

RECENT FINDINGS

Updated estimates of the burden of GBS related to pregnancy outcomes show (1) early-onset GBS disease incidence and deaths are high in some low- and middle-income countries where IAP has not been implemented and (2) late-onset GBS disease, preterm birth, and stillbirth, which are not preventable by IAP, remain a public health problem in both high and low-middle income settings. Observational evidence indicates that microbiology-based screening may be more effective than risk factor-based screening, but even in high-income countries, compliance is imperfect. To address the need for alternative prevention strategies, several maternal vaccine candidates are in clinical development, and modelling suggests these could be cost-effective in most scenarios.

SUMMARY

Recent progress in GBS vaccine research holds promise of reducing the large and preventable burden of mortality and disability caused by GBS disease, especially in higher-burden settings where clinical and laboratory services may be limited. Importantly vaccines also hold potential to prevent GBS stillbirths and GBS-associated preterm births.

Middle-East OBGYN Graduate Education (MOGGE) Foundation practice guidelines: prevention of group B Streptococcus infection in pregnancy and in newborn. Practice guideline no. 02-O-20

Rectovaginal colonization with group B streptococcus (GBS) is commonly encountered in pregnancy. GBS is the most common cause of early onset neonatal sepsis, which is associated with 12% case-fatality rate. Although screening protocols and prophylactic treatment are readily available worldwide, practice in low-resource countries is challenged by lack of awareness and limited implementation of these protocols. In addition, antibiotic susceptibility pattern may vary globally owing to different regulations of antibiotic prescription or prevalence of certain bacterial serotypes. This guideline appraises current evidence on screening and management of GBS colonization in pregnancy particularly in low-resource settings.

Perinatal care for the extremely preterm infant

Being born preterm (prior to 37 weeks of completed gestation) is a leading cause of childhood death up to five years of age, and is responsible for the demise of around one million preterm infants each year. Rates of prematurity, which range from approximately 5 to 18% of births, are increasing in most countries. Babies born extremely preterm (less than 28 weeks' gestation) and in particular, in the periviable (20^0/7-25^6/7 weeks) period, are at the highest risk of death, or the development of long-term disabilities. The perinatal care of extremely preterm infants and their mothers raises a number of clinical, technical, and ethical challenges. Focusing on 'micropremmies', or those born in the periviable period, this paper provides an update regarding the aetiology and impacts of periviable preterm birth, advances in the antenatal, intrapartum, and acute post-natal management of these infants, and a review of counselling/support approaches for engaging with the infant's family. It concludes with an overview of emerging technology that may assist in improving outcomes for this at-risk population.

Evaluation of the Revogene® GBS DS assay performance for the intrapartum screening of group B streptococcus in comparison with intrapartum culture

Prevention of perinatal Group B Streptococcus (GBS) transmission is crucial in our effort to prevent Early-onset GBS disease. Here, we established the performance of the Revogene GBS DS assay for the detection of group B streptococcus on intrapartum vaginal samples in a laboratory environment using a prospective noninterventional study design. Intrapartum vaginal swabs were enriched using a selective culture method which served as study reference method. Overall, 119 patients were enrolled with an antenatal and intrapartum Group B Streptococcus colonization prevalence of 12.9% and 11.8%, respectively. Compared to intrapartum culture, the Revogene GBS DS assay had a sensitivity of 92.9% and a specificity of 99.1%, while the antenatal culture displayed a sensitivity 78.6% of and specificity of 96.2%. The Revogene GBS DS assay displayed an acceptable performance according to the European Group B Streptococcus consensus recommendations. Complementary studies in clinical practice are needed to confirm these findings.

Screening-based and Risk-based Strategy for the Prevention of Early-onset Group B Streptococcus/Non-group B Streptococcus Sepsis in the Neonate: A Systematic Review and Meta-analysis

BACKGROUND

Screening-based and risk-based strategies are the 2 strategies for preventing group B streptococcus (GBS) diseases in neonates. We aimed to compare the effects of these 2 strategies in reducing the incidence of early-onset GBS sepsis (GBS-EOS) and their effects on the incidence of non-GBS sepsis.

METHODS

PubMed, Embase, Web of Science and The Cochrane Central Register of Controlled Trials were searched for the period from January 1, 1996, to December 31, 2018. Randomized controlled trials and cohort studies that compared the effects of risk-based and screening-based strategies were eligible for the meta-analysis. The I statistic was used for assessing the statistical heterogeneity across studies. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated using the random effects model.

RESULTS

There were 18 cohort studies comparing the incidence of GBS-EOS between the 2 strategies, involving a total of 604,869 newborns and 791 GBS-EOS cases. The heterogeneity across studies was moderate (I = 45%), and the pooled analysis yielded a 55% decreased risk of GBS-EOS for screening-based versus risk-based strategy (RR = 0.45; 95% CI: 0.34-0.59). For total early onset non-GBS sepsis (non-GBS-EOS), 7 studies with low heterogeneity (I = 18%) had a pooled RR of 0.91 (95% CI: 0.74-1.11), whereas for ampicillin resistant Escherichia coli-EOS, a subgroup of non-GBS-EOS, 3 studies with very low heterogeneity (I = 0%) had a pooled RR of 1.28 (95% CI: 0.74-2.21) for screening-based strategy compared with risk-based strategy.

CONCLUSIONS

Compared with risk-based strategy, screening-based prophylaxis was associated with a reduced risk of GBS-EOS.

A comparison of GenomEra® GBS PCR and GeneXpert ® GBS PCR assays with culture of GBS performed with and without broth pre-enrichment

This study was designed to compare the performance of GeneXpert® and GenomEra® group B streptococcus (GBS) PCR assays, held up against standard culture of GBS performed with and without broth pre-enrichment. In Denmark, the strategy for preventing early onset GBS infection (EOGBS) is risk factor based. Three hundred and sixty six women fulfilling one or more of the criteria for presence of risk factors for EOGBS were prospectively included. Rectovaginal swab samples were taken intrapartum and tested bed-site by the GenomEra® and the GeneXpert® GBS PCR assays and cultured at the microbiology laboratory using Granada agar plates with and without prior growth of sampling material in selective enrichment broth. Among 366 participants tested intrapartum, 99 were GBS-positive by culture, 95 by GenomEra, and 95 by GeneXpert. Compared with culture, the GenomEra and the GeneXpert performed with a sensitivity of 91.8% and 91.7% and a specificity of 98.1% and 97.3%, respectively. A combined reference standard was established by defining true positives as either culture-positive samples or culture-negative samples where both the GeneXpert and the GenomEra GBS PCR assays were positive. Using this, the sensitivity increased to 92.2% and the specificity to 99.6% for GenomEra and to 92.0% and 96.8% for GeneXpert. The use of selective broth enrichment found only three additional GBS culture-positive samples. The performance of the two PCR methods examined was very similar and close to the findings by culture, and both PCR assays are thus applicable as rapid intrapartum bed-site tests.

Intrapartum beta-lactam antibiotics for preventing group B streptococcal early-onset disease: can we abandon the concept of 'inadequate' intrapartum antibiotic prophylaxis?

Introduction: Neonatal sepsis remains a serious and potentially fatal illness. Intrapartum antibiotic prophylaxis (IAP) prevents group B streptococcal (GBS) early-onset sepsis. The optimal duration of IAP (adequate IAP) to reduce vertical transmission of GBS has been debated. Understanding the mechanism of action of IAP may help in minimizing neonatal evaluation and unnecessary antibiotic use.Areas covered: In recent years, several studies on pharmacokinetics and clinical use of IAP have been published. Although penicillin and ampicillin are the most preferred antibiotics, the clinical efficacy of non-beta-lactam antibiotics, including clindamycin and vancomycin, used in cases of penicillin anaphylaxis-associated allergy, remains debatable. This is a narrative review of the literature regarding the impact of 'inadequate' IAP on the clinical management of women and newborns.Expert opinion: Recent evidence suggests that 'inadequate' IAP with beta-lactams is more effective in preventing vertical transmission of GBS than previously thought. Newborns exposed to intrapartum beta-lactams and who are asymptomatic at birth are likely uninfected, irrespective of IAP duration before delivery. Hence, we may abandon the concept of 'inadequate' IAP with beta-lactams in early-onset GBS sepsis, relying primarily on clinical signs observed at birth for managing IAP-exposed neonates.

No. 298-The Prevention of Early-Onset Neonatal Group B Streptococcal Disease

OBJECTIVE

To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes.

OUTCOMES

Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated.

EVIDENCE

Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided.

SUMMARY STATEMENT

There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour (I). There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation.

RECOMMENDATIONS

Detection of group B Streptococcus during antenatal screening in Western Australia: a comparison of culture and molecular methods

AIM

Global screening strategies for Group B Streptococcus (GBS) include risk- or culture-based methods to guide intrapartum prophylaxis. In Western Australia (WA), antenatal culture-based screening is routine; however, numerous culture methods exist, in addition to molecular methods. We aimed to assess the comparability of research and diagnostic screening approaches.

METHODS AND RESULTS

Vaginal and rectal swabs were self-collected by pregnant women (n = 531) from King Edward Memorial Hospital, WA, in parallel to routine screening (35-37 weeks of gestation). Research methods involved culture (Strep B Carrot Broth™ and StrepB CHROMagar™) and molecular methods (real-time PCR) and were compared to routine diagnostic screening (Lim Broth and Granada agar). Overall, GBS detection was comparable between research and diagnostic approaches (3-5% discrepancy, kappa = 0·76). Specificity/sensitivity of Carrot Broth^™ was 100%/89%, while that of CHROMagar^™ was 73%/100%, respectively. Direct PCR was unable to detect GBS in ~18% of specimens which were culture positive; however, it exhibited 100% specificity.

CONCLUSIONS

This clinical evaluation of GBS screening methods provides support for current practice.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although CHROM was highly sensitive, further testing is recommended due to a high false-positive rate. Molecular assays are useful for rapid detection; however, low-titre samples may require additional enrichment prior to molecular analysis to improve sensitivity.

Streptococcus agalactiae Strains with Chromosomal Deletions Evade Detection with Molecular Methods

Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culture-positive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed four unique deletions of chromosomal DNA ranging from 181 bp to 49 kb. Prospective surveillance studies demonstrated that the prevalence of GBS isolates containing deletions in the convenience sample was <1% in three geographic locations but 7% in a fourth location. Among the 15 isolates with chromosomal deletions, multiple pulsed-field gel electrophoresis types were identified, one of which appears to be broadly dispersed across the United States.

Selective or universal screening for GBS in pregnancy (review)

Group B streptococcus (GBS) is the most common cause of early-onset neonatal sepsis in many countries and responsible for significant perinatal morbidity and mortality worldwide. Intrapartum antibiotic prophylaxis has been the mainstay of efforts to prevent early-onset GBS disease in recent decades, however it is unclear if women should be targeted based on the presence of clinical risk factors or by screening for GBS colonisation during pregnancy. Universal bacteriological screening of women in late pregnancy has been widely adopted but questions remain regarding its benefits and potential harms. Newer approaches to screening based on rapid point-of-care testing require further evaluation in randomised controlled trials to inform evidence-based practice. Given current preventive strategies do not protect against late onset disease and other sequelae of infection, maternal vaccination against GBS may present the best opportunity to reduce the global burden of invasive GBS disease in the future.

Comparison of qPCR and culture methods for group B Streptococcus colonization detection in pregnant women: evaluation of a new qPCR assay

BACKGROUND

Streptococcus Group B (GBS) colonization in pregnant women is the most important risk factor for newborn disease due to vertical transmission during delivery. GBS colonization during pregnancy has been implicated as a leading cause of perinatal infections. Traditionally, pregnant women are screened for GBS between 35 and 37 weeks of gestation. However, antenatal culture-based screening yields no information on GBS colonization status and offers low predictive value for GBS colonization at delivery. Numerous assays have been evaluated for GBS screening in an attempt to validate a fast and efficient method. The aim of this study was to compare bacteria isolation by culture and two qPCR techniques, targeting sip and cfb genes, respectively, for detecting colonizing GBS.

METHODS

Cultures - the gold-standard technique, a previous qPCR technique targeting the sip gene, and a new proposed qPCR assay targeting the cfb gene were evaluated as diagnostic tools on 320 samples.

RESULTS

Considering cultures as the gold standard, the evaluated qPCR method detected 75 out of 78 samples, representing a sensitivity of 93.58% (95% confidence interval (CI), 90.89-96.27) and specificity of 94.62% (95% CI, 91.78-97.46). However, an additional analysis was performed for true positives that included not only samples showing positives by culture but samples showing positive for both qPCR assays. The sensitivity and specificity were recalculated including these discrepant samples and a total of 89 samples were considered as positive, giving a prevalence of 27.81%. With this new analysis, the qPCR targeting the cfb gene showed a sensitivity of 95.5% (95% CI, 88.65-98.59) and specificity of 99.13% (95% CI, 96.69-99.97).

CONCLUSIONS

The new qPCR method is a sensitive and specific assay for detecting GBS colonization and represents a valuable tool for identifying candidates for intrapartum antibiotic prophylaxis. Cultures should be retained as the reference and the routine technique because of its specificity and cost analysis ratio, but it would be convenient to introduce PCR techniques to check negative culture samples or when an urgent detection is required to reduce risk of infection among infants.

Group B streptococcal colonization in mothers and infants in western China: prevalences and risk factors

BACKGROUND

The epidemiology of maternal and infant Group B streptococcus (GBS) colonization is poorly understood in China. The aim of this study is to explore the prevalence and risk factors associated with maternal and infant GBS colonization in Western China.

METHODS

From January 2017 to June 2017, a prospective study was conducted to estimate the maternal and infant GBS colonization rate by maternal rectovaginal and infant nasopharynx, ear canal and umbilical swab culture. Patient demographics, clinical characteristics and outcomes were collected. Chi-square and logistic regression analyses were used to examine the risk factors associated with GBS colonization of mothers and infants.

RESULTS

The GBS colonization rate in mothers and infants was 6.1 and 0.7%, respectively. The vertical transmission rate was 7.6%. The early onset GBS infection rate was 0.58 per 1000 live births and mortality was 0.29 per 1000 live births. Age younger than 40 years (p = 0.040) and minority ethnic status (p = 0.049) were associated with higher GBS colonization rate in pregnant women. Positive GBS status in the mother prior to delivery (p < 0.001) as well as longer duration of membrane rupture (≥12 h) (p < 0.001) and longer labor (≥4 h) (p < 0.001) were all significant risk factors for GBS colonization in infants. Compared to infants without GBS colonization, infants colonized with GBS were more likely to have had a temperature of ≥38 °C (p < 0.001), developed early onset infection (EOD) (p < 0.001), and been prescribed antibiotics (p < 0.001). Furthermore, infants with GBS were more likely to have been admitted to neonatal intensive unit (NICU) (p < 0.001) with a longer hospital length of stay (LOS) (p < 0.001).

CONCLUSIONS

Maternal GBS colonization, longer duration of membrane rupture and labor were all major risk factors associated with GBS colonization in Chinese infants. Infant GBS colonization was associated with increased risk of EOD and NICU admission as well as longer LOS.

Vaginal antiseptics reduce the risk of perinatal infection with group B streptococci

OBJECTIVE

To evaluate the efficacy and safety of dequalinium chloride (DQC; 10 mg vaginal tablets), administered shortly prior to delivery in women with group B streptococcus (GBS) infection.

METHODS

This observational, longitudinal, and prospective study involved 201 pregnant women at term, potentially carriers of GBS bacteria, scheduled for induction with oxytocin and with no premature rupture of amniotic membranes.

RESULTS

A total of 163 women (81.09%) tested positive for GBS in their first vaginal swab (pre-DQC administration). In their second swab, post-DQC administration, 48 women were positive (23.88%) and 153 (76.12%) were negative. The number of GBS-colonized women after the administration of DQC was reduced by 57.21%. In the third swab, postpartum, 57 women were positive (28.35%). None of the newborns were positive for GBS in the oropharynx swab. The median DQC exposure time was 9.98 hours. Adverse events associated with the prophylactic treatment were reported in five women (vulvovaginal irritation).

CONCLUSIONS

The administration of a single vaginal tablet of 10 mg DQC the day before induction reduced the number of GBS-colonized women by 57.21%, causing no maternal and perinatal adverse events.

Intrapartum group B Streptococcus screening in the labor ward by Xpert® GBS real-time PCR

Group B Streptococcus (GBS) is the leading cause of neonatal infections in industrialized countries. Intrapartum antibiotic prophylaxis (IAP) given to colonized parturients is a key step for the prevention of neonatal early-onset infection. We compared the performances of Xpert® GBS polymerase chain reaction (PCR) (Cepheid, Sunnyvale, CA, USA) as a point-of-care system in labor wards to standard culture for intrapartum GBS detection. Pregnant women with a GBS-positive antenatal screening were prospectively included. A vaginal double swab was collected at the time of delivery for point-of-care Xpert® GBS PCR and GBS culture. A total of 565 pregnant women were included. Valid Xpert® GBS results were obtained for 488 (86.4%) women on the first attempt. Repeat testing improved the PCR success to 516 (91.3%) women. Among the 305 women positive for GBS by culture at delivery, only 238 (78.0%) were positive by Xpert® GBS PCR, cycle thresholds being correlated to culture quantification. Among 260 women negative for GBS culture, 56 (21.5%) were positive by Xpert® GBS PCR, including 50 where IAP was initiated before vaginal sampling. Overall, among the 565 women with GBS antenatal positive culture, only 335 (59.3%) were still positive at delivery whatever the technique used, resulting in unnecessary IAP for 40% of them. This large cohort study comparing intrapartum to antepartum GBS detection provides evidence that (i) Xpert® GBS PCR might be a valuable solution for intrapartum GBS detection compared to culture-based strategies and (ii) laboratory training of non-specialized staff is mandatory to reach the performances required for point-of-care tests.

Erythromycin or Clindamycin - is it Still an Empirical Therapy against Streptococcus agalactiae in Patients Allergic to Penicillin?

Retrospective analysis of Streptococcus agalactiae antibiotic susceptibility isolated in 2010-2013 was performed. Penicillin was still the first-line antibiotic. Due to the high percentage of strains resistant to erythromycin and clindamycin empirical treatment with these antibiotics may not be effective. Lower resistance rate to erythromycin and clindamycin among strains isolated from infected pregnant women and newborns were observed than among strains isolated from samples from patients hospitalized in other departments (29% and 47% v. 46% and 63%). The increasing resistance rate might give a rise to a new epidemiological situation.

Risk factors for group B streptococcal disease in neonates of mothers with negative antenatal testing

OBJECTIVE

The aim of this study was to identify risk factors for early-onset group B Streptococcus (EOGBS) disease in neonates of mothers with negative antenatal screening.

STUDY DESIGN

We performed a retrospective cohort study of neonates born to mothers with negative antenatal GBS screening between 2002 and 2012. Our primary outcome was EOGBS infection. We used multivariable logistic regression to assess factors associated with EOGBS.

RESULTS

EOGBS was confirmed in 492 of the 179 818 neonates that met the study inclusion criteria. Risk factors for EOGBS included black race (reference: white, odds ratio (OR) =1.81 (95% confidence interval: 1.43, 2.31)), maternal age <18 years (reference: >35 years, OR=2.63 (1.54, 4.51)) and maternal age 18 to 35 years (reference: >35 years, OR=1.94 (1.30, 2.88)).

CONCLUSION

Maternal age <18 years and black race were the strongest predictors of EOGBS. Further research investigating contributors to the discordance between screening results and neonatal outcomes in these populations is needed.

Prévention de l'infection néonatale à streptocoques du groupe B d'apparition précoce

OBJECTIF

Analyser les données issues de la littérature et formuler des recommandations sur la prise en charge des parturientes en vue de prévenir l'infection néonatale à streptocoques du groupe B d'apparition précoce. Parmi les révisions clés que renferme la présente directive clinique mise à jour, on trouve des modifications quant aux recommandations en ce qui concerne les schémas posologiques d'antibioprophylaxie, les épreuves de sensibilité et la prise en charge des femmes présentant une rupture prématurée des membranes.

ISSUES

Parmi les issues maternelles évaluées, on trouvait l'exposition aux antibiotiques au cours de la grossesse et du travail, ainsi que les complications associées à l'administration d'antibiotiques. Les issues néonatales associées aux taux d'infection néonatale à streptocoques du groupe B d'apparition précoce ont été évaluées. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, CINAHL et The Cochrane Library entre janvier 1980 et juillet 2012, au moyen d'un vocabulaire contrôlé et de mots clés appropriés (« group B streptococcus », « antibiotic therapy », « infection », « prevention »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en mai 2013. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales.

VALEURS

La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). AVANTAGES, DéSAVANTAGES ET COûTS: Les recommandations que renferme la présente directive clinique sont conçues de façon à aider les cliniciens à identifier et à assurer la prise en charge des grossesses exposées à un risque d'infection néonatale à streptocoques du groupe B, en vue d'optimiser les issues maternelles et périnatales. Aucune analyse de rentabilité n'est fournie. DéCLARATION SOMMAIRE: Nous disposons de bonnes données (issues d'essais comparatifs randomisés) indiquant que, chez les femmes présentant une rupture prématurée des membranes à terme qui sont colonisées par des streptocoques du groupe B, le déclenchement du travail entraîne une baisse des taux d'infection néonatale. (I) Aucune donnée ne permet de soutenir que, dans une telle situation clinique, la prise en charge non interventionniste permet l'obtention de bonnes issues néonatales. RECOMMANDATIONS.

The Prevention of Early-Onset Neonatal Group B Streptococcal Disease

OBJECTIVE

To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes.

OUTCOMES

Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated.

EVIDENCE

Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided.

SUMMARY STATEMENT

There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour (I). There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation.

RECOMMENDATIONS

Group B Streptococci Screening Before Repeat Cesarean Delivery: A Cost-Effectiveness Analysis

OBJECTIVE

To estimate the cost-effectiveness of universal group B streptococci (GBS) screening in women with a singleton pregnancy planning a repeat cesarean delivery.

METHODS

We conducted a decision analysis from a health care perspective to compare the cost-effectiveness of GBS screening for women planning a repeat cesarean delivery. With universal screening, all GBS-positive women who labored before a scheduled cesarean delivery received antibiotic prophylaxis. With no screening, women who presented in labor received antibiotics based on risk-based criteria. Neonates born to women colonized with GBS were at risk for early-onset GBS disease, disability, and death. We assumed a GBS prevalence of 25%, that 26.6% of women labored between 35 weeks of gestation and their scheduled time for cesarean delivery, and that 3.3% who planned a repeat cesarean delivery instead delivered vaginally. The primary outcome was cost per neonatal quality-adjusted life-year gained, with a cost-effectiveness threshold of $100,000 per quality-adjusted life-year. Neonatal quality of life was assessed using five health states (healthy, mild, moderate, or severe disability, and death) with a life expectancy of 79 years for healthy neonates. One-way sensitivity and Monte Carlo analyses were used to evaluate the results.

RESULTS

In the base case, universal GBS screening in women planning a repeat cesarean delivery was not cost-effective compared with no screening, costing $114,445 per neonatal quality-adjusted life-year gained. The cost to prevent an adverse outcome from GBS exceeded $400,000. If greater than 28% of women were GBS-positive, greater than 29% labored before their scheduled delivery, or greater than 10% delivered vaginally, universal screening became cost effective.

CONCLUSION

Universal GBS screening in women with a singleton pregnancy planning a repeat cesarean delivery may not be cost-effective in all populations. However, in populations with a high GBS prevalence, women at high risk of laboring before their scheduled cesarean delivery, or women who may ultimately opt for a vaginal delivery, GBS screening may be cost effective.

Group B streptococcal infections in the newborn infant and the potential value of maternal vaccination

Group B Streptococcus (GBS) is a leading cause of neonatal bacterial infections in developed countries. Early-onset disease (EOD) occurs at day 0-6 and late-onset disease occurs at day 7-89. Currently, the prevention of EOD relies upon intrapartum antibiotic prophylaxis (IAP) given to women who are GBS positive at prenatal screening or women with risk factors for EOD. Although successfully implemented, IAP has not fully eradicated EOD, and incidence rates of late-onset disease remain unchanged. Furthermore, antibiotic resistance may result from widespread antibiotic use. New prophylactic strategies are therefore of critical importance. A vaccine active against GBS, administered during pregnancy and combined with targeted IAP, could overcome these problems and reduce the mortality and morbidity associated with invasive diseases.

Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

Intrapartum group B Streptococcus screening using real-time polymerase chain reaction in Japanese population

OBJECTIVE

The objective of this study was to analyze the diagnostic accuracy of a commercial real-time polymerase chain reaction (PCR) assay for group B streptococcus (GBS) colonization status and to compare results of the intrapartum PCR with the antepartum conventional GBS culture in Japanese pregnant women.

METHODS

This prospective observational study enrolled Japanese pregnant women at 35-37 weeks' gestation. Paired recto-vaginal swabs were obtained for PCR and conventional culture, both at 35-37 weeks' gestation and at admission for delivery. Performance of PCR was analyzed by comparing with the culture results. Furthermore, using the intrapartum culture results as the gold standard, the test of both the antepartum culture and the intrapartum PCR were characterized.

RESULTS

We prospectively enrolled 79 pregnant women at 35-37 weeks' gestation, and the intrapartum results were obtained from 73 of those women. The sensitivity of PCR was 86.2%, and concordance rate with the conventional culture was 96.7% overall. Compared with the intrapartum culture, the sensitivity and the specificity of the intrapartum PCR were 83.3% and 98.4%, respectively, while the sensitivity and the specificity of the antepartum culture were 100.0% and 95.1%.

CONCLUSIONS

The intrapartum real-time PCR assay for GBS screening has the accuracy similar to the antepartum conventional culture method.

Multicenter clinical evaluation of the Xpert GBS LB assay for detection of group B Streptococcus in prenatal screening specimens

Neonatal infection with Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis and meningitis in newborns. Recent guidelines have recommended universal screening of all pregnant women to identify those colonized with GBS and administration of peripartum prophylaxis to those identified as carriers to reduce the risk of early-onset GBS disease in neonates. Enriched culture methods are the current standard for prenatal GBS screening; however, the implementation of more sensitive molecular diagnostic tests may be able to further reduce the risk of early-onset GBS infection. We report a clinical evaluation of the Xpert GBS LB assay, a molecular diagnostic test for the identification of GBS from broth-enriched vaginal/rectal specimens obtained during routine prenatal screening. A total of 826 specimens were collected from women undergoing prenatal screening (35 to 37 weeks' gestation) and tested at one of three clinical centers. Each swab specimen was tested directly prior to enrichment using the Xpert GBS assay. Following 18 to 24 h of broth enrichment, each specimen was tested using the Xpert GBS LB assay and the FDA-cleared Smart GBS assay as a molecular diagnostic comparator. Results obtained using all three molecular tests were compared to those for broth-enriched culture as the gold standard. The sensitivity and specificity of the Xpert GBS LB assay were 99.0% and 92.4%, respectively, compared to those for the gold standard culture. The Smart GBS molecular test demonstrated sensitivity and specificity of 96.8% and 95.5%, respectively. The sensitivities of the two broth-enriched molecular methods were superior to those for direct testing of specimens using the Xpert GBS assay, which demonstrated sensitivity and specificity of 85.7% and 96.2%, respectively.

Antibiotic use and misuse during pregnancy and delivery: benefits and risks

Although pregnancy is considered as a physiological state, most pregnant women in developed countries receive multiple medications to prevent maternal or neonatal complications, with antibiotics among the most frequently prescribed. During pregnancy, antibiotics are often prescribed in the context of preterm labor, intrapartum fever, prevention of neonatal Group B Streptococcus fever, and cesarean section. Outside this period, they are commonly prescribed in the community setting for respiratory, urinary, and ear, nose and throat infection symptoms. Whereas some of the current indications have insightful reasons to justify their use, potential risks related to overuse and misuse may surpass the benefits. Of note, the recent 2014 World Health Assembly expressed serious concern regarding antibiotic resistance due to antibiotic overuse and misuse and urged immediate action to combat antibiotic resistance on a global scale. Most studies in the obstetrics field have focused on the benefits of antibiotics for short-term maternal and neonatal complications, but with very little (if any) interest in long-term consequences.

Molecular-based screening for perinatal group B streptococcal infection: implications for prevention and therapy

Group B streptococci (GBS) are a leading cause of infectious neonatal morbidity and mortality. Timely and accurate identification of colonized pregnant women is imperative to implement intrapartum antibioprophylaxis (IAP) to reduce the risk of early neonatal sepsis. Current guidelines recommend screening for GBS carriage with vaginal-rectal cultures. However, cultures require 24-72 h, thus precluding their use for intrapartum screening and these are only performed at 35-37 weeks gestation. New rapid molecular-based tests can detect GBS within hours. They have the potential to be used intrapartum and to allow for selective IAP in women carrying GBS. An advantage is that they can sometimes be performed by non-laboratory staff in the labor suite, thus avoiding delays in sample transfers to the microbiology laboratory. Another possible use of molecular-based assays is for the diagnosis of neonatal sepsis, where tests with a short turnaround time and high sensitivity and specificity are crucial. In this situation, the detection of microorganisms once antibiotic therapy has already been started is important, as treatment is started immediately once sepsis is suspected without waiting for microbiological confirmation. In this article, we discuss the state-of-the-art molecular-based tests available for GBS screening during pregnancy, as well as their implications for IAP for the diagnosis and prevention of neonatal sepsis.

Group B streptococcal epidemiology and vaccine needs in developed countries

Development of a group B streptococcal vaccine (GBS) vaccine is the most promising approach for the prevention of GBS infections in babies, given the potential adverse effects of intrapartum antibiotic prophylaxis as well as the need for effective prevention of both adult and late perinatal disease. There are numerous prevention strategies at this time but none are 100% effective in the eradication of neonatal early onset GBS disease and there are no preventative strategies for late onset disease. The need for a GBS vaccine is therefore, of utmost importance. Efforts applying genomics to GBS vaccine development have led to the identification of novel vaccine candidates. The publication of GBS whole genomes coupled with new technologies including multigenome screening and bioinformatics has also allowed researchers to overcome the serotype limitation of earlier vaccine preparations in the search of a universal effective vaccine against GBS. This review brings together the key arguments concerning the potential need of a GBS vaccine in developed countries and describes the current status with GBS epidemiology and microbiology in these countries.

Evaluation of the new brilliance GBS chromogenic medium for screening of Streptococcus agalactiae vaginal colonization in pregnant women

Three commercial chromogenic agar media were evaluated for Streptococcus agalactiae screening in 200 vaginal swabs from pregnant women. The sensitivity and specificity were 94.3% and 100% for Granada medium (bioMérieux), 100% and 90.3% for Brilliance GBS medium (Thermo Fisher Scientific), and 100% and 98.8% for ChromID STRB medium (bioMérieux), respectively.

The prevention of early-onset neonatal group B streptococcal disease

OBJECTIVE

To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes.

OUTCOMES

Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated.

EVIDENCE

Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided.

SUMMARY STATEMENT

There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour. (I) There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation.

RECOMMENDATIONS

1. Offer all women screening for colonization with group B streptococcus at 35 to 37 weeks' gestation with culture taken from one swab first to the vagina and then to the rectum (through the anal sphincter). (II-1A) This includes women with planned Caesarean delivery because of their risk of labour or ruptured membranes earlier than the scheduled Caesarean delivery. (II-2B) 2. Because of the association of heavy colonization with early onset neonatal disease, provide intravenous antibiotic prophylaxis for group B streptococcus at the onset of labour or rupture of the membranes to: • any woman positive for group B streptococcus by vaginal/rectal swab culture screening done at 35 to 37 weeks' gestation (II-2B); • any woman with an infant previously infected with group B streptococcus (II-3B); • any woman with documented group B streptococcus bacteriuria (regardless of level of colony-forming units) in the current pregnancy. (II-2A) 3. Manage all women who are < 37 weeks' gestation and in labour or with rupture of membranes with intravenous group B streptococcus antibiotic prophylaxis for a minimum of 48 hours, unless there has been a negative vaginal/rectal swab culture or rapid nucleic acid-based test within the previous 5 weeks. (II-3A) 4. Treat all women with intrapartum fever and signs of chorioamnionitis with broad spectrum intravenous antibiotics targeting chorioamnionitis and including coverage for group B streptococcus, regardless of group B streptococcus status and gestational age. (II-2A) 5. Request antibiotic susceptibility testing on group B streptococcus-positive urine and vaginal/rectal swab cultures in women who are thought to have a significant risk of anaphylaxis from penicillin. (II-1A) 6. If a woman with pre-labour rupture of membranes at ≥ 37 weeks' gestation is positive for group B streptococcus by vaginal/rectal swab culture screening, has had group B streptococcus bacteriuria in the current pregnancy, or has had an infant previously affected by group B streptococcus disease, administer intravenous group B streptococcus antibiotic prophylaxis. Immediate obstetrical delivery (such as induction of labour) is indicated, as described in the Induction of Labour guideline published by the Society of Obstetricians and Gynaecologist in September 2013. (II-2B) 7. At ≥ 37 weeks' gestation, if group B streptococcus colonization status is unknown and the 35- to 37-week culture was not performed or the result is unavailable and the membranes have been ruptured for greater than 18 hours, administer intravenous group B streptococcus antibiotic prophylaxis. (II-2B) 8. If a woman with pre-labour rupture of membranes at < 37 weeks' gestation has an unknown or positive group B streptococcus culture status, administer intravenous group B streptococcus prophylaxis for 48 hours, as well as other antibiotics if indicated, while awaiting spontaneous or obstetrically indicated labour. (II-3B).

Reduction of the use of antimicrobial drugs following the rapid detection of Streptococcus agalactiae in the vagina at delivery by real-time PCR assay

OBJECTIVE

To assess whether the determination of the presence of group B streptococci (GBS) in the vagina using a rapid polymerase chain reaction (PCR) assay at delivery was able to spare useless antimicrobial treatments, as compared with conventional culture at 34-38 weeks of gestation.

DESIGN

Practical evaluation and prospective cost-effectiveness analysis.

SETTING

A university hospital in France.

POPULATION

A cohort of 225 women in labour at the University-Hospital of Saint-Etienne.

METHODS

Each woman had a conventional culture performed at 34-38 weeks of gestation. At the beginning of labour, two vaginal swabs were sampled for rapid PCR testing and culture. The decision to prescribe a prophylactic antimicrobial treatment or not was taken according to the result of the PCR test. A comparative cost-effectiveness analysis of the two diagnostic strategies was carried out.

MAIN OUTCOME MEASURES

Number of women receiving inadequate prophylactic antimicrobial drugs following each testing strategy, costs of PCR testing and culture, frequency of vaginal GBS, and diagnostic performance of the PCR test at delivery.

RESULTS

The percentage of unnecessarily treated women was significantly reduced using the rapid test versus conventional culture (4.5 and 13.6%, respectively; P < 0.001). The rate of vaginal GBS at delivery was 12.5%. The incremental cost-effectiveness ratio (ICER) for each inadequate management avoided was €36 and €173 from the point of view of the healthcare system and hospital, respectively.

CONCLUSIONS

The PCR assay reduced the number of inadequate antimicrobial treatments aimed to prevent the early onset of GBS disease. However, this strategy generates extra costs that must be put into balance with its clinical benefits.

Evaluation of the Cepheid Xpert GBS assay for rapid detection of group B Streptococci in amniotic fluids from pregnant women with premature rupture of membranes

The Xpert GBS real-time PCR assay for the detection of group B streptococci (GBS) in antepartum screening samples was evaluated on amniotic fluid samples collected from 139 women with premature rupture of membrane at term. When any intrapartum positive result from the Xpert GBS or culture was considered a true positive, the sensitivities of the Xpert GBS and culture were 92.3% and 84.6%, respectively. This assay could enhance exact identification of candidates for intrapartum antibiotic prophylaxis.