Effectiveness of Intrapartum Antibiotic Prophylaxis for Prevention of Early-Onset Group B Streptococcal Disease

Group B Streptococcus and Intraamniotic Inflammation and Infection

Intraamniotic inflammation and infection complicate 2% to 5% of term deliveries. Group B Streptococcus (GBS) is a common cause of intraamniotic infection associated with invasive neonatal disease and maternal morbidity. Universal vaginal-rectal screening for GBS colonization is recommended between 36 and 37 weeks. Intrapartum antibiotic prophylaxis is recommended for individuals with positive GBS screens and other risk factors. Intravenous penicillin is the preferred antimicrobial agent. Individuals with penicillin allergies may receive cefazolin for low-risk allergies and either clindamycin or vancomycin for high-risk allergies, depending on their antimicrobial susceptibilities. Clinical trials are underway to evaluate the safety and immunogenicity of maternal anti-GBS vaccine candidates.

Timing and dosage of intrapartum prophylactic penicillin for preventing early-onset group B streptococcal disease: assessing maternal and umbilical cord blood concentration

OBJECTIVE

Timing of administration of antibiotics and concentrations in maternal blood and the umbilical cord blood are important prerequisites for optimal intrapartum antibiotic prophylaxis (IAP) of neonatal early-onset group B streptococcus (GBS) disease. This cohort study aimed to explore penicillin concentrations in mothers and infants at birth in relation to time elapsed from administration to delivery and to the minimal inhibitory concentration (MIC) for GBS.

MAIN OUTCOME MEASURES

Penicillin G concentrations in maternal and umbilical cord blood in relation to time and dose from administration to time of delivery.

RESULTS

In 44 mother-infant dyads, median maternal penicillin G concentration was 0.2 mg/L (IQR 0-0.8 mg/L; range 0-1.6 mg/L). Median infant penicillin G concentration was 1.2 mg/L (IQR 0.5-5.0 mg/L; range 0-12.7 mg/L). In all infants (N=38) born less than 4 hours after the latest IAP administration, penicillin G concentrations far exceeded MIC (0.125 mg/L), even after short time intervals between IAP administration and birth. The highest plasma concentrations were reached in umbilical cord blood within 1 hour from IAP administration to birth.For 44 mother-infant dyads, maternal concentrations were very low compared with their infants'; particularly, very high concentrations were seen in the 20 infants with only one dose of IAP.

CONCLUSION

High concentrations of penicillin G were found in umbilical cord blood of infants born less than 4 hours after IAP administration, well above the MIC for GBS.

Membrane stripping in group B streptococcus carriers does not impede adequate intrapartum antibiotic prophylaxis: a retrospective study

Objective

Membrane stripping in group B streptococcus (GBS) carriers poses an increased risk of inadequate antibiotic prophylaxis, potentially due to accelerated labor, thereby potentially impacting the management of GBS colonization during delivery. We compared the adequacy of intrapartum antibiotic prophylaxis between pregnant women colonized with GBS, who underwent membrane stripping and those who did not. The study aimed to determine whether the performance of membrane stripping, by potentially shortening labor duration, increases the risk of inadequate antibiotic prophylaxis dispensation.

Study design

A retrospective cohort study was conducted on GBS screen-positive women with a full-term singleton pregnancy in cephalic presentation, who were eligible for vaginal delivery. The exposed group consisted of women who underwent membrane stripping, while the unexposed group consisted of women who did not undergo membrane stripping. The primary outcome was defined as inadequate duration of antibiotic prophylaxis during labor, wherein less than 4 h of beta-lactam antibiotics were administered prior to delivery. Neonatal outcome was compared between the groups.

Results

This retrospective cohort study comprised 1,609 women, with 129 in the exposed group (stripping group) and 1,480 in the unexposed group (no stripping group). Adequate intrapartum antibiotic prophylaxis was received by 64.3% (83/129) of the exposed group, compared to 46.9% (694/1,480) of the unexposed group (p = 0.003). Membrane stripping was associated with increased odds of receiving adequate prophylaxis (OR 1.897, 95% CI 1.185-3.037, p = 0.008). After excluding women who presented to the labor ward in active labor and delivered in less than 4 h, both the exposed and unexposed groups had similarly high rates of adequate intrapartum antibiotic prophylaxis (87.5% vs. 85.8%, respectively). No significant difference was observed in adverse neonatal outcomes between the groups.

Conclusion

The provision of membrane stripping did not impede adequate intrapartum antibiotic prophylaxis and was correlated with a higher rate of sufficient prophylaxis in comparison to non-swept patients. These observations suggest that membrane stripping can be considered a safe option for ensuring adequate antibiotic prophylaxis in women colonized with GBS.

Cefazolin as the mainstay for antibiotic prophylaxis in patients with a penicillin allergy in obstetrics and gynecology

Cefazolin is the most common antibiotic used for prophylaxis in obstetrics and gynecology. Among those with a penicillin allergy, alternative antibiotics are often chosen for prophylaxis, given fears of cross-reactivity between penicillin and cefazolin. Alternative antibiotics in this setting are associated with adverse sequelae, including surgical site infection, induction of bacterial resistance, higher costs to the healthcare system, and possible Clostridium difficile infection. Given the difference in R1 side chains between penicillin and cefazolin, cefazolin use is safe and should be recommended for patients with a penicillin allergy, including those who experience Immunoglobulin E-mediated reactions such as anaphylaxis. Cefazolin should only be avoided in those who experience a history of a severe, life-threatening delayed hypersensitivity reaction manifested as severe cutaneous adverse reactions (Steven-Johnson Syndrome), hepatitis, nephritis, serum sickness, and hemolytic anemia in response to penicillin administration. In addition, >90% of those with a documented penicillin allergy do not have true allergies on skin testing. Increased referral for penicillin allergy testing should be incorporated into routine obstetric care and preoperative assessment to reduce suboptimal antibiotic prophylaxis use. More education is needed among providers surrounding penicillin allergy assessment and cross-reactivity among penicillins and cephalosporins to optimize antibiotic prophylaxis in obstetrics and gynecology.

Neonatal Group B Streptococcus Disease

Group B Streptococcus (GBS) is an important cause of neonatal sepsis in term and preterm infants. Because GBS colonizes human genitourinary and gastrointestinal tracts, a significant focus of neonatal GBS disease prevention is to interrupt vertical transmission of GBS from mother to infant during parturition. Routine antepartum GBS screening in pregnant women, as well as widespread use of intrapartum antibiotic prophylaxis, have aided in overall reductions in neonatal GBS disease during the past 3 decades. However, neonatal GBS disease persists and may cause mortality and significant short- and long-term morbidity among survivors. Herein, we highlight contemporary epidemiology, microbial pathogenesis, and the clinical presentation spectrum associated with neonatal GBS disease. We summarize obstetric recommendations for antenatal GBS screening, indications for intrapartum antibiotic prophylaxis, and considerations for antibiotic selection. Finally, we review national guidelines for risk assessment and management of infants at risk for GBS disease.

Prevalence of early neonatal sepsis and positive maternal culture for group B beta-hemolytic Streptococcus

OBJECTIVE

The aim of this study was to evaluate the prevalence of early neonatal sepsis in pregnant women with a positive culture for group B beta-hemolytic Streptococcus in a middle-income city in Southeastern Brazil.

METHODS

A retrospective cohort study was conducted, involving singleton low- and high-risk pregnancies in whom group B beta-hemolytic Streptococcus cultures were evaluated between 35 and 37 weeks of gestation using vaginal and anal swabs. A specific medium (Todd-Hewitt) was used for culturing. The pregnant women were divided into two groups based on positive (n==201) and negative (n==420) cultures for group B beta-hemolytic Streptococcus.

RESULTS

The maternal colonization rate by group B beta-hemolytic Streptococcus was 32.3%. The prevalence of early neonatal sepsis was 1.0% (2/201) among patients with a positive group B beta-hemolytic Streptococcus culture and 1.9% (8/420) among patients with a negative culture. Among the patients who underwent adequate prophylaxis, crystalline penicillin G was used in 51.9% (54/104), followed by cefazolin in 43.3% (45/104), ampicillin in 3.8% (4/104), and clindamycin in 1.0% (1/104). A model that included prematurity (p==0.001) proved to be an independent risk predictor of early neonatal sepsis [χ2 (1)==15.0, odds ratio: 16.9, 95% confidence interval: 4.7-61.6, p<0.001, Nagelkerke R2==0.157].

CONCLUSION

The prevalence of a positive culture for group B beta-hemolytic Streptococcus was high. However, the prevalence of early neonatal sepsis was low in pregnant women with both positive and negative group B beta-hemolytic Streptococcus cultures and in pregnant women with a positive culture who underwent both adequate and inadequate antibiotic prophylaxis. Prematurity proved to be an independent predictor of early neonatal sepsis, considering the entire study population.

Group B Streptococcus rectovaginal colonization screening on term pregnancies: culture or polymerase chain reaction?

OBJECTIVES

The aim of this study was to evaluate if screening Group B Streptococcus colonization by intrapartum polymerase chain reaction could improve intrapartum administration of antibiotic prophylaxis, compared with antepartum culture screening and analyze the sensitivity and specificity of polymerase chain reaction test.

METHODS

198 pregnant women with Group B Streptococcus colonization antepartum culture screening were included. When they arrived at hospital for delivery, two rectovaginal swabs were collected: for culture and polymerase chain reaction method.

RESULTS

The rate of Group B Streptococcus colonization antepartum detected by culture was 16.7%; at delivery was 17.2% when detected by culture and 19.7% using polymerase chain reaction method. The rate of inconclusive polymerase chain reaction tests was 0.5%. Considering intrapartum culture screening as gold standard, sensitivity and specificity of polymerase chain reaction test for intrapartum Group B Streptococcus colonization was 97.1% and 95.7%, respectively. The global rate of discordance between antepartum and intrapartum Group B Streptococcus colonization was 6.6%. The rate of women not treated with intrapartum antibiotic prophylaxis in the setting of positive intrapartum culture was significantly lower using intrapartum polymerase chain reaction test (0.5%) than with antepartum culture method (3.5%, p = 0.035).

CONCLUSION

The use of intrapartum antibiotic prophylaxis can be more efficient when screening Group B Streptococcus colonization intrapartum by polymerase chain reaction test. Polymerase chain reaction method had a good performance in our study, with high sensitivity and specificity.

Early-onset group B streptococcal disease in African countries and maternal vaccination strategies

Invasive group B streptococcal (GBS) disease is the commonest perinatally-acquired bacterial infection in newborns; the burden is higher in African countries where intrapartum antibiotic prophylaxis strategies are not feasible. In sub-Saharan Africa, almost one in four newborns with GBS early-onset disease will demise, and one in ten survivors have moderate or severe neurodevelopmental impairment. A maternal GBS vaccine to prevent invasive GBS disease in infancy is a pragmatic and cost-effective preventative strategy for Africa. Hexavalent polysaccharide protein conjugate and Alpha family surface protein vaccines are undergoing phase II clinical trials. Vaccine licensure may be facilitated by demonstrating safety and immunological correlates/thresholds suggestive of protection against invasive GBS disease. This will then be followed by phase IV effectiveness studies to assess the burden of GBS vaccine preventable disease, including the effect on all-cause neonatal infections, neonatal deaths and stillbirths.

Group B Streptococcus and the risk of perinatal morbidity and mortality following term labor

Streptococcus agalactiae (group B Streptococcus) colonizes the genital tract of approximately 20% of pregnant women. In the absence of intervention, approximately 1% of infants born to colonized mothers exhibit a clinical infection. This has led to implementation of screening and intervention in the form of intrapartum antibiotic prophylaxis in many countries, including the United States. However, screening has not been introduced in a substantial minority of other countries because of the absence of supportive level 1 evidence, the very large number needed to treat to prevent 1 case, and concerns about antimicrobial resistance. Optimal screening would involve rapid turnaround (to facilitate intrapartum testing) and report antibiotic sensitivity, but no such method exists. There is significant scope for a personalized medicine approach, targeting intrapartum antibiotic prophylaxis to cases at greatest risk, but the pathogen and host factors determining the risk of invasive disease are incompletely understood. Epidemiologic data have indicated the potential of prelabor invasion of the uterus by group B Streptococcus, and metagenomic analysis revealed the presence of group B Streptococcus in the placenta in approximately 5% of pregnant women at term before onset of labor and membrane rupture. However, the determinants and consequences of prelabor invasion of the uterus by group B Streptococcus remain to be established. The vast majority (98%) of invasive neonatal disease is caused by 6 serotypes, and hexavalent vaccines against these serotypes have completed phase 2 trials. However, an obstacle to phase 3 studies is conducting an adequately powered trial to demonstrate clinical effectiveness given that early-onset disease affects approximately 1 in 1000 births in the absence of vaccination.

Group B Streptococcus in Pregnancy

To decrease risk of early-onset neonatal sepsis from group B streptococcus (GBS), pregnant patients should undergo screening between 36 0/7 and 37 6/7 weeks' gestation. Patients with a positive vaginal-rectal culture, GBS bacteriuria , or history of newborn with GBS disease should receive intrapartum antibiotic prophylaxis (IAP) with an agent targeting GBS. If GBS status is unknown at time of labor, IAP should be administered in cases of preterm birth, rupture of membranes for >18 hours, or intrapartum fever. The antibiotic of choice is intravenous penicillin; alternatives should be considered in cases of penicillin allergy depending on allergy severity.

Antibiotics in Labor and Delivery

Infections are common in obstetric care and often require specific antibiotics, depending on the infection site and prevailing organisms. Summaries of antibiotic recommendations and treatment algorithms are provided for the following conditions: routine labor, group B streptococcus prophylaxis, preterm prelabor rupture of membranes, operative vaginal delivery, cesarean delivery, obstetric anal sphincter lacerations, chorioamnionitis, postpartum endometritis, infections of the urinary tract, and bacterial endocarditis prophylaxis.

Maternal Origins of Neonatal Infections: What Do Obstetrician-Gynecologist Should/Could Do?

Neonatal infections are responsible for 20% of neonatal deaths yearly. In this review, we focused on the origins of the commoner neonatal infections, and we define the role of obstetricians. Regarding group B Streptococcus, a key measure for the prevention of neonatal infection is the vaginal-rectal culture screening at term pregnancy. Intravenous penicillin is the first-line prophylaxis at the start of labor, with intravenous ampicillin as an alternative. First-generation cephalosporins or clindamycin are recommended in case of penicillin allergy. Concerning urinary tract infections (UTIs), guidelines recommend complete urinalysis and urine culture in the first trimester of pregnancy for the screening of asymptomatic bacteriuria. For lower UTIs, guidelines recommend nitrofurantoin as first-choice antibiotic. Amoxicillin or cefalexin are second-line antibiotics. For upper UTIs, guidelines recommend cephalexin per os as first line. Candida spp. colonization affects 20% of pregnant women; however, congenital fetal candidosis and Candida amnionitis are rare. First-line treatment in case of symptomatic vaginitis during pregnancy or asymptomatic colonization during the third trimester is vaginal clotrimazole. Fluconazole is not approved in pregnancy, especially during the first trimester. Genital mycoplasmas colonization during pregnancy is usually asymptomatic and associated with bacterial vaginosis. Colonization is related to neonatal respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), pneumonia, chorioamnionitis, and sepsis. Macrolides are the first-line treatment along with lactobacillus supplementation. In cases of preterm premature rupture of membranes or preterm labor, ceftriaxone, clarithromycin, and metronidazole are required to prevent intra-amniotic infection. Intra-amniotic infection affects 1 to 5% of deliveries at term and one-third of preterm ones and is associated with perinatal death, early-onset neonatal sepsis, RDS, BPD, pneumonia, meningitis, and prematurity-related diseases. Guidelines recommend a combination of ampicillin and gentamicin, and in case of caesarean section, an additional dose of clindamycin or metronidazole is required. In conclusion, obstetricians should be aware that the treatment of maternal infection during pregnancy can prevent potentially lethal infections in the newborn. KEY POINTS: · Part of neonatal infections starts from maternal infections that must be treated during pregnancy.. · Streptococcus group B and asymptomatic bacteriuria should be investigated in pregnancy and treated.. · Mycoplasma and ureaplasma vaginal colonization during pregnancy is related to negative neonatal outcomes..

Maternal Group B Streptococcal Rectovaginal Colonization after Intrapartum Antibiotic Prophylaxis

Maternal rectovaginal colonization with Group B Streptococcus (GBS) during labor is a prerequisite for neonatal early-onset GBS disease. Intrapartum antibiotic prophylaxis (IAP) has been proven to prevent GBS perinatal infection, while there are few studies on the evaluation of the effectiveness of different antibiotic prophylaxis regimens. This study aimed to assess the maternal rectovaginal GBS colonization status after IAP, antimicrobial susceptibility and maternal and neonatal outcomes among women administered different antibiotic prophylaxis regimens. A prospective study was conducted between June 2018 and June 2022. GBS carriers identified at 35-37 weeks of gestation were provided IAP (penicillin, cefazolin or clindamycin) at delivery based on the local protocol for GBS prevention. Rectovaginal samples were obtained from participants again after delivery. Antimicrobial susceptibility testing in GBS isolates was performed using the broth microdilution method. A total of 295 cases were included in this study. In the postpartum re-examination for GBS, the overall negative rectovaginal culture rate was 90.8% (268/295). Women who received cefazolin prophylaxis had the highest negative culture rate (95.2%, 197/207), which was followed by those who received penicillin (80.7%, 67/83) and clindamycin (80.0%, 4/5) (p = 0.001). All GBS isolates achieved sensitivity to penicillin and cefazolin, whereas resistance to clindamycin was shown in 21.4% of the strains. There were no significant differences in maternal and neonatal outcomes among the IAP groups. The use of IAP is highly effective in reducing the maternal rectovaginal GBS colonization. Cefazolin may offer equivalent efficacy and safety compared to standard penicillin prophylaxis.

An Application of Real-Time PCR and CDC Protocol May Significantly Reduce the Incidence of Streptococcus agalactiae Infections among Neonates

Streptococcus agalactiae is an important human opportunistic pathogen, especially infectious for pregnant women and neonates. This pathogen belongs to beta hemolytic Streptococcus spp. representatives and accounts for a significant part of early infections in newborns, including serious life-threatening infections. This research investigated the usefulness of Centers for Disease Control and Prevention (CDC) protocol for S. agalactiae DNA detection in 250 samples of recto-vaginal swabs collected from pregnant women (at 35-37 weeks of gestation) and pre-cultured overnight in liquid medium. With an application of the CDC protocol-based real-time PCR, the cfb gene was detected in 68 (27.2%) samples compared to 41 (16.4%) for the standard culture-based methodology. The applied molecular method presented high sensitivity (100.0%) and specificity (87.1%). Therefore, it allowed for more precise detection of S. agalactiae bacteria, compared to the reference diagnostic method, culture on solid media with the following strain identification. The increased sensitivity of GBS detection may result in a reduced number of infections in newborns and leads to more targeted antimicrobial prophylaxis therapy of GBS infections in pregnant women. In addition, the use of the molecular method allows for a significant reduction in the time needed to obtain a result for GBS detection, and interpretation of the results is relatively simple. Therefore, it enables a faster intervention in case of a necessity of an antibiotic therapy introduction in pregnant women whose GBS status is unknown at the time of delivery.

Perinatal excellence to reduce injury in preterm birth (PERIPrem) through quality improvement

Perinatal Excellence to Reduce Injury in Premature Birth (PERIPrem) is an 11-element perinatal care bundle designed to improve outcomes for preterm babies, in line with the National Health Service (NHS) Long Term plan. Designed in collaboration with 12 NHS Trusts (secondary care hospitals), South West and West of England Academic Health Science Networks, South West Neonatal Operational Delivery Network, parent partners and clinical experts, implementation was via bespoke quality improvement (QI) methodology. Before project initiation, there was regional variation in uptake of elements, evidenced by baseline audit. Optimisation of the preterm infant is complex; eligibility for treatments is dependent on gestation and local policies. Preterm infants experience variability in care dependent on the place of birth, and there remains an implementation gap for several effective, evidence-based treatments.

The PERIPrem ambition is to reduce severe brain injury and death caused by prematurity by at least 50% through the delivery of a perinatal care bundle. The PERIPrem approach resulted in improved element implementation by 26% (from 3% to 29%) between 2019 and 2021, with dyads significantly more likely to receive the full bundle in 2021 compared with 2019 (probability=0.96 (95% CI 0.87 to 0.99), p<0.001). When examining the impact on psychological safety and team-working of PERIPrem, linear mixed models indicated an improvement in team function (p=0.021), situation monitoring (p=0.029) and communication within teams (p=0.002). Central to success was the development of a committed multiorganisational collaborative that continues to drive perinatal improvement using a common language and streamlining processes. In addition to saving the lives of the most vulnerable babies, PERIPrem aims to improve the chances of disability-free lives and is successfully nurturing high-functioning perinatal teams with enhanced QI skills.

Prevalence of Group B Streptococcus Recto-Vaginal Colonization, Vertical Transmission, and Antibiotic Susceptibility Among Pregnant Women in Ethiopia: A Systematic Review and Meta-Analysis

Background

Maternal Group B Streptococcus (GBS) recto-vaginal colonization is the most common route for early onset neonatal GBS diseases. A good understanding of the rate of maternal GBS colonization, vertical transmission rate, and antibiotic susceptibility profiles is needed to formulate a broad protection mechanism, like vaccine preparation. For that reason, this meta-analysis aimed at determining the pooled prevalence of GBS recto-vaginal colonization, vertical transmission rate, and antibiotic susceptibility profiles in Ethiopia.

Methods

Both published and unpublished studies were searched from MEDLINE/PubMed, CINAHL (EBSCO), Embase, Cochrane Library, SCOPUS, Web of Sciences databases, and Google Scholar. Independent selection was then carried out by the authors based on the eligibility criteria and data extraction using Microsoft excel. The authors then used STATA version 14.1 software for further cleaning and analysis. The review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines. Using the random-effect model, the prevalence with a 95% confidence interval (CI) and forest plot were used to present the findings. Besides, the studies' heterogeneity was assessed using Cochrane chi-square (I2) statistics, while Egger intercept was used to assess publication bias.

Results

This review included nineteen studies. The pooled prevalence of recto-vaginal colonization was 15% (95% CI: 11, 19), while the prevalence of vertical transmission was 51% (95% CI: 45, 58) and highest-level susceptibility to vancomycin was 99% (95% CI: 98, 100). However, the GBS susceptibility to tetracycline was 23% (95% CI: 9, 36).

Conclusions

Nearly one out of seven pregnant women in Ethiopia had recto-vaginal colonization of GBS. As a result, half of the pregnancies end with vertical transmission of GBS. Hence, the review emphasizes that policy and programs should consider planning and implementing prophylactic programs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021287540.

Improving Intrapartum Group B Streptococcus Prophylaxis in Patients with a Reported Penicillin or Cephalosporin Allergy: A Quality Improvement Project

OBJECTIVE

To evaluate the impact of a standardized allergy-guided approach to Group B Streptococcus (GBS) prophylaxis in pregnant women with reported penicillin or cephalosporin allergy.

METHODS

This interrupted time-series analysis included obstetric patients requiring GBS prophylaxis who reported penicillin or cephalosporin allergies. Patients were divided into baseline (April 1, 2019 to July 21, 2020) and intervention (July 22, 2020 to July 31, 2021) groups. The primary outcome was prophylaxis appropriateness, based on antibiotic type, nature of reaction, and cross-reactivity risk. Secondary outcomes included type of prophylaxis received and antibiotic-related adverse events.

RESULTS

The study included 88 patients in the baseline period and 52 patients in the intervention period. Appropriate prophylaxis increased from 47% (41/88) to 85% (44/52), with the segmented regression model confirming a statistically significant increase over time (incidence rate ratio 1.57; 95% CI 1.02-2.43, P = 0.04, slope coefficient 1.06/month; 95% CI 1.01-1.10, P = 0.01). Penicillin and cefazolin use increased from 61% (54/88) to 87% (45/52) in the intervention period (P = 0.002), and no hypersensitivity reactions occurred during this period.

CONCLUSIONS

Implementation of standardized allergy-guided prophylaxis safely improved appropriate β-lactam antibiotic use in obstetric patients requiring GBS prophylaxis who reported penicillin and cephalosporin allergies.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

Rapid intrapartum test for maternal group B streptococcal colonisation and its effect on antibiotic use in labouring women with risk factors for early-onset neonatal infection (GBS2): cluster randomised trial with nested test accuracy study

BACKGROUND

Mother-to-baby transmission of group B Streptococcus (GBS) is the main cause of early-onset infection. We evaluated whether, in women with clinical risk factors for early neonatal infection, the use of point-of-care rapid intrapartum test to detect maternal GBS colonisation reduces maternal antibiotic exposure compared with usual care, where antibiotics are administered due to those risk factors. We assessed the accuracy of the rapid test in diagnosing maternal GBS colonisation, against the reference standard of selective enrichment culture.

METHODS

We undertook a parallel-group cluster randomised trial, with nested test accuracy study and microbiological sub-study. UK maternity units were randomised to a strategy of rapid test (GeneXpert GBS system, Cepheid) or usual care. Within units assigned to rapid testing, vaginal-rectal swabs were taken from women with risk factors for vertical GBS transmission in established term labour. The trial primary outcome was the proportion of women receiving intrapartum antibiotics to prevent neonatal early-onset GBS infection. The accuracy of the rapid test was compared against the standard of selective enrichment culture in diagnosing maternal GBS colonisation. Antibiotic resistance profiles were determined in paired maternal and infant samples.

RESULTS

Twenty-two maternity units were randomised and 20 were recruited. A total of 722 mothers (749 babies) participated in rapid test units; 906 mothers (951 babies) were in usual care units. There was no evidence of a difference in the rates of intrapartum antibiotic prophylaxis (relative risk 1.16, 95% CI 0.83 to 1.64) between the rapid test (41%, 297/716) and usual care (36%, 328/906) units. No serious adverse events were reported. The sensitivity and specificity measures of the rapid test were 86% (95% CI 81 to 91%) and 89% (95% CI 85 to 92%), respectively. Babies born to mothers who carried antibiotic-resistant Escherichia coli were more likely to be colonised with antibiotic-resistant strains than those born to mothers with antibiotic-susceptible E. coli.

CONCLUSION

The use of intrapartum rapid test to diagnose maternal GBS colonisation did not reduce the rates of antibiotics administered for preventing neonatal early-onset GBS infection than usual care, although with considerable uncertainty. The accuracy of the rapid test is within acceptable limits.

TRIAL REGISTRATION

ISRCTN74746075 . Prospectively registered on 16 April 2015.

Listeriosis in infants: Prospective surveillance studies in Canada and Switzerland

Objectives

International data on listeriosis during infancy from large populations are essential to guide evidence-based empiric antibiotic guidelines for sepsis in infancy. We aimed to determine the incidence, clinical manifestations, and outcome of listeriosis in infants <6 months of age in Canada and Switzerland.

Methods

Prospective, active surveillance of listeriosis in infants <6 months of age was conducted through the Canadian Paediatric Surveillance Program (May 2015 to April 2017) and the Swiss Paediatric Surveillance Unit (April 2017 to March 2018). Confirmed and probable cases were included.

Results

In Canada, eight sporadic listeriosis cases were reported (incidence, 1.1/100,000 live births/year). In Switzerland, four cases were reported (incidence, 4.5/100,000 live births/year) of which three were part of a confirmed outbreak with an unclear source. In the two countries, eight of the 12 cases (66.6%) presented as early-onset disease (within the first 7 days of life) and none presented after 28 days life.

Conclusions

Neonatal listeriosis is rare. Infants presenting with sepsis, especially after 4 weeks of life, may not routinely require empiric antibiotic coverage for listeriosis. Outbreak-related cases still occur. Continued surveillance is important.

Intrapartum group B Streptococcal prophylaxis and childhood weight gain

OBJECTIVE

To determine the difference in rate of weight gain from birth to 5 years based on exposure to maternal group B streptococcal (GBS) intrapartum antibiotic prophylaxis (IAP).

DESIGN

Retrospective cohort study of 13 804 infants.

SETTING

Two perinatal centres and a primary paediatric care network in Philadelphia.

PARTICIPANTS

Term infants born 2007-2012, followed longitudinally from birth to 5 years of age.

EXPOSURES

GBS IAP defined as penicillin, ampicillin, cefazolin, clindamycin or vancomycin administered ≥4 hours prior to delivery to the mother. Reference infants were defined as born to mothers without (vaginal delivery) or with other (caesarean delivery) intrapartum antibiotic exposure.

OUTCOMES

Difference in rate of weight change from birth to 5 years was assessed using longitudinal rate regression. Analysis was a priori stratified by delivery mode and adjusted for relevant covariates.

RESULTS

GBS IAP was administered to mothers of 2444/13 804 (17.7%) children. GBS IAP-exposed children had a significantly elevated rate of weight gain in the first 5 years among vaginally-born (adjusted rate difference 1.44% (95% CI 0.3% to 2.6%)) and caesarean-born (3.52% (95% CI 1.9% to 5.2%)) children. At 5 years, the rate differences equated to an additional 0.24 kg among vaginally-born children and 0.60 kg among caesarean-born children.

CONCLUSION

GBS-specific IAP was associated with a modest increase in rate of early childhood weight gain. GBS IAP is an effective intervention to prevent perinatal GBS disease-associated morbidity and mortality. However, these findings highlight the need to better understand effects of intrapartum antibiotic exposure on childhood growth and support efforts to develop alternate prevention strategies.

Analysis of Susceptibility to the Antimicrobial and Anti-Biofilm Activity of Human Milk Lactoferrin in Clinical Strains of Streptococcus agalactiae With Diverse Capsular and Sequence Types

Group B Streptococcus (GBS) is one of the leading infection-related causes of adverse maternal and neonatal outcomes. This includes chorioamnionitis, which leads to preterm ruptures of membranes and can ultimately result in preterm or stillbirth. Infection can also lead to maternal and neonatal sepsis that may contribute to mortality. Currently, treatment for GBS infection include a bolus of intrapartum antibiotic prophylaxis to mothers testing positive for GBS colonization during late pregnancy. Lactoferrin is an antimicrobial peptide expressed in human breast milk, mucosal epithelia, and secondary granules of neutrophils. We previously demonstrated that lactoferrin possesses antimicrobial and antibiofilm properties against several strains of GBS. This is largely due to the ability of lactoferrin to bind and sequester iron. We expanded upon that study by assessing the effects of purified human breast milk lactoferrin against a panel of phenotypically and genetically diverse isolates of GBS. Of the 25 GBS isolates screened, lactoferrin reduced bacterial growth in 14 and biofilm formation in 21 strains. Stratifying the data, we observed that colonizing strains were more susceptible to the growth inhibition activity of lactoferrin than invasive isolates at lactoferrin concentrations between 250-750 µg/mL. Treatment with 750 µg/mL of lactoferrin resulted in differences in bacterial growth and biofilm formation between discrete sequence types. Differences in bacterial growth were also observed between capsular serotypes 1a and III. Maternally isolated strains were more susceptible to lactoferrin with respect to bacterial growth, but not biofilm formation, compared to neonatal sepsis isolates. Finally, high biofilm forming GBS strains were more impacted by lactoferrin across all isolates tested. Taken together, this study demonstrates that lactoferrin possesses antimicrobial and antibiofilm properties against a wide range of GBS isolates, with maternally isolated colonizing strains being the most susceptible.

Updates in prevention policies of early-onset group B streptococcal infection in newborns

Invasive disease owing to group B Streptococcus (GBS) is a major cause of illness and death among newborns. Maternal GBS colonization of gastrointestinal tract and/or vagina is the primary risk factor for neonatal GBS early-onset disease (EOD). In Europe and America, there are marked declines in neonatal GBS-EOD through widespread implementation of guidelines for maternal GBS screening and subsequent intrapartum antibiotic prophylaxis (IAP). The key measures necessary for prevention of GBS-EOD include correct specimen collection and processing, nucleic acid amplification testing (NAAT) for GBS identification, regimens for mothers with premature rupture of membranes (PROM), preterm labor or penicillin allergy, and coordination between obstetrics and pediatrics. Antibiotic prophylaxis has some disadvantages, so researchers should develop other preventive measures. Maternal vaccines to prevent perinatal GBS infection are currently under development. However, as large, population-based sampling studies are rarely conducted, the colonization rate and the disease burden of GBS in perinatal period are poorly understood in developing countries. The harm of GBS to newborns has been recognized in recent years in mainland China, but authorized prevention measures are still lacking. In order to enhance the understanding of GBS-EOD prevention, the most recent guidelines updates by the American College of Obstetricians and Gynecologists (ACOG) and American Academy of Pediatrics (AAP) in 2019-2020 are summarized in this article.

Intrapartum antibiotic prophylaxis for women who are screened positive for group B streptococcal colonisation: Clinical compliance with the guideline

BACKGROUND

In high income countries, ~30% of pregnant women are provided with intrapartum antibiotic prophylaxis (IAP) for early-onset group B streptococcal infection (EOGBSI). The infection rate is low, 0.2/1000 livebirths in our jurisdiction, and others. We hypothesised factors, other than IAP alone, were reasons for the low rate of EOGBSI.

AIMS

Compliance with our local guideline, referred to here as 'the guideline'.

METHOD

Compliance was defined as an initial dose of benzylpenicillin IAP followed by four-hourly doses until birth. The study population was drawn from 4098 women who had 4100 pregnancies resulting in 4200 babies in an Australian birth setting from 1/1/2016 to 31/12/2016. Most, 93%, were eligible for universal GBS screening, 67% were reported as screened and 90% of these had a result documented; 23% were positive for GBS. A random sample (n = 223) was taken for further analysis.

RESULTS

The adjusted odds of receiving benzylpenicillin IAP in accord with the guideline were three times higher among primiparous compared to multiparous women (P < 0.001, odds ratio (OR) = 3.4, 95% CI 1.7-6.7) and three times higher among women experiencing induction of labour compared to women who commenced labour spontaneously (P < 0.001, OR = 3.4, 95% CI 1.8-6.3). Of the 223 women, 188 received IAP: 176 received benzylpenicillin IAP, 31% (or 24% of the total sample) received this intervention in accord with the guideline, 24% received benzylpenicillin ≥4 h before birth but not in accord with the guideline and 44% received benzylpenicillin <4 h before birth.

CONCLUSION

We conclude that sub-optimal compliance was largely a consequence of an unrealistic guideline.

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.

Birth signalling hormones and the developmental consequences of caesarean delivery

Rates of delivery by caesarean section (CS) are increasing around the globe and, although several epidemiological associations have already been observed between CS and health outcomes in later life, more are sure to be discovered as this practice continues to gain popularity. The components of vaginal delivery that protect offspring from the negative consequences of CS delivery in later life are currently unknown, although much attention to date has focused on differences in microbial colonisation. Here, we present the case that differing hormonal experiences at birth may also contribute to the neurodevelopmental consequences of CS delivery. Levels of each of the 'birth signalling hormones' (oxytocin, arginine vasopressin, epinephrine, norepinephrine and the glucocorticoids) are lower following CS compared to vaginal delivery, and there is substantial evidence for each that manipulations in early life results in long-term neurodevelopmental consequences. We draw from the research traditions of neuroendocrinology and developmental psychobiology to suggest that the perinatal period is a sensitive period, during which hormones achieve organisational effects. Furthermore, there is much to be learned from research on developmental programming by early-life stress that may inform research on CS, as a result of shared neuroendocrine mechanisms at work. We compare and contrast the effects of early-life stress with those of CS delivery and propose new avenues of research based on the links between the two bodies of literature. The research conducted to date suggests that the differences in hormone signalling seen in CS neonates may produce long-term neurodevelopmental consequences.

Update on Prenatal Laboratory Screening: Joint Commission Required Elements

The Centers for Disease Control and Prevention, the American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics recommend routine screening for pregnant women for evidence of infection with human immunodeficiency virus, hepatitis B and syphilis, and vaginal-rectal colonization with group B Streptococcus For each of these pathogens, there are important opportunities to provide maternal treatment, prevent vertical transmission of the pathogen during the prenatal or intrapartum periods, and/or administer neonatal treatment immediately after birth. Such prevention and/or treatment measures are critical to limiting maternal and neonatal morbidity; however, this is dependent on recognition of maternal disease status. A significant number of women in the United States receive either inadequate prenatal care or inadequate screening for these pathogens. The time of admission to labor and delivery units represents an important opportunity to detect at-risk pregnant women and infants. To optimize both maternal and neonatal health, the Joint Commission issued new guidance effective July 1, 2018, mandating documentation of maternal disease status for these pathogens in the maternal medical record and documentation of positive results in the newborn medical record. Immediate peripartum testing for women with inadequate screening is also required. These measures should allow for timely interventions to improve maternal health and ideally to prevent perinatal disease transmission to the newborn.

To screen or not to screen women for Group B Streptococcus (Streptococcus agalactiae) to prevent early onset sepsis in newborns: recent advances in the unresolved debate

Streptococcus agalactiae, also known as Group B streptococcus (GBS) is the commonest cause of early onset sepsis in newborns in developed high-income countries. Intrapartum antimicrobial (antibiotic) prophylaxis (IAP) is recognized to be highly effective in preventing early onset Group B sepsis (EOGBS) in newborns. The key controversy is about the strategy that should be used to identify mothers who should receive IAP. There are two strategies that are followed in developed countries: screening-based or risk-factor-based identification of women requiring IAP. The debate regarding which of the two approaches is better has intensified in the recent years with concerns about antimicrobial resistance, effect on newborn’s microbiome and other adverse effects. In this review, we have discussed some of the key research papers published in the period 2015–2019 that have addressed the relative merits and disadvantages of screening versus risk-factor-based identification of women requiring IAP. Although screening-based IAP appears to be more efficacious than risk-based IAP, IAP-based prevention has several limitations including ineffectiveness in prevention of late-onset GBS infection in babies, premature and still births, impact of IAP on neonatal microbiota, emergence of antimicrobial resistance and difficulties in implementing IAP-based strategies in middle and low income countries. Alternative strategies, principally maternal immunization against GBS would circumvent use of IAP. However, no licensed vaccines are currently available for use.

Cost Effectiveness of Latest Recommendations for Group B Streptococci Screening in the United States

OBJECTIVE

To evaluate whether group B streptococci (GBS) screening using the 2010 guideline (screening at 35 0/7-37 6/7 weeks of gestation) compared with the 2019 guideline (screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results 5 weeks later) was more cost effective.

METHODS

We constructed a decision-analysis model to compare the outcome of GBS early-onset disease in a hypothetical cohort of 3,614,049 women at 35 0/7 weeks of gestation or greater (the number of live births in 2017 excluding births based on population frequency from 23 to 34 weeks of gestation, women with GBS bacteriuria during the current pregnancy, and those with a history of a previous neonate with GBS disease). We took both a health care and societal perspective and all costs were expressed in 2017 U.S. dollars. Effectiveness was based on neonatal quality-adjusted life years (QALYs) gained. An incremental cost-effectiveness ratio was estimated with a willingness to pay threshold set at $100,000/QALY. All model inputs were derived from the literature. One-way probability and cost sensitivity analysis were performed to investigate model assumptions.

RESULTS

Screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results if 5 weeks passed from culture to delivery resulted in a 6% increase in neonatal QALYs gained (2,162 vs 2,037), 12% fewer cases of neonatal death (30 vs 34), and a 10% estimated reduction in total societal health care expenditures related to GBS early-onset disease ($639 million vs $707 million) when compared with the 2010 strategy of only screening at 35 0/7-37 6/7 weeks of gestation. The 2019 approach was cost effective, with an incremental cost-effectiveness ratio of $43,205 per neonatal QALY gained.

CONCLUSION

Screening at 36 0/7-37 6/7 weeks of gestation with a 5-week re-screening for women with GBS-negative results is more cost effective than past strategies used in the United States.

Analysis of Faecal Zonulin and Calprotectin Concentrations in Healthy Children During the First Two Years of Life. An Observational Prospective Cohort Study

Factors affecting the intestinal-barrier permeability of newborns, such as body mass index (BMI), nutrition and antibiotics, are assumed to affect intestinal-barrier permeability in the first two years of life. This study assessed 100 healthy, full-term newborns to 24 months old. Faecal zonulin/calprotectin concentrations were measured at 1, 6, 12, 24 months as gut-permeability markers. Zonulin concentrations increased between 1 and 12 months (medians: 114.41, 223.7 ng/mL; respectively), whereas calprotectin concentrations decreased between one and six months (medians: 149. 29, 109.28 µg/mL); both then stabilized (24 months: 256.9 ng/mL zonulin; 59.5 µg/mL calprotectin). In individual children, high levels at one month gave high levels at older ages (correlations: calprotectin: between 1 and 6 or 12 months: correlation coefficient (R) = 0.33, statistical significance (p) = 0.0095; R = 0.28, p = 0.032; zonulin: between 1 and 24 months: R = 0.32; p = 0.022, respectively). Parameters which gave marker increases: antibiotics during pregnancy (calprotectin; six months: by 80%, p = 0.038; 12 months: by 48%, p = 0.028); vaginal birth (calprotectin: 6 months: by 140%, p = 0.005); and > 5.7 pregnancy-BMI increase (zonulin: 12 months: by 74%, p = 0.049). Conclusions: “Closure of the intestines” is spread over time and begins between the sixth and twelfth month of life. Antibiotic therapy, BMI increase > 5.7 during pregnancy and vaginal birth are associated with increased intestinal permeability during the first two years of life. Stool zonulin and calprotectin concentrations were much higher compared with previous measurements at older ages; clinical interpretation and validation are needed (no health associations found).

A Retrospective Review of Neonatal Sepsis among GBS-Colonized Women Undergoing Planned Cesarean Section after Labor Onset or Rupture of Membranes

Background

Sepsis is a leading cause of mortality and morbidity in neonates, with group B streptococcus (GBS) remaining the most frequent pathogen isolated from term infants. Surveillance data showed that the majority of cases of early-onset GBS disease were neonates born to women who either received no or suboptimal intrapartum antibiotic prophylaxis with a notable portion of those women having a missed opportunity to receive ≥4 hours of chemoprophylaxis. Women planning delivery by cesarean section who present in labor or rupture of membranes prior to their scheduled surgery are unlikely to receive optimal GBS chemoprophylaxis and thus their neonates are at risk of having sepsis. Materials and Methods. A retrospective cohort study of women-infant dyads was extracted from the Consortium on Safe Labor dataset. Women who had an unlabored cesarean section at ≥37 + 0 week gestation were selected and divided into four groups based on GBS status and timing of cesarean section with respect to onset of labor or rupture of membranes. The rate of neonatal sepsis and the patterns of intrapartum antibiotic chemoprophylaxis were determined.

Results

The sepsis rate (4.5%) among neonates of GBS-colonized women having their unlabored cesarean section after onset of labor or rupture of membranes was significantly higher than that in any other group in this study. In this group, 9.4% of women received chemoprophylaxis for ≥4 hours, while 31% had a missed opportunity to receive ≥4 hours of chemoprophylaxis.

Conclusion

This study suggests that neonates of GBS-colonized women having a planned cesarean section after onset of labor or rupture of membranes are at increased risk of having a sepsis diagnosis. This finding suggest the need for additional studies to assess the risk of sepsis among neonates of women in this group.

Time Has Come for Routine Penicillin Allergy Testing in Obstetrics

Objective  This study evaluates penicillin allergy during pregnancy to estimate the proportion that could benefit from penicillin allergy testing. Study Design  Retrospective cohort study of women with penicillin allergy that delivered from January 1, 2018 to December 31, 2018. Results  Among 6,321 deliveries, 446 (7%) were identified with penicillin allergy. Nine percent (41/446) had no documentation of allergy severity. Allergies associated with intolerance, low, moderate, or high risk of anaphylaxis were reported in 6% (25/446), 40% (177/446), 32% (142/446), and 14% (61/446), respectively. Nearly 74% (330/446) received an antibiotic either antepartum, at delivery, or within 6 weeks of postpartum. The majority of women, 81% (360/446) (i.e., undocumented reactions, low, or moderate risk of anaphylaxis) would have been eligible for penicillin allergy testing. Greater appropriate utilization of antibiotics occurred in women with a high 80% (39/49) or moderate risk of anaphylaxis 70% (79/112) versus low risk of anaphylaxis 55% (64/117), history of intolerance 40% (8/20), or undocumented reaction 19% (6/32), p  ≤ 0.01. Conclusion  Most women who report a penicillin allergy during pregnancy would be candidates for penicillin allergy testing. With the high rate of antibiotic interventions in pregnant women who report a penicillin allergy, consideration should be given for penicillin allergy assessment.

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.

Community-acquired serious bacterial infections in the first 90 days of life: a revisit in the era of multi-drug-resistant organisms

BACKGROUND

Infants in the first 90 days of life are more prone to develop serious bacterial infections (SBIs). Multi-drug-resistant organisms (MDROs) are emerging as important pathogens causing SBIs. We reviewed the epidemiology of SBIs in infants 0-90 days old and compared the clinical features, laboratory values and final outcome for SBIs due to MDROs vs. non-MDROs.

METHODS

Episodes of culture-proven SBIs (bacteremia, urinary tract infections, or meningitis) with age at onset of 0-90 days during a 7-year period were retrospectively reviewed. Health care-associated infections were excluded. We collected demographics, clinical features, and laboratory and microbiology data. We compared clinical characteristics, laboratory data, microbiologic results and final outcome for SBIs due to MDROs vs. non-MDROs.

RESULTS

Ninety-four episodes (88 patients) including bacteremia (42.6%), urinary tract infections (54.3%) and meningitis (3.1%) were caused by Gram-negative bacteria (67%), and Gram-positive bacteria (33%). Escherichia coli, Klebsiella pneumoniae and GBS were the most common causes. MDROs caused SBIs in 39 patients (44.3%). SBIs due to MDROs were associated with more delay in providing targeted antimicrobial therapy compared to non-MDROs (74.4% vs. 0%, P ≤ 0.001), but no difference in case-fatality rate (12.8% vs. 12.2%, P = 1.0). Clinical features or basic laboratory values were not statistically different between the two groups.

CONCLUSIONS

The bacteriology of SBIs in the first 90 days of life is changing to include more MDROs, which causes more delay in providing targeted antimicrobial therapy. Awareness of the local epidemiology is crucial to ensure appropriate antibiotics are provided in a timely manner.

Management of Infants at Risk for Group B Streptococcal Disease

Group B streptococcal (GBS) infection remains the most common cause of neonatal early-onset sepsis and a significant cause of late-onset sepsis among young infants. Administration of intrapartum antibiotic prophylaxis is the only currently available effective strategy for the prevention of perinatal GBS early-onset disease, and there is no effective approach for the prevention of late-onset disease. The American Academy of Pediatrics joins with the American College of Obstetricians and Gynecologists to reaffirm the use of universal antenatal microbiologic-based testing for the detection of maternal GBS colonization to facilitate appropriate administration of intrapartum antibiotic prophylaxis. The purpose of this clinical report is to provide neonatal clinicians with updated information regarding the epidemiology of GBS disease as well current recommendations for the evaluation of newborn infants at risk for GBS disease and for treatment of those with confirmed GBS infection. This clinical report is endorsed by the American College of Obstetricians and Gynecologists (ACOG), July 2019, and should be construed as ACOG clinical guidance.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 782

Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."

The Influence of Maternal-Foetal Parameters on Concentrations of Zonulin and Calprotectin in the Blood and Stool of Healthy Newborns during the First Seven Days of Life. An Observational Prospective Cohort Study

Background: It can be hypothetically assumed that maternal and perinatal factors influence the intestinal barrier. Methods: The study was conducted with 100 healthy, full-term newborns breastfed in the first week of life, with similar analyses for their mothers. Zonulin and calprotectin levels were used as intestinal permeability markers. Results: The median (range) zonulin concentrations (ng/mL) were in mothers: serum, 21.39 (6.39–57.54); stool, 82.23 (42.52–225.74); and newborns: serum cord blood, 11.14 (5.82–52.34); meconium, 54.15 (1.36–700.65); and stool at age seven days, 114.41 (29.38–593.72). Calprotectin median (range) concentrations (µg/mL) in mothers were: stool, 74.79 (3.89–211.77); and newborns: meconium, 154.76 (6.93–8884.11); and stool at age seven days 139.12 (11.89–627.35). The use of antibiotics during pregnancy resulted in higher zonulin concentrations in umbilical-cord serum and calprotectin concentrations in newborn stool at seven days, while antibiotic therapy during labour resulted in higher zonulin concentrations in the stool of newborns at seven days. Zonulin concentrations in the stool of newborns (at seven days) who were born via caesarean section were higher compared to with vaginal birth. With further analyses, caesarean section was found to have a greater effect on zonulin concentrations than prophylactic administration of antibiotics in the perinatal period. Pregnancy mass gain >18 kg was associated with higher calprotectin concentrations in maternal stool. Body Mass Index (BMI) increase >5.7 during pregnancy was associated with decreased zonulin concentrations in maternal stool and increased calprotectin concentrations in stool of mothers and newborns at seven days. There was also a negative correlation between higher BMI increase in pregnancy and maternal zonulin stool concentrations and a positive correlation between BMI increase in pregnancy and maternal calprotectin stool concentrations. Conclusion: Maternal-foetal factors such as caesarean section, antibiotic therapy during pregnancy, as well as change in mother’s BMI during pregnancy may increase intestinal permeability in newborns. Changes in body mass during pregnancy can also affect intestinal permeability in mothers. However, health consequences associated with increased intestinal permeability during the first days of life are unknown. Additionally, before the zonulin and calprotectin tests can be adopted as universal diagnostic applications to assess increased intestinal permeability, validation of these tests is necessary.

Group B streptococcal screening, intrapartum antibiotic prophylaxis, and neonatal early-onset infection rates in an Australian local health district: 2006-2016

BACKGROUND

Intrapartum antibiotic prophylaxis (IAP) to reduce the likelihood of neonatal early-onset group B streptococcal infection (EOGBS) has coincided with major reductions in incidence. While the decline has been largely ascribed to IAP following either universal screening or a risk-based approach to identify mothers whose babies may most benefit from IAP, there is lack of high quality evidence to support this view.

AIMS

To describe management of maternal GBS colonisation in one local health district using universal screening and assess rates of EOGBS over time.

METHODS

A retrospective cohort study was undertaken to describe compliance with GBS management, to determine the incidence of EOGBS and association between rates and maternal screening. Linking routinely collected maternity and pathology data, we explored temporal trends using logistic regression and covariates for potential effect modifiers.

RESULTS

Our cohort included 62,281 women who had 92,055 pregnancies resulting in 93,584 live born babies. Screening occurred in 76% of pregnancies; 69% had a result recorded, 21.5% of those were positive for GBS. Prophylaxis was used by 79% of this group. Eighteen babies developed EOGBS, estimated incidence/1000 live births in 2006 and 2016 was 0.35 (95% CI, 0.07 to 0.63) and 0.1 (95% CI, 0 to 0.2) respectively. Seven of 10 term babies with EOGBS were born to mothers who screened negative. Data were unable to provide evidence of difference in rates of EOGBS between screened and unscreened pregnancies. We estimated the difference in EOGBS incidence from crude and weighted models to be 0 (95% CI, -0. 2 to 0.17) and -0.01 (95% CI, -0.13 to 0.10) /1000 live births respectively.

CONCLUSION

No change was detected in rates of EOGBS over time and no difference in EOGBS in babies of screened and unscreened populations. Screening and prophylaxis rates were modest. Limitations of universal screening suggest alternatives be considered.

Modelling the effect of the introduction of antenatal screening for group B Streptococcus (GBS) carriage in the UK

OBJECTIVES

To estimate the potential impact of the addition of culture-based screening for group B streptococcus (GBS) carriage in pregnancy to a risk-based prevention policy in the UK. We aimed to establish agreement within a multidisciplinary group of key stakeholders on the model input parameters.

DESIGN

Deterministic model using a consensus approach for the selection of input parameters.

SETTING AND PARTICIPANTS

A theoretical annual cohort of 711 999 live births in the UK (excluding births by elective caesarean section).

INTERVENTIONS

Culture-based screening for GBS at 35-37 weeks of pregnancy added to the recommended risk-based prevention policy in place on the date of modelling.

OUTCOME MEASURES

Outcomes assessed included use of intrapartum antibiotic prophylaxis (IAP), early onset GBS (EOGBS), EOGBS mortality, severe EOGBS-related morbidity and maternal penicillin anaphylaxis.

RESULTS

With no prophylaxis strategy, the model estimated that there would be 421 cases of culture positive EOGBS in a year (0.59/1000 live births). In the risk-based prophylaxis scenario, 30 666 women were estimated to receive IAP and 70 cases of EOGBS were prevented. Addition of screening resulted in a further 96 260 women receiving IAP and the prevention of an additional 52 to 57 cases of EOGBS. This resulted in the prevention of three EOGBS deaths and four cases of severe disability. With screening, an additional 1675 to 1854 women receive IAP to prevent one EOGBS case and 24 065 to 32 087 receive IAP to prevent one EOGBS death.

CONCLUSIONS

The evidence base available for a broad range of model input parameters was limited, leading to uncertainty in the estimates produced by the model. Where data was limited, the model input parameters were agreed with the multidisciplinary stakeholder group, the first time this has been done to our knowledge. The main impact of screening is likely to be on the large group of low-risk women where the clinical impact of EOGBS tends to be less severe. This model suggests that the reduction in mortality and severe disability due to EOGBS with antenatal GBS screening is likely to be very limited, with a high rate of overdetection and overuse of antibiotics.

Epidemiology of Invasive Early-Onset and Late-Onset Group B Streptococcal Disease in the United States, 2006 to 2015: Multistate Laboratory and Population-Based Surveillance

IMPORTANCE

Invasive disease owing to group B Streptococcus (GBS) remains an important cause of illness and death among infants younger than 90 days in the United States, despite declines in early-onset disease (EOD; with onset at 0-6 days of life) that are attributed to intrapartum antibiotic prophylaxis (IAP). Maternal vaccines to prevent infant GBS disease are currently under development.

OBJECTIVE

To describe incidence rates, case characteristics, antimicrobial resistance, and serotype distribution of EOD and late-onset disease (LOD; with onset at 7-89 days of life) in the United States from 2006 to 2015 to inform IAP guidelines and vaccine development.

DESIGN, SETTING, AND PARTICIPANTS

This study used active population-based and laboratory-based surveillance for invasive GBS disease conducted through Active Bacterial Core surveillance in selected counties of 10 states across the United States. Residents of Active Bacterial Core surveillance areas who were younger than 90 days and had invasive GBS disease in 2006 to 2015 were included. Data were analyzed from December 2017 to April 2018.

EXPOSURES

Group B Streptococcus isolated from a normally sterile site.

MAIN OUTCOMES AND MEASURES

Early-onset disease and LOD incidence rates and associated GBS serotypes and antimicrobial resistance.

RESULTS

The Active Bacterial Core surveillance program identified 1277 cases of EOD and 1387 cases of LOD. From 2006 to 2015, EOD incidence declined significantly from 0.37 to 0.23 per 1000 live births (P < .001), and LOD rates remained stable (mean, 0.31 per 1000 live births). Among the mothers of 1277 infants with EOD, 617 (48.3%) had no indications for IAP and did not receive it, and 278 (21.8%) failed to receive IAP despite having indications. Serotype data were available for 1743 of 1897 patients (91.3%) from 7 sites that collect GBS isolates. Among patients with EOD, serotypes Ia (242 [27.3%]) and III (242 [27.3%]) were most common. Among patients with LOD, serotype III was most common (481 [56.2%]), and this increased from 2006 to 2015 from 0.12 to 0.20 cases per 1000 live births (P < .001). Serotype IV caused 53 cases (6.2%) of EOD and LOD combined. The 6 most common serotypes (Ia, Ib, II, III, IV, and V) caused 881 EOD cases (99.3%) and 853 LOD cases (99.7%). No β-lactam resistance was identified; 359 isolates (20.8%) tested showed constitutive clindamycin resistance. In 2015, an estimated 840 EOD cases and 1265 LOD cases occurred nationally.

CONCLUSIONS AND RELEVANCE

The rates of LOD among US infants are now higher than EOD rates. Combined with addressing IAP implementation gaps, an effective vaccine covering the most common serotypes might further reduce EOD rates and help prevent LOD, for which there is no current public health intervention.

The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands

Group B Streptococcus (GBS) colonizes the human lower intestinal and genital tracts and constitutes a major threat to neonates from pregnant carrier mothers and to adults with underlying morbidity. The pathogen expresses cell-surface virulence factors that enable cell adhesion and penetration and that counteract innate and adaptive immune responses. Among these, the complement interfering protein (CIP) was recently described for its capacity to interact with the human C4b ligand and to interfere with the classical- and lectin-complement pathways. In the present study, we provide evidence that CIP can also interact with C3, C3b, and C3d. Immunoassay-based competition experiments showed that binding of CIP to C3d interferes with the interaction between C3d and the complement receptor 2/cluster of differentiation 21 (CR2/CD21) receptor on B cells. By B-cell intracellular signaling assays, CIP was confirmed to down-regulate CR2/CD21-dependent B-cell activation. The CIP domain involved in C3d binding was mapped via hydrogen deuterium exchange–mass spectrometry. The data obtained reveal a new role for this GBS polypeptide at the interface between the innate and adaptive immune responses, adding a new member to the growing list of virulence factors secreted by gram-positive pathogens that incorporate multiple immunomodulatory functions.—Giussani, S., Pietrocola, G., Donnarumma, D., Norais, N., Speziale, P., Fabbrini, M., Margarit, I. The Streptococcus agalactiae complement interfering protein combines multiple complement-inhibitory mechanisms by interacting with both C4 and C3 ligands.

Antenatal and intrapartum nucleic acid amplification test use for group B Streptococcus screening-United States, 2016

Perinatal group B Streptococcus (GBS) disease prevention guidelines in 2010 allowed for processing of screening specimens by nucleic acid amplification tests (NAATs); however, the extent of NAAT use is unknown. A 2016 laboratory survey sent to 10 surveillance sites found that 18.7% of responding laboratories offered NAAT for GBS screening (antenatal only: 7.3%; intrapartum only: 4.1%; both: 3.4%).

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.

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.

Vertical transmission of group B Streptococcus and associated factors among pregnant women: a cross-sectional study, Eastern Ethiopia

Background

Vertically transmitted group B Streptococcus (GBS) causes fetal and neonatal infections. However, there is limited information on the vertical transmission of GBS in low-income countries. This study, therefore, aimed to determine the rate of vertical transmission of GBS and associated factors among pregnant women in Eastern Ethiopia.

Subjects and methods

A cross-sectional, facility-based study was conducted among pregnant women in Harar town, Eastern Ethiopia, from June to October, 2016. GBS positivity of pregnant women was confirmed by culture of rectovaginal swab. Vertical transmission at birth was confirmed by culture on swabs taken from the ear canal, umbilicus, axilla, groin, and nose within 6 hours after birth. Prevalence ratio (PR) along with 95% CI was estimated to examine factors associated with vertical transmission using log binomial regression analysis.

Results

Out of 231 GBS-colonized pregnant women at delivery, 104 births were identified as GBS colonized with a vertical transmission rate of 45.02% and 95% CI: 38.49, 51.68. Of 104 vertical transmission cases, 65 (62.50%) received no intrapartum antibiotic prophylaxis (IAP), 28 (26.92%) received it <4 hours before delivery, and 11 (10.58%) received it ≥4 hours before delivery. Pre-labor rupture of membranes at term (PR: 1.93; 95% CI: 1.04, 3.57), prolonged rupture of the membrane ≥18 hours (PR: 1.76; 95% CI: 1.13, 2.74), intrapartum maternal fever (PR: 1.40; 95% CI: 1.13, 1.75), and IAP received ≥4 hours (PR: 0.17; 95% CI: 0.09, 0.30) were significantly associated with vertical transmission of GBS.

Conclusion

The magnitude of vertical transmission of GBS was very high. However, the rate of adequate IAP received by mothers was very low. Efforts need to be strengthened to screen pregnant women during antenatal care and IAP should be used as necessary. Furthermore, maternal vaccination may provide a feasible strategy to reduce the vertical transmission.

Are postnatal ampicillin levels actually related to the duration of intrapartum antibiotic prophylaxis prior to delivery? A pharmacokinetic study in 120 neonates

OBJECTIVE

To assess ampicillin levels according to the duration of intrapartum antibiotic prophylaxis (IAP).

DESIGN

Prospective cohort single-centre study.

SETTING

Tertiary care centre (Modena, Italy).

PATIENTS

120 neonates≥35 weeks' gestation exposed to IAP.

INTERVENTIONS

Neonates were divided into four groups, according to the duration of IAP prior to delivery: group 1 (n=30; <1 hour), group 2 (n=30; ≥1 and <2 hours), group 3 (n=30; ≥2 and <4 hours) and group 4 (n=30; ≥2 doses, ≥4 hours).

MAIN OUTCOME MEASURES

Blood samples were collected at delivery (from the umbilical cord) and at age 4 hours (from a peripheral vessel).

RESULTS

Median duration of IAP was 121 min (range 7-2045 min). Median ampicillin levels in umbilical cord blood were 10.4 µg/mL (IQR 6.4-14.9) and in peripheral blood were 4.7 µg/mL (IQR 2.8-6.4µg/mL). Umbilical cord blood levels reached a peak approximately 30 min after IAP and then declined significantly (p<0.001). Peripheral blood levels did not differ among study groups. Neonates exposed to a full loading dose (n=115) had peripheral blood levels 2.5-70 times higher than the minimal inhibitory concentration for group B streptococcus. There was no relationship between neonatal ampicillin concentrations and the duration of IAP prior to delivery (β=-0.0003, 95% CI -0.02 to 0.001, p=0.680).

CONCLUSIONS

Ampicillin levels reach a peak in the umbilical cord blood within 30 min of intrapartum administration. After a full loading dose, bactericidal levels persist for at least 4 hours after birth and seem independent of the duration of IAP prior to delivery.

Group B Streptococcal Maternal Colonization and Neonatal Disease: Molecular Mechanisms and Preventative Approaches

Group B Streptococcus (GBS) colonizes the gastrointestinal and vaginal epithelium of a significant percentage of healthy women, with potential for ascending intrauterine infection or transmission during parturition, creating a risk of serious disease in the vulnerable newborn. This review highlights new insights on the bacterial virulence determinants, host immune responses, and microbiome interactions that underpin GBS vaginal colonization, the proximal step in newborn infectious disease pathogenesis. From the pathogen perspective, the function GBS adhesins and biofilms, β-hemolysin/cytolysin toxin, immune resistance factors, sialic acid mimicry, and two-component transcriptional regulatory systems are reviewed. From the host standpoint, pathogen recognition, cytokine responses, and the vaginal mucosal and placental immunity to the pathogen are detailed. Finally, the rationale, efficacy, and potential unintended consequences of current universal recommended intrapartum antibiotic prophylaxis are considered, with updates on new developments toward a GBS vaccine or alternative approaches to reducing vaginal colonization.