Prevention of group B streptococcus early-onset neonatal sepsis: comparison of the Center for Disease Control and prevention screening-based protocol to a risk-based protocol in infants at greater than 37 weeks' gestation

The microbial pathology of maternal perinatal sepsis: A single-institution retrospective five-year review

INTRODUCTION

Greater than half of in-hospital maternal deaths are caused by sepsis, a condition that occurs when infection exceeds local tissue containment and results in organ dysfunction. Determining the source of infection can be challenging. Microbiological cultures of the uterine cavity are often difficult to obtain, so antimicrobial susceptibility results may not be available to guide treatment. The aim of this retrospective study was to assess the potential clinical value of microbiology samples used in the maternal "septic screen" of patients in an Irish maternity hospital.

METHODS

A review was completed of all maternal "septic screen" (i.e., high vaginal swabs, placenta swabs, blood cultures, throat swabs and urine samples) microbiology results from July 2016 to December 2021.

RESULTS

In the relevant period, 845 patients were subject to a "septic screen", of whom 430 also had a placental swab collected. These 430 patients comprise our study population. 2% of blood cultures yielded potential pathogens, compared with 37%, 33%, 9% and 7% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens. 95% of blood cultures were sterile, compared with 52%, 0%, 0% and 53% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens.

CONCLUSION

Of the five microbiological specimen types examined, placental swabs yielded the highest number of potential pathogens. Our results suggest that placental swabs are useful specimens for detecting potential pathogens from the uterine cavity, the most common source of perinatal infections.

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.

Universal versus Risk-Based Management of Unknown Group B Streptococcus Status at Term

Objectives  This article estimates and compares public health costs of universal versus risk-based intrapartum antibiotic prophylaxis (IAP) administration for women with unknown Group B streptococcus (GBS) status at term. Study Design  The annual number of women in the U.S. who are: unscreened for GBS, without risk factors, delivering vaginally, multiparous, and eligible for discharge within 24 hours was estimated. Under the risk-based strategy, women and neonates were assumed to stay another day for observation and incur the cost of an additional 24-hour stay. With universal IAP administration, women delivering without complications were assumed to be discharged within 24 hours, with an incurred cost of penicillin. Results  The estimated cost for the risk-based management of unscreened women at term without rupture of membranes (ROM) > 18 hours ranged from $468,886,831 to $850,556,179. Similarly, the cost of managing unscreened women without maternal intrapartum fever (MIF) ranged from $742,024,791 to $919,269,233. Alternatively, universal IAP administration costs ranged from $470,107,674 to $568,359,086.5. Cost comparisons yielded an equivalence or up to a 33.2% reduction in cost, and 36.6 to 38.2% reduction in cost for women without ROM > 18 hours and MIF, respectively. Conclusions  Universal IAP may be cost saving due to the reduction in extended hospitalizations for neonates and healthy mothers.

Risk-based approach versus culture-based screening for identification of group B streptococci among women in labor

OBJECTIVE

To compare a risk-based and culture-based screening approach for identification of group B streptococci (GBS) vaginal colonization using an intrapartum rectovaginal culture as the reference standard.

METHODS

Pregnant women attending the prenatal clinic at Lillebaelt Hospital, Kolding, Denmark, between April 1, 2013, and June 30, 2014, were invited to participate in a prospective observational study. For prepartum culture-based screening, vaginal and rectal culture samples were obtained and, for reference, standard, paired vaginal and rectal culture samples were collected during labor. Risk factors for risk-based screening were previous early-onset GBS, GBS bacteriuria during pregnancy, maternal temperature ≥38.0°C intrapartum, and rupture of membranes for more than 18 hours.

RESULTS

The intrapartum rectovaginal GBS colonization rate was 30% (32/108) among participants with risk factors and 15% (123/794) among participants without risk factors. Culture-based screening demonstrated a sensitivity, specificity, positive predictive value, negative predictive value, and positive likelihood ratio in predicting intrapartum GBS carriage of 78% (95% confidence interval [CI] 71-84), 95% (94-97), 78% (70-84), 95% (94-97), and 17 (12-23), respectively; for risk-based screening, these values were 21% (15-28), 90% (87-92), 30% (22-38), 85% (83-86), and 2 (1-3), respectively.

CONCLUSIONS

Culture-based screening performed considerably better than a risk-based approach in identifying intrapartum GBS colonization.

Group B streptococcal immunisation of pregnant women for the prevention of early and late onset Group B streptococcal infection of the neonate as well as adult disease

INTRODUCTION

Early onset neonatal Group B streptococcal disease is preventable. Intrapartum antibiotic prophylaxis has resulted in a significant reduction in neonatal mortality and morbidity. National guidelines for the selection of women eligible for intrapartum antibiotic prophylaxis, whether screening-based or risk-based, differ according to the local burden of disease. Despite the introduction of intrapartum antibiotic prophylaxis, there remains a significant burden of disease, which can be resolved by better adherence to guidelines, rapid identification of maternal colonization or in the future, vaccination. Areas covered: The introduction of a vaccine to women in the third trimester is likely to further reduce the burden of disease and provide benefits beyond the prevention of early neonatal disease, including meningitis and disability following late onset disease. Development of specific polyvalent vaccines continues, but testing has challenges and may require surrogate markers or molecular-based techniques to manipulate antigenicity and immunogenicity. Expert commentary: Group B streptococcal vaccination using conjugated polyvalent vaccines against the major disease causing serotypes of Group B streptococcus, either alone, or in combination with a policy of intrapartum antibiotic prophylaxis, may decrease the burden of Group B streptococcus beyond that achieved by current use of intrapartum antibiotic prophylaxis alone.

Universal screening vs. risk-based strategy for prevention of early-onset neonatal Group-B streptococcal disease

OBJECTIVE

To evaluate the difference between universal screening and risk-based strategies in the prevention of early-onset Group-B streptococcal (EOGBS) disease.

SUBJECTS

Cases of EOGBS disease from 2003 to 2009 were identified by a search of the microbiology laboratory's computerized database.

INTERVENTIONS

Maternal screening for Group-B Streptococci was done for all pregnant women by taking rectovaginal swabs and urine culture at 35-37 weeks of gestation and for all high-risk cases at the time of presentation.

RESULTS

From 2003 to 2009, a total of 87,260 live births were recorded, 1948 neonates were very low-birth weight. We reviewed labor and delivery records for 1268 live births randomly sampled from total live births. Forty-five cases of EOGBS disease were identified during the period of study (overall incidence of 0.51 cases per 1000 live births).

Pilot study to prevent early-onset Group B Streptococcal disease in newborns

PURPOSE

The purpose of this study was to: 1) examine the occurrence of early-onset Group B Streptococcal (GBS) disease in newborns, and 2) describe the relationship between early-onset GBS disease in the newborn and the number of doses of antibiotics the mother received before delivery.

SUBJECTS

Women with a positive Group B Streptococcus screening culture were added to the study based on the inclusion criteria and further grouped based on the number of doses of intrapartum antibiotics received. The mothers and infants in Group 1 received only 1 dose of intrapartum antibiotics; Group 2 received > or =2 doses of intrapartum antibiotics. The sample consisted of a total of 128 women and their infants.

DESIGN AND METHODS

This pilot study used a descriptive correlational design. Data were obtained over a 6-month period by a retrospective chart review. Descriptive statistics were used to characterize the demographic data and chi(2) statistical analysis was done to compare the frequency of early-onset GBS disease in each group to determine if there were differences between groups.

RESULTS

The Pearson chi(2) value for comparing the 2 groups was 0 with 1 degree of freedom indicating no difference of probability outcome between the 2 groups.

CONCLUSIONS

There were no differences found in the incidence of early-onset GBS disease in newborns when a GBS positive pregnant woman received 1 or 2 doses of intrapartum antibiotics. These data provide further supporting evidence for the Centers for Disease Control and Prevention's recommendations that were based on the premise that vertical transmission of GBS will be greatly reduced by administration of 1 dose of intrapartum antibiotics at least 4 hours before delivery to expectant mothers.

Early neonatal streptococcal infection

OBJECTIVE

To determine the incidence of early onset Group B Streptococcal (GBS) infection in infants born over a two year period and to determine the outcome of sepsis evaluation in infants born to mothers with GBS colonization.

METHODS

The charts of infants born to mothers with GBS colonization were reviewed for details of sepsis evaluation and management. The microbiology records were used to identify proven cases of GBS septicemia and meningitis in neonates born during the study period.

RESULTS

Out of a total of 4636 live births in 2 years, there was one infant with culture-proven GBS septicemia, an incidence of 0.2 per 1000 live births. During the study period 83 infants were born to mothers who were known to have GBS carriage at the time of delivery. 73 out of these 83 infants (88%) had sepsis evaluation and received empirical parenteral penicillin for at least 5 days. There were no cases of blood culture-proven GBS sepsis among these 83 infants. However, there were 2 cases of probable sepsis giving an attack rate of 2.4%. All the three infants with definite or probable sepsis were preterm; there were no deaths among these affected infants.

CONCLUSION

The overall incidence of early onset GBS sepsis was found to be low when compared to previous reported studies. The strategy of sepsis evaluation and management was found to be effective in preventing death and definite GBS septicemia in infants born to GBS colonized mothers.

State of the science: neonatal bacterial infection in the early 21st century

Bacterial infections continue to cause significant neonatal morbidity and mortality, especially in small preterm neonates in the neonatal intensive care unit. Maternal and newborn risk factors can be used to prevent newborn infection and initiate early clinical assessments, laboratory diagnostic tests, and antimicrobial agent therapies. Early-onset and late-onset infections have different clinical patterns; however, each must be recognized as soon as possible in order to optimize outcomes. Antibiotics have long been the mainstay of treatment but organism resistance and weak immune system functioning of very premature newborns makes treatment challenging. Research continues on other markers for infection that may lead to more rapid diagnosis. The discovery of new therapies to improve newborn immune system function promises further improvement in outcomes of newborn infection. This article gives an overview of the state of diagnosis and treatment of newborn infection.

The Prevention of Early-Onset Neonatal Group B Streptococcal Disease

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Peripartum transmission of penicillin-resistant Streptococcus pneumoniae

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis. We present a recent case of S. pneumoniae bacteremia acquired on the first day of life in a neonate born at 30 weeks of gestation to a mother without prenatal care who had prolonged rupture of the membranes and received intravenous ampicillin prior to delivery. The isolate was resistant to penicillin, with a MIC of the drug of 4 microg/ml. The child responded to a 7-day course of intravenous vancomycin. S. pneumoniae was recovered from the vagina of the mother on a swab culture collected prior to delivery, and isolates from mother and child were confirmed to be identical on the basis of pulsed-field gel electrophoresis. Although neonatal sepsis due to the peripartum transmission of S. pneumoniae is rare, this case highlights the concern that increasing efforts to prevent group B streptococcus neonatal disease may lead to an increase in neonatal infections due to resistant organisms.

Neonatal bacterial sepsis

Neonatal bacterial infection is a significant cause of morbidity and mortality despite improved survival of premature newborns, better understanding of the pathophysiology of sepsis, advances in supportive care, and more potent antibacterial agents. Early recognition and implementation of appropriate therapy offers the best outcome, and careful assessment of the newborn is essential. Current methods to detect signs of sepsis and to identify the causative microorganism are not 100% sensitive and precise. Continued research on other indicators may yield better diagnostic methods and therapy in the future. Research is necessary to identify the most sensitive markers for diagnosis of sepsis and methods of immune enhancement that are safe and effective.

Early-onset group B streptococcal infection after a combined maternal and neonatal group B streptococcal chemoprophylaxis strategy

OBJECTIVE

In January 1995, a combined maternal and neonatal protocol for prevention of early-onset group B streptococcal (GBS) infection was implemented that consisted of a risk factor-based approach for maternal intrapartum chemoprophylaxis using ampicillin combined with a single intramuscular dose of penicillin given to all newborns within 1 hour of delivery. The objective of this study was to review the cases of early-onset GBS infections that occurred from 1995 to 1999 to identify factors associated with their continued occurrence despite implementation of a GBS chemoprophylaxis protocol.

METHODS

Infants <or=72 hours of age with early-onset GBS infection born at Parkland Memorial Hospital in Dallas from January 1995 to December 1999 were identified through a prospective laboratory-based surveillance system. Maternal and infant medical records were reviewed for clinical and demographic data.

RESULTS

There were 32 cases (0.47/1000 live births) of early-onset GBS infection for the 5-year period. This represented a 76% reduction compared with the rate from 1986 to 1994 (1.95/1000), when there was no protocol for GBS chemoprophylaxis. Thirteen cases (41%) did not have any identifiable maternal risk factor. Of the 19 cases (59%) with risk factors, maternal intrapartum fever was the most frequent (15 [79%]), followed by prematurity (6 [32%]) and prolonged rupture of membranes (6 [32%]). Among the 19 mothers with risk factors, 15 (79%) mothers received intrapartum chemoprophylaxis, and 12 (80%) of the 15 mothers had intrapartum fever. Only 33% of mothers with risk factors received >or=2 doses of intrapartum chemoprophylaxis, and among those with intrapartum fever, 25% received >or=2 doses. None of the 32 infants with early-onset GBS infection received the combination of intrapartum ampicillin and postnatal penicillin.

CONCLUSIONS

A combined obstetric and neonatal chemoprophylaxis protocol significantly reduced early-onset GBS infection. Maternal intrapartum fever was the most frequent risk factor associated with failure of chemoprophylaxis.

The role of intrapartum fever in identifying asymptomatic term neonates with early-onset neonatal sepsis

OBJECTIVE

To assess the role of intrapartum fever in identifying asymptomatic term neonates with early-onset neonatal sepsis.

STUDY DESIGN

Retrospective review of all term neonates with sepsis over a 7-year period to evaluate the significance of symptoms at delivery and intrapartum sepsis risks factors in identifying neonates with sepsis.

RESULTS

Fifty-three of 90 term neonates with sepsis (59%) were asymptomatic at delivery. Thirty-five of 53 asymptomatic term neonates (66%) met criteria for sepsis evaluations and 18 (34%) were evaluated when symptoms developed after delivery. Among the 35 asymptomatic term neonates meeting criteria for sepsis evaluations, 14 (40%) had evaluations because of intrapartum fever. Thus, 14 of 53 (26%) asymptomatic term neonates with sepsis (30% of GBS sepsis and 11% of non-GBS sepsis) would not have been evaluated if intrapartum fever were ignored.

CONCLUSION

Over half of term neonates with sepsis were asymptomatic at delivery. Intrapartum fever was helpful in identifying over a quarter of asymptomatic term neonates with sepsis.

A population-based comparison of strategies to prevent early-onset group B streptococcal disease in neonates

BACKGROUND

Guidelines issued in 1996 in the United States recommend either screening of pregnant women for group B streptococcal colonization by means of cultures (screening approach) or assessing clinical risk factors (risk-based approach) to identify candidates for intrapartum antibiotic prophylaxis.

METHODS

In a multistate retrospective cohort study, we compared the effectiveness of the screening and risk-based approaches in preventing early-onset group B streptococcal disease (in infants less than seven days old). We studied a stratified random sample of the 629,912 live births in 1998 and 1999 in eight geographical areas where there was active surveillance for group B streptococcal infection, including all births in which the neonate had early-onset disease. Women with no documented culture for group B streptococcus were considered to have been cared for according to the risk-based approach.

RESULTS

We studied 5144 births, including 312 in which the newborn had early-onset group B streptococcal disease. Antenatal screening was documented for 52 percent of the mothers. The risk of early-onset disease was significantly lower among the infants of screened women than among those in the risk-based group (adjusted relative risk, 0.46; 95 percent confidence interval, 0.36 to 0.60). Because women whose providers had no strategy for prophylaxis may have been misclassified in the risk-based group, we excluded all women with risk factors and adequate time for prophylaxis who did not receive antibiotics. The adjusted relative risk of early-onset disease associated with the screening approach in this secondary analysis was similar--0.48 (95 percent confidence interval, 0.37 to 0.63).

CONCLUSIONS

Routine screening for group B streptococcus during pregnancy prevents more cases of early-onset disease than the risk-based approach. Recommendations that endorse both strategies as equivalent warrant reconsideration.

Group B streptococci during pregnancy and infancy

Group B streptococcus (Streptococcus agalactiae) is still of great relevance in the perinatal period, although maternal antimicrobial prophylaxis has significantly reduced the rate of culture-confirmed invasive infection in neonates. This strategy, however, raises considerable concern because preterm delivery or late-onset sepsis cannot be prevented, and antibiotic resistance is increasing worldwide. Several advances in the development of conjugate vaccines and in research on virulence factors and pathways involved in the immune response to group B streptococcus have been accomplished, some of which might reach clinical practice in the near future.