ReviewIntrapartum antibiotic prophylaxis for the prevention of perinatal group B streptococcal disease: Experience in the United States and implications for a potential group B streptococcal vaccine
Highlights
► We reviewed intrapartum prophylaxis impact on newborn group B streptococcal disease. ► US uptake of prenatal screening and intrapartum antibiotics was rapid and widespread. ► The incidence of invasive early-onset GBS disease decreased by more than 80%. ► From 1994 to 2010 over 70,000 cases of newborn invasive GBS disease were prevented. ► Current prevention limitations might be addressed by a maternal GBS vaccine.
Section snippets
History of group B streptococcal disease and prevention interventions
The bacteria group B Streptococcus (GBS) emerged as the leading cause of infection in newborns in the United States in the 1970s. Case series reported fatality rates as high as 50%, with pneumonia and meningitis the leading clinical syndromes. Early-onset GBS infections (onset within the first week of life) result predominantly from vertical transmission of GBS from colonized mothers during the intrapartum period whereas infections from one week to 90 days of age (late-onset infections) result
Development and evolution of GBS prevention policy
Prevention of early-onset GBS disease crosses clinical specialty boundaries because a maternal intervention is needed to protect newborns from disease. In 1992 the American Academy of Pediatrics promoted an IAP strategy that focused on maternal screening for GBS colonization, with an emphasis on colonized women with either preterm delivery or prolonged membrane rupture [4]. During the same time period the American College of Obstetricians and Gynecologists advocated an approach that did not
Implementation of prevention, 1996–2002
Successful implementation of an intrapartum prophylaxis strategy is complex and requires strong collaboration between obstetric, clinical laboratory and newborn care providers. Implementation involves two key steps: (1) ascertainment of whether a woman has an indication for IAP; (2) administration of appropriate IAP to women with indications.
Shortly after issuance of the first consensus guidelines, having a newly established hospital policy for GBS prevention was associated with stronger
Implementation of prevention in the era of universal screening
The key steps to successful prevention under a universal screening strategy include reaching a high proportion of women for antenatal screens; correct specimen collection and processing; and implementation of appropriate IAP to women with indications. A large, multistate review of births in 2003 and 2004, shortly after issuance of the first universal screening recommendations, documented rapid, widespread uptake of screening [16]: 85% of women had documented antenatal GBS screening, and 98% of
Impact of IAP and universal screening on perinatal GBS disease
Despite the high incidence of early-onset GBS disease in the pre-prevention era, monitoring disease trends was complicated by the fact that even large hospitals had only a small number of invasive cases annually. This necessitated surveillance in a large catchment area. To this end, in 1990 the Centers for Disease Control and Prevention in collaboration with state partners launched multistate invasive group B streptococcal disease surveillance as part of the Active Bacterial Core surveillance
IAP effectiveness
Direct IAP effectiveness estimates are helpful as a complement to disease trend data, and also provide a context for comparing IAP to other possible prevention strategies such as a GBS vaccine. A case-control analysis of the effectiveness of IAP among mother with obstetric risk factors reported an adjusted effectiveness of 86% (95% confidence interval, 66–94%) against invasive early-onset GBS disease, with slightly lower point estimates for the subgroup of mothers with intrapartum fever and
Maximizing the impact of IAP in the United States
From a review of ABCs invasive early-onset GBS cases that occurred in 2008–2009, we estimated that optimal implementation of prenatal screening and intrapartum prophylaxis could have prevented 31–43% of cases, suggesting that further reduction of the burden of early-onset GBS disease is achievable under current prevention strategies [19]. While the evaluation of laboratory practices for the processing and testing of prenatal screening specimens from the mothers of the cases in that study is
Global experience with IAP
Beyond the US, several industrialized countries have implemented IAP policies. Some (e.g., Spain, Canada, Australia) have adopted indications for prophylaxis similar to the US, and have documented declines similar to the United States [31], [32]. Countries and single hospitals that have adopted risk-based approaches have also documented declines [24]. A recent systematic review of neonatal GBS disease globally found that early-onset GBS disease incidence in countries that used IAP (0.23.1000
GBS vaccine considerations in the setting of widespread IAP
With a trivalent (serotypes 1a, 1b and III) GBS conjugate vaccine currently undergoing Phase II trials in pregnant women (clinicaltrials.gov identifiers NCT01446289, NCT01412801, NCT01193920) it is reasonable to consider factors that might influence the decision to introduce maternal GBS vaccination in a country such as the US where widespread IAP is already in place.
Compared to a serotype-specific maternal vaccine, IAP has certain advantages. First, it is effective against all GBS serotypes;
Conclusions
The experience in the United States has shown that universal screening and IAP for GBS-colonized women comprise a highly effective strategy against early-onset GBS infections that has been very well implemented at the population level. There are shortcomings, however, with the current GBS prevention efforts. Some of the limitations can be overcome by maximizing adherence to recommended practices, and there is room to further reduce the burden of early-onset GBS disease through improved
Acknowledgements
We acknowledge the hard work and contributions of all the members of the Active Bacterial Core surveillance GBS team over the years.
Conflicts of interest statement: None declared.
References (42)
- et al.
Effects of hospital policies based on 1996 group B streptococcal disease consensus guidelines. The active bacterial core surveillance team
Obstet Gynecol
(2000) - et al.
Antibiotic use in pregnancy and drug-resistant infant sepsis
Am J Obstet Gynecol
(1999) - et al.
Neonatal sepsis and death caused by resistant Escherichia coli: possible consequences of extended maternal ampicillin administration
Am J Obstet Gynecol
(1999) - et al.
Effects of intrapartum antimicrobial prophylaxis for prevention of group-B-streptococcal disease on the incidence and ecology of early-onset neonatal sepsis
Lancet Infect Dis
(2003) - et al.
Group B streptococcal disease in infants aged younger than 3 months: systematic review and meta-analysis
Lancet
(2012) - et al.
The infectious origins of stillbirth
Am J Obstet Gynecol
(2003) - et al.
Prevention of early-onset neonatal group B streptococcal disease with selective intrapartum chemoprophylaxis
N Engl J Med
(1986) - et al.
Prevention of neonatal group B streptococcal disease: intrapartum detection and chemoprophylaxis of heavily colonized parturients
Obstet Gynecol
(1989) - et al.
Group B streptococcus (GBS) and neonatal infections: the case for intrapartum chemoprophylaxis
Aust N Z J Obstet Gynaecol
(1991) Guidelines for prevention of group B streptococcal infection by chemoprophylaxis
Pediatrics
(1992)
Group B streptococcal infections in pregnancy: ACOG's recommendations
ACOG Newslett
Revised guidelines for prevention of early-onset group B streptococcal (GBS) infection. American Academy of Pediatrics Committee on Infectious Diseases and Committee on Fetus and Newborn
Pediatrics
ACOG committee opinion. Prevention of early-onset group B streptococcal disease in newborns. Number 173—June 1996. Committee on Obstetric Practice. American College of Obstetrics and Gynecologists
Int J Gynaecol Obstet
A population-based comparison of strategies to prevent early-onset group B streptococcal disease in neonates
N Engl J Med
ACOG Committee Opinion: number 279, December 2002. Prevention of early-onset group B streptococcal disease in newborns
Obstet Gynecol
Prevention of perinatal group B streptococcal disease: revised guidelines from CDC, 2010
Morb Mortal Wkly Rep
Antibiotic resistance patterns in invasive group B streptococcal isolates
Infect Dis Obstet Gynecol
Cefazolin pharmacokinetics in maternal plasma and amniotic fluid during pregnancy
Am J Obstet Gynecol
Evaluation of universal antenatal screening for group B streptococcus
NEJM 2009
Cited by (218)
Association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis among patients undergoing induction of labor at term
2023, American Journal of Obstetrics and GynecologyGroup B Streptococcus in Pregnancy
2023, Obstetrics and Gynecology Clinics of North AmericaStreptococcus agalactiae (Group B Streptococcus)
2023, Molecular Medical Microbiology, Third EditionCentral nervous system (CNS) infections in pregnancy
2023, The Brain of the Critically Ill Pregnant Woman
- 1
This work was funded solely by the Centers for Disease Control and Prevention.