Epidemiology of Invasive Early-Onset and Late-Onset Group B Streptococcal Disease in the United States, 2006 to 2015

Abstract

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.

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

“…Results. The rate of neonatal sepsis among the different groups in this study was notably higher than some of the rates quoted in the literature [1,10,16,17]. This is primarily related to two factors.…”

“…The estimated incidence of term early-onset neonatal sepsis is 0.77 to 1 case per 1000 live births, with GBS remaining the most frequent pathogen in term infants [17]. The rate of early-onset GBS sepsis for term neonates is estimated at 0.23 per 1000 live births [10]. The incidence rates in those studies were calculated using case counts from the Active Bacterial Core surveillance program as the numerator and the number of live births extracted from state vital records and national vital statistics reports as the denominator [10].…”

“…The rate of early-onset GBS sepsis for term neonates is estimated at 0.23 per 1000 live births [10]. The incidence rates in those studies were calculated using case counts from the Active Bacterial Core surveillance program as the numerator and the number of live births extracted from state vital records and national vital statistics reports as the denominator [10]. As such, those surveillance studies are aimed at assessing the burden of disease in the overall population, while the aim of this study was to evaluate specific subpopulations and in this context the rates were noted to be different as expected.…”

“…CDC guidelines identify asymptomatic infants born to mothers who were colonized with GBS but received <4 hours of IAP, as at-risk for sepsis [4,9]. A recent multistate surveillance study showed that around 70% of cases of early-onset GBS disease were neonates born to women who did not receive IAP and another 15% were among women who received IAP for <4 hours [10]. Among women who had <4 hours of IAP, more than 50% were admitted to the hospital for >5 hours and would have had an opportunity to receive IAP for an adequate duration.…”

Group B Streptococcal Bacteriuria in Pregnancy: An Evidence‐Based, Patient‐Centered Approach to Care

“…8,9 Following implementation of universal screening and intrapartum prophylaxis in the United States, the rate of neonatal deaths from early-onset GBS disease decreased from 1.8 cases per 1000 births in 1990 to 0.23 cases per 1000 live births in 2015. 8 Despite national guidelines for universal screening for GBS colonization, some women may question or decline standard screening and management recommendations. Midwives and other perinatal care providers may need to customize their care to provide education and support to assist women in achieving an informed choice that reflects both best available evidence and a woman's unique values and preferences.…”