Nanduri SA, et al. - In the United States from 2006 to 2015 to inform intrapartum antibiotic prophylaxis (IAP) guidelines and vaccine development, authors assessed the incidence rates, characteristics of the case, resistance towards antimicrobials, and serotype distribution of early-onset disease (EOD; with onset at 0-6 days of life) and late-onset disease (LOD; with onset at 7-89 days of life). They observed a higher rate of LOD than EOD rates among US infants. Hence, they suggested that management with an effective vaccine (covering the most common serotypes) be done in combination with addressing IAP implementation gaps.

Methods

• In this study, they conducted active population-based and laboratory-based surveillance for invasive group B Streptococcus (GBS) disease through Active Bacterial Core surveillance in selected counties of 10 states across the United States.
• From 2006 to 2015 , they involved inhabitants of Active Bacterial Core surveillance areas, younger than 90 days and had invasive GBS disease.
• They analyzed data from December 2017 to April 2018.
• These residents were exposed to group B Streptococcus isolated from a normally sterile site.
• They considered EOD and LOD incidence rates and associated GBS serotypes and antimicrobial resistance as main outcomes and measures.

Results

• They recognized 1277 cases of EOD and 1387 cases of LOD in the Active Bacterial Core surveillance program.
• They observed a decline in EOD incidence from 0.37 to 0.23 per 1000 live births (P < .001), and stable LOD rate (mean, 0.31 per 1000 live births) from 2006 to 2015.
• A fraction of 617 (48.3%) had no indications for IAP and did not receive it, and 278 (21.8%) failed to receive IAP despite having indications among the mothers of 1277 neonates with EOD.
• Serotype data for 1743 of 1897 patients (91.3%) from seven sites collecting GBS isolates were available.
• They recorded serotypes Ia (242 [27.3%]) and III (242 [27.3%]) were the most common among those isolates.
• From 2006 to 2015, serotype III was most commonly noted (481 [56.2%]) with an increment from 0.12 to 0.20 cases per 1000 live births (P < .001) among candidates with LOD.
• They noted 53 cases (6.2%) of combined EOD and LOD due to serotype IV.
• A number of 881 EOD cases (99.3%) and 853 LOD cases (99.7%) were incidents due to the 6 most common serotypes ie, Ia, Ib, II, III, IV, and V.
• About 20.8% of isolates (359) tested were recorded with constitutive clindamycin resistance, but no β-lactam resistance was recognized.
• They noted approximately 840 EOD cases and 1265 LOD cases nationally in 2015.