Late-onset Group B Streptococcal Meningitis, Potential Effectiveness of a Vaccine by Maternal Immunization?

Abstract

To the Editors: We read with interest the recent article published in the December issue of The Pediatric Infectious Disease Journal, by Edwards et al.1 The authors suggest that third-trimester maternal group B streptococcal (GBS) immunization could substantially reduce the burden of late-onset GBS disease in the United States. Meningitis represents 60% of late-onset GBS invasive disease and is associated with death in 17.7% of cases and frequently permanent sequelae.2 In 2001, the Pediatric Infectious Diseases Group of the French Pediatrics Society (GPIP/ACTIV of the SFP) established an active national surveillance network to monitor the clinical and biologic features of bacterial meningitis.3 From 2001 to 2013, 5567 cases of meningitis were collected: 14.1% (n = 784) were GBS meningitis, most late-onset (69.9%, n = 548). Using this large cohort, we compared our data to those published by Edwards et al. We excluded from our analysis cases without available gestational age (n = 33) and stratified our 515 cases by gestational age at birth and age at onset of meningitis (same definition in the Edwards et al study). Isolates of GBS were identified by standard methods in the microbiology laboratory of each hospital, and some were sent to the National Reference Center (CNR-Strep, Paris) for serotype analysis.4 We highlight several of our findings. First, among the 454 cases (88.2%) with gestation of at least 35 weeks (79.4% at term and 8.8% near term), 78.9% of illnesses occurred within 6 weeks of life (vs. 72% in the Edwards et al study). This rate increased to 92.7% for children with meningitis developing within the first 9 weeks of life. Moreover, we found similar results to the Edwards et al study in terms of age at diagnosis for infants born at ≥35 weeks’ gestation (median 26 days), who were significantly younger than infants born at <35 weeks’ gestation (median 43 days, P < 0.0001). Among infants born at ≥35 weeks’ gestation, 57.9% became ill at age 7 to 29 days, 32.6% at 30 to 59 days and 9.5% at 60 to 89 days (Fig. 1). In our series, among 210 available GBS strains, the most frequent GBS capsular type causing late-onset meningitis was type III, 82.4% and 8.6% were type Ia GBS, as mentioned by Edwards et al.FIGURE 1: Distribution of 515 infants with late-onset GBS meningitis by gestation at birth and age at disease onset.Our data, with the largest cohort (515 cases) of GBS meningitis, provide consistent results and confirm those found in the recent Edwards et al study. We thus support the assumption regarding the potential effectiveness of a GBS vaccine administered during the third trimester of pregnancy to substantially reduce late-onset GBS meningitis in France. Because meningitis often results in death or permanent disability, the preventive measures to decrease the incidence of late-onset GBS meningitis are crucial.5–7 Despite intrapartum antibiotic prophylaxis, a few cases of early-onset GBS disease continue to occur. We hope protection induced by this vaccine will prevent these residual early-onset cases. ACKNOWLEDGMENTS The authors are grateful to pediatricians and microbiologists of the Observatoire National des méningites network. Corinne Levy, MD Association Clinique et Thérapeutique Infantile du Val de Marne (ACTIV) Pediatric Infectious Disease Group Saint Maur des Fossés, France Clinical Research Center Centre Hospitalier Intercommunal de Créteil Université Paris EstIMRB- GRC GEMINI Créteil, France Stéphane Bonacorsi, MD Univ Paris Diderot, Sorbonne Paris Cité Service de Microbiologie Hôpital Robert-Debré Paris, France Stéphane Béchet, MSc ACTIV Saint-Maur des Fossés, France Claire Poyart, MD, PhD Assistance Publique Hôpitaux de Paris Centre National de Référence des Streptocoques Service de Bactériologie Hôpitaux Universitaires Paris Centre Université Paris Descartes Sorbonne Paris Cité Paris, France Robert Cohen, MD ACTIV Pediatric Infectious Disease Group Saint Maur des Fossés, France Clinical Research Center Centre Hospitalier Intercommunal de Créteil Unité Court Séjour, Petits Nourrissons Service de Néonatologie Centre Hospitalier Intercommunal de Créteil Université Paris EstIMRB- GRC GEMINI Créteil, France