Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Pneumococcal Meningitis in US Children

Abstract

Background. The impact of 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal meningitis (PM) in US children is unknown. We compared the serotype distribution, antibiotic susceptibility, hospital course, and outcomes of children with PM 3 years before and 3 years after the introduction of PCV13. Methods. We identified patients ≤18 years of age with PM at 8 children's hospitals in the United States. Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Clinical data were abstracted from medical records. Patients were divided into 3 subgroups: pre-PCV13 (2007–2009), transitional year (2010), and post-PCV13 (2011–2013). Categorical variables were analyzed by the χ² test and continuous variables by the Mann--Whitney U test. Results. During the study period, 173 of 1207 episodes (14%) of invasive pneumococcal disease were identified as PM; 76 of 645 (12%) were during 2007–2009 and 69 of 394 (18%) during 2011–2013 (50% increase; P = .03). The proportion of PCV13 serotype cases decreased from 54% in 2007–2009 to 27% in 2011–2013 (P = .001). Non-PCV13 serotype cases represented 73% of the isolates in 2011–2013. Isolates with ceftriaxone minimum inhibitory concentration ≥1 µg/mL decreased (13% to 3%) from 2007–2009 to 2011–2013 (P = .03). No significant differences were identified for hospital course or outcome, with the exception that a greater proportion of patients had subdural empyema and hemiparesis in 2011–2013. Conclusions. After the introduction of PCV13, the number of cases of PM in children remained unchanged compared with 2007–2009, although the proportion of PCV13 serotypes decreased significantly. Serotype 19A continued to be the most common serotype in 2011–2013. Antibiotic resistance decreased significantly. Morbidity and case-fatality rate due to PM remain substantial.