Abstract
Objectives:
(1) Describe the changing trends in mastoiditis incidence and bacteriology in the pneumococcal conjugate vaccine (PCV) era.
Methods:
PCV-7 and PCV-13 have been gradually implemented in the Israeli national immunization program in 2009 and 2010, respectively. We retrospectively identified children aged 0-6 years who had middle ear cultures obtained from “severe” acute otitis media (AOM) episodes, defined as AOM requiring tympanocentesis or presenting with spontaneous otorrhea, during the years 2008-2013. Of those, we identified children with acute mastoiditis. Data were extracted for demographic, clinical and microbial information.
Results:
Data from 295 eligible AOM episodes reported in 279 children were collected. Of those, 56 children with 57 episodes of acute mastoiditis were identified. Of these 36 were boys (64%) and 37 (66%) were <2 years old. During the pre-PCV and the PCV introduction period (January 2008-November 2010), mastoiditis incidence rate was significantly higher than the post-PCV introduction era (December 2010-December 2013) incidence, 0.23 versus 0.16/“severe” AOM episode, respectively (P = .04). Mastoiditis developed despite adequate systemic antibiotic therapy for AOM in 28 (49%) patients. Of the 21 (37%) positive cultures, Streptococcus pneumoniae was the most common bacteria, which was solely isolated in 17 (81%) episodes and in combination of Haemophilus influenzae in 1 (5%) episode. Notably, there were no isolates of S pneumoniae from mastoiditis patients following the first year after PCV-13 introduction.
Conclusions:
Mastoiditis incidence complicating “severe” AOM decreased after the introduction of PCVs, which can be directly attributed to their effectiveness in reducing pneumococcal-related AOM burden and complications.