Pediatric mastoiditis in the pneumococcal conjugate vaccine era: symptom duration guides empiric antimicrobial therapy.

Background: The microbiology of acute otitis media has changed in the heptavalent pneumococcal conjugate vaccine (PCV) era. We hypothesize similar changes with pediatric mastoiditis.

Objectives: To compare the etiology of mastoiditis in the pre-PCV (January 1995-December 2000) and post-PCV (January 2001- April 2005) eras to guide empiric antimicrobial therapy in the pediatric emergency department.