When Co-colonizing the Nasopharynx Haemophilus influenzae Predominates Over Streptococcus pneumoniae Except Serotype 19A Strains to Cause Acute Otitis Media

Of 368 acute otitis media (AOM) cases among 7-valent pneumococcal conjugate-vaccinated children, 43.5% were colonized by multiple otopathogens in the nasopharynx but only 7.1% experienced polymicrobial AOM. When co-colonization occurred, Haemophilus influenzae predominated over all Streptococcus pneumoniae strains except 19A strains to cause AOM. Haemophilus influenzae and Streptococcus pneumoniae both predominated over Moraxella catarrhalis to cause AOM.