Comparison of first year of life acute otitis media admissions before and after the 13-valent pneumococcal conjugate vaccine.

BACKGROUND: Acute otitis media (AOM) is a common childhood infection, which is usually managed in the outpatient setting. Yet, the more severe cases are referred for inpatient treatment. We hypothesized that pneumococcal conjugate vaccines (PCVs), administered during the first year of life, would decrease AOM admissions rate in this age group. We studied the characteristics of infants admitted with AOM and acute mastoiditis (AM) in the PCV13 era, routinely given from November 2010 to all infants.

METHODS: Charts of infants ≤1 year that were hospitalized during 1/1/2010-31/12/2015 with AOM, with or without AM, were retrieved using hospitalization codes. We compared 2010-11 (transition years, from PCV7 to PCV13) to 2012-15 (post-PCV13 marketing years).

RESULTS: AOM was the primary/secondary discharge diagnosis in ∼4% of all admitted infants ≤1 year. Boys had more admissions than girls (62% vs 38%). Accuracy of AOM diagnoses substantially increased in the post-marketing years. The average hospitalization duration slightly shortened, from 3.21 (2010-11) to 2.99 days (2012-15) (p = 0.52). Despite considerably modest pre-admission antibiotic treatment rate (<30%), AM was infrequent (∼3.4% of AOM admissions). Amoxicillin was the most common antibiotic therapy given before admission and during hospitalization. The number of myringotomies, usually reserved for treatment failure cases, significantly declined, and there were almost no cases of resistant bacteria. Respiratory syncytial virus was detected in ∼20% of collected respiratory samples, and influenza A/B viruses in ∼8%.

CONCLUSIONS: AOM is still a major cause for hospitalization of infants in the PCV13 era. Yet, complications are infrequent, and AM rate is low.