Incidence and bacterial etiology of acute otitis media in children in the pneumococcal conjugate vaccine era: A systematic literature review and meta-analysis

BACKGROUND: This systematic literature review (SLR) evaluated the incidence and bacterial etiology of acute otitis media (AOM) in children. METHODS: statistic. FINDINGS: The SLR identified 37 publications reporting on AOM incidence, of which 25 were included in the meta-analysis, and 34 publications reporting on prevalence of bacterial pathogens in middle ear fluid. AOM IRs (per 100 person-years) were 18.77 in ≤2-year-olds, 10.39 in >2 to ≤5-year-olds, and 5 years. In ≤2-year-olds, AOM IR was 16.07 among those who received a pneumococcal conjugate vaccine (PCV) and 34.26 among those who did not. Among ≤2-year-olds, Hi contributed to 31.81% of AOM cases, followed by 19.35% for Spn, and 3.00% for Mcat. Across all ages, frequently reported Spn serotypes among Spn-AOM cases were 3 (10.81%), 19F (10.65%), 19A (10.43%), 23A (4.60%), 35B (4.38%), and 21 (3.23%) whereas 78.2% of Hi-AOM cases were caused by non-typeable Hi (NTHi). INTERPRETATION: A substantial AOM burden in children remains during the PCV era, with disproportionately higher incidence among children ≤2 years old. Select PCV- and non-PCV pneumococcal serotypes and NTHi have contributed significantly to the AOM burden. Vaccines offering improved protection against remaining PCV serotypes, emerging pneumococcal serotypes, and NTHi are needed to reduce the existing AOM burden in children.