Acute Otitis Media in Young Children Today

William T. Basco, Jr, MD, MS


November 15, 2017

Comparing the Epidemiology of Acute Otitis Media in Children

In a recent study, Kaur and colleagues[1] described the epidemiology of acute otitis media (AOM) in young children during the pneumococcal conjugate vaccine era, and compared their findings from this relatively recent decade with previous data.[2]

This 10-year study (2006-2016) prospectively followed 615 children from age 6-36 months. All study children had been full-term and healthy at birth. Routine visits took place every 3 months until age 18 months, then yearly. The children were also seen for any episode of AOM developing between routine visits.

A strict definition of AOM was applied, and middle-ear fluid specimens for culture were obtained from most children. The diagnosis of AOM was made by one of two validated examiners. Criteria included tympanic membranes that were bulging or opacified, a cloudy or purulent effusion, and reduced mobility.

Children were designated "otitis prone" if they experienced four AOM episodes in 1 year or three episodes within 6 months. AOM was treated with a 5-day course of amoxicillin/clavulanate, owing to local resistance patterns that suggested high rates of beta-lactamase production among Haemophilus influenzae and Moraxella catarrhalis isolates. Treatment failure was defined as evidence of AOM within 2 weeks of beginning antibiotic treatment.

Enrollment data included demographic risk factors for AOM, family history of AOM, breastfeeding, history of atopic disease, and vaccination status. Of note, all children had received four doses of either the 7-valent or 13-valent pneumococcal conjugate vaccine (depending on year of enrollment), and booster doses at age 15 months.

Study Findings

The group of 615 infants studied included a slight predominance (52.7%) of boys, 41.6% had a family history of ear infection, 13% had been exposed to tobacco smoke, 25.7% had a history of atopic disease, and 26.3% were never breastfed. Multivariable analysis demonstrated that daycare attendance, being of non-Hispanic white race, and the presence of atopic disease were all associated with a greater risk of experiencing at least one episode of AOM, as did having siblings or a family history of AOM. Male sex, a family history of AOM, and attendance at daycare were predictive of recurrent AOM.

Several general trends were observed with respect to bacteriology. First, approximately one fourth of the cultures grew no bacterial pathogen. In general, the proportion of pneumococcal isolates declined over time, whereas M. catarrhalis isolates increased. The proportion of H influenzae isolates remained fairly constant at 30%-60% (depending on the year) during the decade reported. Pneumococcal isolates comprised less than 20% of the total in 2015 and 2016. In the samples obtained for this study, 45% of the H influenzae isolates produced beta-lactamase, as did 100% of the M catarrhalis isolates.

The investigators concluded that the microbiology of AOM changed during the pneumococcal conjugate vaccine era. However, compared with data from 30 years earlier, the risk factors for developing AOM were fairly similar, including a family history of AOM and attendance at daycare.


These data hold few surprises for pediatric clinicians. The risk factors for AOM are already well described. What was most interesting was the significant change in bacteriology—more than 50% of the isolates produced beta-lactamase. That finding supports the study's management approach of routinely using beta-lactamase-stable antibiotics for first-line treatment in a child who has been fully vaccinated against pneumococcus.

That doesn't mean that every child with AOM should be treated the same way, because local resistance patterns matter much more in treatment decisions. However, remaining cognizant of the high proportion of beta-lactamase-producing bacteria that are probably present in the middle ears of any fully immunized child is important, especially if first-line therapy appears to be failing in the child.


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