Why acute otitis media prevalence is decreasing
Fewer infants today experience acute ear infections than 2 or 3 decades ago, according to researchers from the University of Texas Medical Branch (UTMB) at Galveston, who attribute the drop to improved rates of breastfeeding and vaccination, and lower smoking rates.
The study, published in Pediatrics, involved 367 infants with a total of 887 upper respiratory infections (URI) and 180 episodes of acute otitis media (AOM). They found that in comparison to 20 to 30 years ago, rates of AOM have fallen in 3-month-olds from 18% to 6%; from 39% to 23% in 6-month-olds; and from 62% to 46% in 1-year-olds.
Tasnee Chonmaitree, MD, professor of pediatrics and pathology at UTMB and co-author of both this study and American Academy of Pediatrics’ (AAP’s) 2013 guidance on AOM management, says reducing AOM prevalence is not an easy task.
“Because otitis media (OM) is a complex and multifactorial disease, reducing its incidence requires many factors. Combination of new bacterial pnemococcal conjugate vaccines (PCVs), routine use of influenza vaccines, increased breastfeeding rate, decreased smoking rates are among the contributing factors,” she says. “Our study identified the 3 most important risk factors for acute otitis media: nasopharyngeal bacterial colonization, frequent common cold, and lack of breastfeeding.”
The UTMB report found that ear infections occurred more often in children with more frequent respiratory infections, with AOM occurring in children with 4.7 URI episodes per year, compared to the 2.3 URI infections that occurred in children with no AOM. Additionally, pathogenic bacterial colonization was “significantly higher” in infants with AOM, according to the report.
All but 2 of the cases of AOM developed within 28 days of an URI, according to the report, with AOM typically occurring 5 days after the onset of an URI.
The researchers also noted that while almost half of the infants involved in the study experienced AOM by age 1 year, receiving pneumococcal conjugate and influenza vaccinations; being breastfed; and living with nonsmokers are powerful preventive measures.
Bacterial cultures collected from the study participants also revealed useful information, with colonization rates with 3 pathogenic bacteria (Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae) increasing with age—most frequently overall in infants with AOM.