CHICAGO - Many epidemiological factors affect the incidence and prevalence of otitis media (OM).
"There can be big differences in the rates of detection of otitis media based on the instruments used to make the diagnosis. The age, race and ethnicity of the child influence incidence and prevalence, as do season of the year and exam frequency," said G. Scott Giebink, MD, at the annual meeting of the American Academy of Pediatrics held here.
The incidence of OM has increased dramatically during the past 25 years. The 2.5-fold increase during this time far exceeds population growth in the United States. Most of this increase has been in children younger than 2 years. "We believe that much of this rapid growth is due to children and infants being in out-of-home day care," he said.
While the incidence rates of OM have gone up, so have the rates of complications and the emergence of chronic otitis media with effusion (OME). "Of great implication is the fact that this disease has its onset early in life with tremendous implications and challenges for vaccine prophylaxis, particularly the recurrent form of otitis media. The type of prophylactic maneuvers probably need to be different for children with recurrent disease," he added.
---Encourage parents to
place their infants in a supine position to help prevent OM. Other
interventions parents can take are breast-feeding, using smaller day care
situations and not smoking around the child.
A few prenatal and perinatal factors have been identified as risk factors for acute and recurrent OM and chronic OME. Children with very low birthweight or who were born very preterm have higher rates of OM. "Approximately five years ago, we demonstrated that children who were born with low cord blood pneumococcal antibody concentrations against the most prevalent types of pneumococci had significantly earlier onset of otitis media. We've actually just initiated a maternal vaccine trial to try to boost these antibody levels, reasoning that we may be able to delay the onset of otitis," he explained.
No associations between otitis and prenatal diet or use of drugs, alcohol or medication have been established. Additionally, it is not associated with maternal illness in the third trimester.
However, there clearly is a genetic influence. "Two studies have shown a genetic influence in the neighborhood of 60% to 75%," Giebink said.
Boys are more likely to develop otitis media than girls. Additionally, there is a racial/ethnic influence on the frequency of OM. "The problem with socioeconomic factors as epidemiologic risk factors is that they are all intermixed. Crowding is associated with poor nutrition, poor hygiene, poor treatment compliance and delay in seeking medical attention. It is difficult to sort these factors out in a particular clinical study and decide if one or several are the factors that are influencing the outcome of that study," he added.
Breast-feeding seems to have a protective effect on OM. However, once a baby has been breast-fed for three months, there does not seem to be an increased protective effect with increased duration of breast-feeding. It has not been established whether the feeding position or the breast milk itself offers the protective effects.
While breast-feeding lowers the incidence rates of OM, parental smoking has been found to increase the incidence 1.5-fold.
The biggest risk factor, however, is attending day care. "Telling parents about the role of day care and explaining the germ theory really helps them understand the pathogenesis of otitis," Giebink said.
As the prevalence of multidrug-resistant pneumococci goes up, so does the prevalence of serious disease. "In many cases, we have to use intravenous vancomycin to treat these infections. This causes us to use more antibiotics, which leads to emerging resistance. It's not so much overuse of antibiotics for OM that causes the problem; far more, it's the overuse of antibiotics for children with upper respiratory infection, cough and sore throat," he said.
According to Giebink, it is important for physicians to encourage breast-feeding and supine sleeping, while discouraging parental smoking. "Small day care size obviously has a positive impact on rates of otitis. Additionally, a sibling history of recurrent otitis media is a big risk factor for a newborn. Supine sleep position is probably a negative risk factor. Promoting supine sleeping significantly reduced rates of recurrent otitis media in an ongoing study of otitis epidemiology and intervention in Great Britain," he explained.
For more information:
- Giebink S. Section on otolaryngology/bronchoesophagology and SENTAC. Presented at the annual meeting of the American Academy of Pediatrics. Oct. 28-Nov. 1, 2000. Chicago.
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