Epidemiology of otitis media.

Although otitis media (OM) incidence and prevalence estimates from around the world vary widely, it is clear that OM is a very common childhood disease. It is especially prevalent in children younger than 2 years of age. Furthermore, the earlier the first episode of OM, the greater the risk of subsequent recurrent OM and chronic otitis media with effusion. In addition, a number of other host, agent, and environmental factors have been associated with increased risk of otitis media. Environmental factors that favor the transmission of upper respiratory pathogens increase the risk of OM, recurrent OM, and chronic OME with effusion. Several factors suggest a genetic role in OM susceptibility, which needs further exploration.