With proper medical treatment, the bacteria causing the infection will be killed. As fluid and pus disappear from the middle ear, hearing improves. Acute otitis media is a common childhood ailment. Two out of three children under the age of 3 experience at least one episode of acute otitis media, especially children in child care or who live in a home with a smoker. Acute otitis media frequently occurs as an aftereffect of respiratory infections as the nasal membranes and eustachian tube become swollen and congested.
Viruses are an important cause of ear infections and often found along with bacterial infections.
Streptococcus pneumoniae , Hemophilus influenza , and Moraxella catarhalis are common bacterial offenders, with pneumococcus being the most common and the most likely to cause complications. Newer vaccines given in infancy for pneumococcus are aimed at the types of bacteria that cause ear infections. Sometimes a mixture of microorganisms may be found. Infants under 6 weeks of age may show a different group of bacteria in the middle ear. This may last for 3 to 6 weeks after the initial antibiotic therapy.