Otitis media is a middle ear infection that is most common in infants and young children, especially those between the ages of 6 months and 3 years. By the age of one year, most children will have had one or more middle ear infections. Although a middle ear infection can occur at any age, it's much less common in older children and adults. Ear infections do not spread from person to person and they most commonly occur with a cold. Antibiotics are often used to treat ear infections, but in certain circumstances, a doctor may suggest waiting for 2 to 3 days before starting antibiotics.