Distribution of otitis media among four Indian populations in Arizona.

More than 75 percent of the cases of acute suppurative otitis media (ASOM) among Indian children observed from May 1974 through March 1979 were experienced by preschool children. About 60 percent of the children observed during the first year of life had one or more attacks of ASOM, and 34 percent had two or more. Among those who had ASOM before their first birthday, 75 percent of the attacks occurred between 3 and 9 months of age. About 73 percent of the initial attacks were recorded during the first year of life among children observed from 3 to 5 years; almost 90 percent occurred before the second birthday. Approximately 75 percent of the second attacks occurred within 4 months of the first. More than 70 percent of the initial attacks before age 1 were followed by 1 or more subsequent attacks during the next 12 months. When the initial attack occurred during the second year of life, subsequent attacks were experienced by less than half as many children. Children at high risk of serious ear disease, including hearing loss, are characterized by having an attack of ASOM before their first birthday followed by a second attack within 4 months of the first. Efforts to control and prevent ASOM should selectively be directed toward this group.