Incidence of acute otitis media up to the age of 1 1/2 years in urban infants.

The object of this prospective cohort investigation of 1,642 infants was to study the incidence of acute otitis media (AOM) in urban children during the first 18 months of life. The monthly incidence of AOM was greatest at the age of 10 months, and the largest proportion of children with AOM was also found in this 10-month age group. Before the age of 18 months, 56.7% of the infants had had at least one episode of AOM, while 26.9% had had one or two episodes and 29.8% three or more. The corresponding figures before the age of 12 months were: 45.3%; 26.8%; 18.5%, and before the age of 9 months: 30.5%; 22.1%; 8.4%. The AOM incidence, particularly as regards recurrent AOM, was rather higher in boys than in girls.