We studied the incidence of exudative otitis media in 488 patients followed up from birth. Forty-nine percent (240) of the patients had their initial episode of otitis media in the first year of life and only 12% (56) in the second year of life. Thereafter, the incidence decreased steadily. Patients having six or more episodes of otitis media before age 6 were termed "otitis prone." Fi f t y\ x=req-\ seven such patients were observed and this condition was found to be significantly related to the onset of otitis media in the firstyear of life and to the pneumococcal cause of the initial episode.

The antibody response in serum and middle ear fluid was studied in 40 children less than two years of age who had otitis media due to Haemophilus influenzae. Specific antibody in serum was determined by either a bacteriocidal test or an indirect fluorescent antibody test, and in the middle ear fluid by the latter test. For both assays the infecting bacterium of the patient was used. Half of the acute sera and three-fourths of the convalescent sera had antibody of at least one of the IgG, IgM, or IgA classes; IgG occurred most often. Fourteen patients had significant increases in specific antibody in the convalescent serum. Middle ear fluids from 22 to 29 patients had specific antibody. IgG and IgA antibodies occurred with equal frequency, but IgA antibody was found more often in middle ear fluids when IgA antibody was absent from serum. Thus it appears that infants with otitis media respond systemically and locally with specific antibody to H. influenzae.

Ampicillin and a fixed combination of erythromycin estolate-triple sulfonamide suspension proved equally effective in eradicating or ganisms and exudate in otitis media. Triple sulfonamide was not as effective as a number of other drugs tested for eliminating the pneu mococcus, and erythromycin estolate was not as effective as the fixed combination or ampicillin with Hemophilus influenzae.

Seventy percent of pneumococci isolated from the middle-ear cavity of infants and children with acute otitis media were of one of the seven serotypes 1, 3, 6, 14, 18, 19, or 23. The immunological response in the serum and middle-ear fluid from otitis media caused by one of these serotypes was studied in 61 children by using either indirect hemagglutination or indirect fluorescent antibody tests, or both. Twenty-six of the patients had pneumococcal antibody present in the acute serum and 28 had it in the convalescent serum by at least one method. Thirteen of the 49 middle-ear fluids examined had antibody by the indirect fluorescent antibody technique. Serum pneumococcal antibody was found to reside predominantly in the immunoglobulin G or immunoglobulin M classes, whereas pneumococcal antibody with middle-ear fluid was found to be distributed equally among all three classes. Approximately 25% of the patients (16 of 61) had a positive immune response to their infection as evidenced by increased levels of pneumococcal antibody in the convalescent serum. The percentage of patients responding immunologically increased with age: 12% of infants less than 12 months showed a significant response, whereas 48% of children over 24 months responded.

No abstract