Negative pressure tympanograms in children less than 2 years of age--different bacterial findings in otitis media by tympanometric results.

OBJECTIVE: The interpretation of negative pressure tympanograms as indicators of the presence of middle ear fluid has been ambiguous. Our purpose was to assess the occurrence and implications of negative pressure tympanograms and to study their association with bacterial pathogens in otitis media. METHODS: Altogether 329 infants were enrolled at a well-baby clinic for the Finnish Otitis Media Cohort Study, a longitudinal prospective cohort study. The children were closely followed in a special study clinic from 2 to 24 months of age for respiratory diseases, especially acute otitis media. Children were examined at the study clinic with tympanometry and pneumatic otoscopy whenever visiting the study clinic for respiratory disease. Myringotomy with aspiration was performed if middle ear fluid was suspected in otoscopy. Occurrence of middle ear fluid in ears with negative pressure tympanograms (less than -100 daPa) was assessed. Nested case control design matched by visit type (acute or follow-up visit) and month of visit was used for analysis of association of bacterial pathogens and tympanometric results. RESULTS: Middle ear fluid was encountered in 15% of ears with negative tympanometric peak pressure, a lower proportion than described previously. In otitis media with a negative tympanometric peak pressure, 71% of bacterial cultures remained negative for the main pathogens, compared to 36% in matched controls (P<0.001). Especially Streptococcus pneumoniae but also Haemophilus influenzae were rarely found in samples from negative pressure ears. Moraxella catarrhalis was equally often found. CONCLUSIONS: Negative pressure tympanogram is a poor indicator for the presence of middle ear fluid. Furthermore, if otitis media is diagnosed with negative tympanometric peak pressure negative middle ear bacterial culture for the main pathogens is highly probable. Expectant follow-up might be more appropriate than routine antibiotic treatment.

Natural development of antibodies to pneumococcal capsular polysaccharides depends on the serotype: association with pneumococcal carriage and acute otitis media in young children.

To study the natural development of antibodies to pneumococcal capsular polysaccharides of types 1, 6B, 11A, 14, 19F, and 23F and its association with pneumococcal carriage and acute otitis media (AOM), 329 children were followed-up prospectively during their first 2 years of life. Nasopharyngeal carriage was determined by cultures of nasopharyngeal swab samples, and etiology of AOM was determined by cultures of middle ear fluid. Antibodies were measured in serum samples collected at 6, 12, 18, and 24 months by EIA. Antibodies increased modestly but significantly with age. Contact with serotypes 11A and 14 was associated with increased antibody concentration as early as age 6 months. Children with contact with serotypes 6B, 19F, and 23F had antibody levels similar to those in children without contact. Antibodies increased modestly, even in children without known contact with Streptococcus pneumoniae and in children with contact with heterologous serotypes. Antibody concentrations were equal after carriage or AOM.

Pneumococcal carriage and otitis media induce salivary antibodies to pneumococcal surface adhesin a, pneumolysin, and pneumococcal surface protein a in children.

Local antibodies probably contribute to defense against Streptococcus pneumoniae. This study examined whether pneumococcal carriage and acute otitis media (AOM) induce mucosal antibodies to potential vaccine candidates pneumococcal surface adhesin A (PsaA), pneumolysin (Ply), and pneumococcal surface protein A (PspA). IgA to all 3 proteins was detected by EIA in saliva of 329 children at ages 6, 12, 18, and 24 months and of 17 adults. A higher proportion of IgA-positive samples and higher antibody concentrations were seen in children with pneumococci-positive cultures of nasopharyngeal samples or middle ear fluid than in children with all cultures negative for pneumococci. The strong correlation between IgA and the presence of the secretory component suggests that the IgA was secretory. The findings indicate that pneumococcal carriage and AOM induce local production of anti-PsaA, anti-Ply, and anti-PspA antibodies early in life.