STREPTOCOCCUS-PNEUMONIAE COLONIZATION IN THE YOUNG-CHILD - ASSOCIATION WITH OTITIS-MEDIA AND RESISTANCE TO PENICILLIN

Objective: To determine the nasopharyngeal colonization rate of penici llin-susceptible and penicillin-resistant strains of Streptococcus pne umoniae in young children, and to assess its relationship with the inc idence of otitis media, Design: Observational study in 215 children yo unger than 6 years of age who received care in the Vanderbilt Vaccine Clinic from September 1, 1992, to August 31, 1993, Results: Of 842 nas opharyngeal cultures obtained, results for 44% of the cultures were po sitive for S, pneumoniae; 73% of the isolates were serotypes 6, 14, 19 , or 23. Younger children had significantly higher rates of pneumococc al colonization than older children, with a peak at 1 year of age, By microdilution susceptibility testing, 37% of the cultures with positiv e results were intermediately or highly resistant to penicillin, Signi ficantly more serotype 19 and 23 isolates were penicillin resistant th an organisms of other serotypes, Children younger than 2 years of age had a twofold higher percentage of resistant isolates than those older than 2 years of age, A significant association was noted between naso pharyngeal carriage of S. pneumoniae and acute otitis media (p = 0.000 2); however, the incidence of acute otitis media did not differ signif icantly between children colonized with penicillin-susceptible or peni cillin-resistant strains. Unresolved otitis media was diagnosed more o ften in children who were colonized with resistant organisms than in c hildren colonized with susceptible strains (p = 0.04), Conclusions: Th ere was a high rate of nasopharyngeal carriage of penicillin-resistant S. pneumoniae in this population of young children, Nasopharyngeal co lonization was associated with an increased incidence of acute otitis media, and penicillin resistance was associated with an increased inci dence of unresolved otitis media.