Microbiology of otitis media in Costa Rican children, 1999 through 2001.
BACKGROUND
Because of the increasing number of resistant middle ear pathogens and the impact of the new conjugate Streptococcus pneumoniae vaccine, an active surveillance of the microbiology and susceptibility pattern of middle ear pathogens is required.


OBJECTIVE
To study the microbiology and susceptibility pattern of middle ear pathogens obtained from Costa Rican children with acute otitis media (AOM), recurrent otitis media (ROM) and therapeutic failure otitis media (FOM).


METHODS
Between 1999 and 2001 middle ear fluid (MEF) was collected from 276 Costa Rican patients. S. pneumoniae serotyping and pulsed field gel electrophoresis analysis was done on available strains.


RESULTS
Among the total study population, 102 were AOM patients, 98 were ROM patients and 76 were FOM patients. Overall S. pneumoniae (88 strains) was the most common pathogen isolated followed by Haemophilus influenzae (41 strains) and Streptococcus pyogenes (10 strains). H. influenzae was the most common agent in FOM patients (P = 0.015). Beta-lactamase production was observed in 3 of 41 (7%) H. influenzae strains and 3 of 3 (100%) Moraxella catarrhalis strains. Penicillin-nonsusceptible S. pneumoniae strains were more common in FOM (64%) and ROM (63%) patients than in AOM (42%) patients (P = 0.05). S. pneumoniae serotype 19F was the most prevalent serotype, mainly within one distinct clone.


CONCLUSIONS
Overall S. pneumoniae serotype 19F was the most common isolate from the middle ear fluid of Costa Rican children. Beta-lactamase-negative H. influenzae was the most prevalent in the subpopulation of patients with FOM. S. pyogenes was the third most common isolate and M. catarrhalis was uncommon.
Arguedas
Adriano
A
Instituto de Atención Pediátrica, San José, Costa Rica. aarguedas@iped.net
Dagan
Ron
R
Soley
Carolina
C
Loaiza
Cecilia
C
Knudsen
Katherine
K
Porat
Nurith
N
Pérez
Alexandra
A
Brilla
Eduardo
E
Herrera
Marco Luis
ML
D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003364:Costa Rica / Q000453:epidemiology; D004352:Drug Resistance, Microbial; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D010034:Otitis Media with Effusion / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D000900:Anti-Bacterial Agents