Seasonal distribution of otitis media pathogens among Costa Rican children

Silvia Guevara, Carolina Soley, Adriano Arguedas, Nurith Porat, Ron Dagan

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


BACKGROUND: Otitis media is an important cause of pediatric consultation, and knowledge of yearly pathogen distribution might improve antimicrobial selection. OBJECTIVES: To determine the seasonal pathogen and antimicrobial resistance distribution among Costa Rican children with otitis media. METHODS: Between 1999 and 2004, 952 children with otitis media, aged 3-144 months who participated in various clinical trials, were analyzed. Data obtained from this period were compared against historical data collected between 1992 and 1997. RESULTS: Five hundred sixteen (52%) children had a baseline middle ear fluid pathogen isolated. The most common pathogens were Streptococcus pneumoniae 252 (49%), Haemophilus influenzae 190 (37%), S. pyogenes 38 (7%), and Moraxella catarrhalis 36 (7%). The overall proportion of H. influenzae (24-37%; P = 0.01) and the production of β-lactamase producing H. influenzae (2.6-7%; P = 0.02) increased from 1992-1997 to 1999-2004. There was a nonstatistically significant trend for a higher frequency of S. pneumoniae and H. influenzae isolates detected during the rainy season than during the dry season: S. pneumoniae 58% versus 42% but not significant (P = 0.1) and H. influenzae 68% versus 32% (P = 0.06), respectively. During the rainy season, penicillin-nonsusceptible S. pneumoniae was identified more frequently (38.5%) than during the dry season (18%) (P = 0.003; odds ratio: 2.94; 95% confidence interval: 1.4-6.45). Penicillin-nonsusceptible S. pneumoniae decreased from 46.5% (1999-2001) to 16% (2002-2003) and this was associated with a significant decline of a circulating 19F penicillin-resistant S. pneumoniae serotype (from 89% to 26%), respectively. CONCLUSIONS: S. pneumoniae and H. influenzae are the 2 most common pathogens producing otitis media in Costa Rican children. An increase in the number of H. influenzae and M. catarrhalis was observed in recent years. Penicillin-nonsusceptible S. pneumoniae isolates were more commonly observed during the rainy season, in which increased morbidity with respiratory pathogens is observed.

Original languageEnglish
Pages (from-to)12-16
Number of pages5
JournalPediatric Infectious Disease Journal
Issue number1
StatePublished - 1 Jan 2008


  • Haemophilus influenzae
  • Otitis media
  • Seasonality
  • Streptococcus pneumoniae

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Microbiology (medical)
  • Infectious Diseases


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