title: Potential contribution by nontypable Haemophilus influenzae in protracted and recurrent acute otitis media.
abstract: BACKGROUND
  Characterization of acute otitis media (AOM) caused by nontypable Haemophilus influenzae (NTHi) is important, particularly in view of the efforts to develop vaccines against NTHi. To characterize NTHi AOM a large database of culture-positive AOM cases was analyzed.
  
  
  METHODS
  All culture-positive AOM episodes (NTHi, Streptococcus pneumoniae, Moraxella catarrhalis, and Streptococcus pyogenes) in children <5 years old from 1999 through 2006, processed in our center were included. One isolate was counted per episode (< or = 30 days). Demographic and clinical data were retrieved from charts or by telephone interviews. Multivariable regression analysis models were used.
  
  
  RESULTS
  Twelve thousand eight hundred twenty-three (8145 culture-positive) episodes were included. NTHi was recovered in 4928 episodes; S. pneumoniae in 4399 episodes, M. catarrhalis in 499, and S. pyogenes in 447 episodes. Independent risk factors for NTHi AOM (in culture-positive episodes) were: winter (odds ratio [OR]: 1.2, 95% confidence interval [CI]: 1.05-1.33, P = 0.006); bilateral AOM (OR: 1.26, 95% CI: 1.12-1.42, P < 0.001); >3 previous AOM episodes (OR: 1.27, 95% CI: 1.11-1.47, P = 0.001); and antibiotic consumption in previous month (OR: 1.3, 95% CI: 1.15-1.46, P < 0.001). ORs for these variables remained significant when the analysis was conducted on single-pathogen AOM only. For both NTHi and S. pneumoniae, risk factors for mixed episodes were older age and bilateral AOM.
  
  
  CONCLUSIONS
  NTHi AOM is characterized by higher occurrence in winter, bilaterality, recurrence, and previous antibiotic treatment compared with that caused by S. pneumoniae. These findings are in agreement with data associating NTHi with protracted or recurrent morbidity. The finding that S. pneumoniae and NTHi mixed episodes are more likely to occur in older children and in bilateral AOM suggests that interaction between these 2 pathogens contributes to chronicity or complexity of AOM.
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Galia
authors.initials: G
authors.lastname: Barkai
authors.forename: Eugene
authors.initials: E
authors.lastname: Leibovitz
authors.forename: Noga
authors.initials: N
authors.lastname: Givon-Lavi
authors.forename: Ron
authors.initials: R
authors.lastname: Dagan
mesh_terms: D000208:Acute Disease; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D004432:Ear, Middle / Q000382:microbiology; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D007557:Israel / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D001936:Moraxella catarrhalis; D045828:Moraxellaceae Infections / Q000453:epidemiology; D010033:Otitis Media / Q000453:epidemiology* / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000453:epidemiology; D012008:Recurrence; D012307:Risk Factors; D012621:Seasons; D013290:Streptococcal Infections / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D013297:Streptococcus pyogenes