title: Bacterial and viral interactions within the nasopharynx contribute to the risk of acute otitis media.
abstract: OBJECTIVE
  To understand relationships between microbes in pathogenesis of acute otitis media during respiratory tract infections, we compared nasopharyngeal bacteria and respiratory viruses in symptomatic children with and without AOM.
  
  
  METHODS
  We enrolled children (6-35 months) with acute symptoms suggestive of AOM and analyzed their nasopharyngeal samples for bacteria by culture and for 15 respiratory viruses by PCR. Non-AOM group had no abnormal otoscopic signs or only middle ear effusion, while AOM group showed middle ear effusion and acute inflammatory signs in pneumatic otoscopy along with acute symptoms.
  
  
  RESULTS
  Of 505 children, the non-AOM group included 187 and the AOM group 318. One or more bacterial AOM pathogen (Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis) was detected in 78% and 96% of the non-AOM and AOM group, respectively (P < .001). Colonization with S. pneumoniae and H. influenzae, each alone, increased risk of AOM (odds ratio (OR) 2.92; 95% confidence interval (CI), .91-9.38, and 5.13; 1.36-19.50, respectively) and co-colonization with M. catarrhalis further increased risk (OR 4.36; 1.46-12.97, and 9.00; 2.05-39.49, respectively). Respiratory viruses were detected in 90% and 87% of the non-AOM and AOM group, respectively. RSV was significantly associated with risk of AOM without colonization by bacterial AOM pathogens (OR 6.50; 1.21-34.85).
  
  
  CONCLUSIONS
  Co-colonization by M. catarrhalis seems to increase risk of AOM and RSV may contribute to AOM pathogenesis even without nasopharyngeal bacterial colonization.
authors.affiliation: Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland. aino.ruohola@utu.fi
authors.forename: Aino
authors.initials: A
authors.lastname: Ruohola
authors.forename: Melinda M
authors.initials: MM
authors.lastname: Pettigrew
authors.forename: Laura
authors.initials: L
authors.lastname: Lindholm
authors.forename: Jari
authors.initials: J
authors.lastname: Jalava
authors.forename: Kati S
authors.initials: KS
authors.lastname: Räisänen
authors.forename: Raija
authors.initials: R
authors.lastname: Vainionpää
authors.forename: Matti
authors.initials: M
authors.lastname: Waris
authors.forename: Paula A
authors.initials: PA
authors.lastname: Tähtinen
authors.forename: Miia K
authors.initials: MK
authors.lastname: Laine
authors.forename: Elina
authors.initials: E
authors.lastname: Lahti
authors.forename: Olli
authors.initials: O
authors.lastname: Ruuskanen
authors.forename: Pentti
authors.initials: P
authors.lastname: Huovinen
mesh_terms: D000208:Acute Disease; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D008297:Male; D056265:Microbial Interactions; D001936:Moraxella catarrhalis / Q000302:isolation & purification / Q000378:metabolism; D009305:Nasopharynx / Q000382:microbiology / Q000821:virology; D010033:Otitis Media / Q000382:microbiology / Q000503:physiopathology* / Q000821:virology; D016133:Polymerase Chain Reaction; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000821:virology; D012307:Risk Factors; D013296:Streptococcus pneumoniae / Q000302:isolation & purification / Q000378:metabolism; D014780:Viruses / Q000235:genetics / Q000378:metabolism*