title: The prevalence of potential pathogenic bacteria in nasopharyngeal samples from individuals with a respiratory tract infection and a sore throat--implications for the diagnosis of pharyngotonsillitis.
abstract: BACKGROUND
  Treatment failure in patients with pharyngotonsillitis after a traditional course of penicillin V is a common finding. Several factors have been proposed to explain the failure rate, but the presence of aetiological agents other than group A beta-haemolytic streptococci has attracted little attention.
  
  
  OBJECTIVE
  The aim of the present study was to investigate if a nasopharyngeal sample could suggest the aetiology of a sore throat in patients with a respiratory tract infection.
  
  
  METHODS
  The prevalence of potentially pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) in nasopharyngeal samples from 618 healthy individuals was compared with that from 108 patients with a respiratory tract infection and a sore throat.
  
  
  RESULTS
  The prevalence of H.influenzae was higher in patients with a sore throat than in healthy individuals of the same age. For the adult patients with a sore throat, the prevalence was 27.5% compared with 2.7% for the healthy carriers (P < 10(-7)). The corresponding figures for schoolchildren were 31.3% versus 6.1% (P = 0.004) and for pre-school children 37.8% versus 13.2% (P = 0.0003).
  
  
  CONCLUSIONS
  If H.influenzae is found in a nasopharyngeal sample from a patient with a respiratory tract infection and a sore throat, it might be the aetiological agent.
authors.affiliation: Department of Primary Health Care, Göteborg University, Sweden.
authors.forename: R K
authors.initials: RK
authors.lastname: Gunnarsson
authors.forename: S E
authors.initials: SE
authors.lastname: Holm
authors.forename: M
authors.initials: M
authors.lastname: Söderström
mesh_terms: D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology*; D006193:Haemophilus influenzae; D006801:Humans; D001936:Moraxella catarrhalis; D009305:Nasopharynx / Q000382:microbiology*; D016870:Neisseriaceae Infections / Q000453:epidemiology / Q000382:microbiology*; D010612:Pharyngitis / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013296:Streptococcus pneumoniae; D013548:Sweden / Q000453:epidemiology; D014069:Tonsillitis / Q000453:epidemiology / Q000382:microbiology*