title: Use of nasopharyngeal culture to determine appropriateness of antibiotic therapy in acute bacterial rhinosinusitis.
abstract: BACKGROUND
  Rhinosinusitis is one of the top 5 diagnoses for which an antibiotic is prescribed, often without a clear bacterial etiology. This study evaluated whether nasopharyngeal culture and gram stain could serve as a surrogate for endoscopically obtained middle meatal cultures in directing appropriate therapy for acute bacterial rhinosinusitis (ABRS). This study also investigated the utility of a rapid sinus test screen in differentiating bacterial from nonbacterial rhinosinusitis.
  
  
  METHODS
  Thirty-one adult patients met inclusion criteria for ABRS. Samples were obtained from both the middle meatus and nasopharynx for Gram stain and culture. Nasal mucous samples were tested with a rapid sinus test strip measuring pH, levels of protein, nitrites, and leukocyte esterase.
  
  
  RESULTS
  Sixty-one percent (61%) of nasopharyngeal and 48% of middle meatal samples grew pathogenic bacteria. The concordance rate was 84% between the 2 sites (p = 0.0006). The following pathogenic organisms were detected: Moraxella catarrhalis, Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus. For nasopharyngeal samples, reliance on Gram stain alone exhibited a sensitivity of 31% and specificity of 100% and, similarly, for middle meatus samples, 47% and 93%, respectively. The rapid sinus test revealed a sensitivity of 83% and specificity of 7%.
  
  
  CONCLUSIONS
  Nasopharyngeal and middle meatal cultures exhibited high concordance for pathogenic bacteria. Gram stain exhibited moderate sensitivity and excellent specificity. Nasopharyngeal cultures could provide a viable method, especially in a primary care setting, for determining the appropriateness of antibiotic therapy. The rapid sinus test's lack of specificity precluded its utility in the differentiation between bacterial and nonbacterial rhinosinusitis.
authors.affiliation: Division of Sinonasal Disorders and Allergy, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA. lees6@upmc.edu
authors.forename: Stella
authors.initials: S
authors.lastname: Lee
authors.forename: Kristin
authors.initials: K
authors.lastname: Woodbury
authors.forename: Berrylin J
authors.initials: BJ
authors.lastname: Ferguson
mesh_terms: D000208:Acute Disease; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D002478:Cells, Cultured; D006801:Humans; D009305:Nasopharynx / Q000187:drug effects* / Q000382:microbiology / Q000473:pathology; D010256:Paranasal Sinuses / Q000187:drug effects* / Q000382:microbiology / Q000473:pathology; D061251:Primary Cell Culture; D012220:Rhinitis / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D012680:Sensitivity and Specificity; D012852:Sinusitis / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology
chemical_list: D000900:Anti-Bacterial Agents