title: The efficacy of cough plates in the identification of bacterial pathogens in children with cystic fibrosis.
abstract: BACKGROUND
  Identification of bacterial pathogens is paramount for prompt and effective treatment of respiratory exacerbations in children with cystic fibrosis (CF). This can be a challenge in non-expectorating patients as reliability of cough swabs (CS) is poor. More recently, cough plates (CP) have been reported to give high yields in some series. The aim of the study was to ascertain their effectiveness compared to CS and to assess the impact of cough strength on efficacy of CP.
  
  
  METHODS
  Non-expectorating children with CF aged 3-16 years were recruited. Baseline data was recorded and peak cough flow measured. Specimens were obtained with CP and a cough swab in a randomised order and repeated at up to four clinic visits to obtain multiple measurements. Subjects completed a short questionnaire.
  
  
  RESULTS
  Number of subjects was 95, mean age 8.8±4.1 years, 45 males. Mean baseline % predicted FEV1 was 90.8±18. In total, 324 sets of specimens were collected. Pathogens were isolated in 18.2% of CS and 8% of CP. Agreement between the two specimens occurred in only 5.5% of cases. CP isolated pathogens on six occasions when the CS was negative while 40 CS were positive with a corresponding negative CP. Cough strength increased with age, and there was a trend towards older children isolating more pathogens on CP. However, this was not statistically significant. The majority of subjects preferred the CP.
  
  
  CONCLUSIONS
  CP are less effective than CS in identifying respiratory pathogens in children with CF.
authors.affiliation: Paediatric Respiratory Unit, Great North Children's Hospital, , Newcastle upon Tyne, UK.
authors.forename: N M
authors.initials: NM
authors.lastname: Byrne
authors.forename: C
authors.initials: C
authors.lastname: O'Brien
authors.forename: D A
authors.initials: DA
authors.lastname: Spencer
mesh_terms: D000293:Adolescent; D001419:Bacteria / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D003371:Cough / Q000382:microbiology*; D003550:Cystic Fibrosis / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D012141:Respiratory Tract Infections / Q000382:microbiology*; D013048:Specimen Handling / Q000295:instrumentation*; D013183:Sputum / Q000382:microbiology*
keywords: Cough plates; Cough swabs; Cystic Fibrosis