title: Non-tuberculous mycobacteria in children with cystic fibrosis: isolation, prevalence, and predictors.
abstract: BACKGROUND
  Screening for non-tuberculous mycobacteria (NTM) is recommended for adults with cystic fibrosis (CF). The relevance of this organism in North American pediatric CF patients is unclear as there is limited NTM prevalence data for children. We aimed to determine the prevalence of NTM in children with CF from a single expectorated sputum and identify clinical predictors of NTM isolation. Additionally, we compared two different sputum decontamination methods before mycobacterial culture.
  
  
  METHODS
  From March to November 2004, all sputum-producing patients aged 6-18 years attending the CF clinic at the Hospital for Sick Children in Toronto, Canada, were screened for NTM. Sputum samples were processed by both a single (N-acetyl-l-cysteine + NaOH) and double (N-acetyl-l-cysteine + NaOH + oxalic Acid) decontamination method. Using our CF clinic database and patient charts we analyzed differences in FEV(1), age, sex, pancreatic sufficiency, body mass index, bacterial colonization, and antibiotic use between NTM positive and negative patients.
  
  
  RESULTS
  Of 98 study patients, 6 (6.1%) were positive for NTM, 2 with Mycobacterium abscessus, and 4 with Mycobacterium avium complex. One patient with M. abscessus had clinically significant lung disease requiring treatment. We found no predictors of NTM isolation. The double decontamination method allowed detection of only half (3/6) of the positive NTM cultures.
  
  
  CONCLUSIONS
  As the NTM prevalence rate in children with CF is within the range previously reported in adults and there are no reliable clinical predictors for isolation, annual sputum screening is needed to identify NTM in children. Further research is needed to determine the best sputum decontamination method for NTM culture in pediatric patients.
authors.affiliation: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Dhenuka K
authors.initials: DK
authors.lastname: Radhakrishnan
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Yau
authors.forename: Mary
authors.initials: M
authors.lastname: Corey
authors.forename: Susan
authors.initials: S
authors.lastname: Richardson
authors.forename: Pamela
authors.initials: P
authors.lastname: Chedore
authors.forename: Frances
authors.initials: F
authors.lastname: Jamieson
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Dell
mesh_terms: D000293:Adolescent; D001431:Bacteriological Techniques / Q000379:methods; D002648:Child; D003550:Cystic Fibrosis / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D015269:Mycobacterium avium Complex / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000453:epidemiology*; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D013048:Specimen Handling / Q000379:methods; D013183:Sputum / Q000382:microbiology