title: Species-Specific Risk Factors, Treatment Decisions, and Clinical Outcomes for Laboratory Isolates of Less Common Nontuberculous Mycobacteria in Washington State.
abstract: BACKGROUND
  Nontuberculous mycobacteria (NTM) are a diverse group of environmental organisms that infrequently cause human disease. Understanding of the epidemiologic and clinical characteristics associated with NTM disease is needed to refine diagnostic and treatment strategies, particularly among the less commonly isolated species.
  
  
  OBJECTIVE
  To improve knowledge of geographic variance of NTM species, to correlate detailed clinical information with isolation of specific NTM, and to examine the decision to treat and outcomes for specific NTM.
  
  
  METHODS
  Mycobacterial cultures submitted to the University of Washington mycobacterial laboratory from 1998 to 2011 were examined. We report isolation frequency and demographic information from all samples with clinical variables. We also examined treatment decisions and outcomes in a subset of patients with Mycobacterium abscessus complex, Mycobacterium chelonae, Mycobacterium fortuitum, Mycobacterium gordonae, Mycobacterium kansasii, Mycobacterium lentiflavum, Mycobacterium porcinum, and Mycobacterium xenopi.
  
  
  RESULTS
  Cultures of NTM were available from 3,470 patients, 937 of whom had clinical data available. When we compared patients born within or outside Washington State, we found that the mycobacterial species frequency varied. Among 168 patients with one of the studied environmental mycobacteria, 72% had major comorbid conditions. Bronchiectasis was common among patients with pulmonary isolation of any NTM, including those with nonpathogenic M. gordonae. Although mortality was high (37%), few deaths were directly attributable to mycobacterial infection. Among 56 patients who met American Thoracic Society criteria for NTM lung disease, 22 were treated, and 19 of those had M. abscessus complex and M. kansasii. The treatment regimens used tended to follow published guidelines.
  
  
  CONCLUSIONS
  Isolation of NTM varied by geographic region of origin and location within Washington State. Several clinical risk factors were specific to individual species. Comorbid conditions were common in patients with and without mycobacterial disease. Among patients with one of the studied organisms, there was a high mortality rate more frequently related to comorbid conditions than to mycobacterial disease.
authors.affiliation: 1 Department of Medicine, School of Medicine and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Ford
authors.affiliation: 1 Department of Medicine, School of Medicine and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: David J
authors.initials: DJ
authors.lastname: Horne
authors.affiliation: 1 Department of Medicine, School of Medicine and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: Javeed A
authors.initials: JA
authors.lastname: Shah
authors.affiliation: 3 Department of Laboratory Medicine, University of Washington, Seattle, Washington; and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: Carolyn K
authors.initials: CK
authors.lastname: Wallis
authors.affiliation: 1 Department of Medicine, School of Medicine and.|3 Department of Laboratory Medicine, University of Washington, Seattle, Washington; and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: Ferric C
authors.initials: FC
authors.lastname: Fang
authors.affiliation: 1 Department of Medicine, School of Medicine and.|2 Harborview Medical Center, Seattle, Washington.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Hawn
mesh_terms: D006801:Humans; D009161:Mycobacterium / Q000302:isolation & purification; D009165:Mycobacterium Infections, Nontuberculous / Q000628:therapy*; D009170:Nontuberculous Mycobacteria; D012307:Risk Factors; D013045:Species Specificity; D014861:Washington
keywords: Mycobacterium chelonae; Mycobacterium epidemiology; Mycobacterium pathogenicity; Mycobacterium xenopi; atypical mycobacteria