title: Increasing Nocardia Incidence Associated with Bronchiectasis at a Tertiary Care Center.
abstract: BACKGROUND
  Nocardia is a genus of pathogens that most commonly afflict immunocompromised hosts but may be an emerging infection among persons with bronchiectasis.
  
  
  OBJECTIVE
  To examine the epidemiology and clinical presentation of adult patients with Nocardia and bronchiectasis relative to other patient groups.
  
  
  METHODS
  We examined a retrospectively assembled cohort of adults at Duke University Hospital in Durham, North Carolina with at least one positive culture from a bodily fluid or tissue specimen for Nocardia between January 1996 and December 2013. Denominator data for key populations (e.g., bronchiectasis, transplant) were obtained using International Classification of Diseases, Ninth Revision codes. In addition, we performed a case-control analysis to examine the relationship between inhaled corticosteroid use and Nocardia lung infection among otherwise immunocompetent patients with bronchiectasis.
  
  
  RESULTS
  We identified 183 patients with one or more cultures positive for Nocardia: 44 from 1996 to 2001, 64 from 2002 to 2007, and 75 from 2008 to 2013. Immune compromise was common (56%), particularly solid organ or hematopoietic cell transplant (30%). Infection usually was confined to the lungs (62%), followed by skin (10%), other sites (6%), brain (2%), and multiple sites (17%). Non-cystic fibrosis bronchiectasis was common among both immunocompetent (38%) and immunocompromised (10%) patients. Nocardia incidence in patients with bronchiectasis increased significantly over time, but there was no significant change in Nocardia incidence in hematopoietic cell or solid organ transplant recipients (our largest immunocompromised population). Among patients with bronchiectasis, Nocardia was positively but nonsignificantly associated with use of inhaled corticosteroids (odds ratio, 1.8; 95% confidence interval, 0.7-4.4).
  
  
  CONCLUSIONS
  The increasing incidence of Nocardia infections at our medical center appears to be driven by increased incidence in patients with bronchiectasis rather than increases in immunocompromised populations. It is unclear whether increased environmental exposures, microbiologic surveillance, or other factors account for the increased incidence of Nocardia in our patients with bronchiectasis.
authors.affiliation: 1 Department of Medicine.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Woodworth
authors.affiliation: 2 Division of Infectious Diseases and International Health, Department of Medicine.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Saullo
authors.affiliation: 3 Division of Hospital Medicine, Department of Internal Medicine, and.|4 Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Lantos
authors.affiliation: 2 Division of Infectious Diseases and International Health, Department of Medicine.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Cox
authors.affiliation: 2 Division of Infectious Diseases and International Health, Department of Medicine.
authors.forename: Jason E
authors.identifier: http://orcid.org/0000-0002-6698-8176
authors.initials: JE
authors.lastname: Stout
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001987:Bronchiectasis / Q000453:epidemiology* / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006801:Humans; D016867:Immunocompromised Host; D015994:Incidence; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009615:Nocardia / Q000302:isolation & purification*; D009617:Nocardia Infections / Q000453:epidemiology*; D009657:North Carolina / Q000453:epidemiology; D016377:Organ Transplantation / Q000009:adverse effects; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D013997:Time Factors; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones
keywords: Nocardia; bronchiectasis; epidemiology; immunocompromised host; opportunistic infections