title: Two-Phase Hospital-Associated Outbreak of Mycobacterium abscessus: Investigation and Mitigation.
abstract: BACKGROUND
  Nontuberculous mycobacteria (NTM) commonly colonize municipal water supplies and cause healthcare-associated outbreaks. We investigated a biphasic outbreak of Mycobacterium abscessus at a tertiary care hospital.
  
  
  METHODS
  Case patients had recent hospital exposure and laboratory-confirmed colonization or infection with M. abscessus from January 2013 through December 2015. We conducted a multidisciplinary epidemiologic, field, and laboratory investigation.
  
  
  RESULTS
  The incidence rate of M. abscessus increased from 0.7 cases per 10000 patient-days during the baseline period (January 2013-July 2013) to 3.0 cases per 10000 patient-days during phase 1 of the outbreak (August 2013-May 2014) (incidence rate ratio, 4.6 [95% confidence interval, 2.3-8.8]; P < .001). Thirty-six of 71 (51%) phase 1 cases were lung transplant patients with positive respiratory cultures. We eliminated tap water exposure to the aerodigestive tract among high-risk patients, and the incidence rate decreased to baseline. Twelve of 24 (50%) phase 2 (December 2014-June 2015) cases occurred in cardiac surgery patients with invasive infections. Phase 2 resolved after we implemented an intensified disinfection protocol and used sterile water for heater-cooler units of cardiopulmonary bypass machines. Molecular fingerprinting of clinical isolates identified 2 clonal strains of M. abscessus; 1 clone was isolated from water sources at a new hospital addition. We made several water engineering interventions to improve water flow and increase disinfectant levels.
  
  
  CONCLUSIONS
  We investigated and mitigated a 2-phase clonal outbreak of M. abscessus linked to hospital tap water. Healthcare facilities with endemic NTM should consider similar tap water avoidance and engineering strategies to decrease risk of NTM infection.
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.|Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Baker
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.|Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Lewis
authors.affiliation: Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.|Duke University Clinical Microbiology Laboratory, Durham, North Carolina.
authors.forename: Barbara D
authors.initials: BD
authors.lastname: Alexander
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.|Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Luke F
authors.initials: LF
authors.lastname: Chen
authors.affiliation: Duke University Clinical Microbiology Laboratory, Durham, North Carolina.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wallace
authors.affiliation: Duke University Clinical Microbiology Laboratory, Durham, North Carolina.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Brown-Elliott
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Isaacs
authors.affiliation: Division of Trauma and Critical Care, Duke University Hospital, Durham, North Carolina.
authors.forename: Lisa C
authors.initials: LC
authors.lastname: Pickett
authors.affiliation: Division of Cardiology, Duke University Hospital, Durham, North Carolina.
authors.forename: Chetan B
authors.initials: CB
authors.lastname: Patel
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Hospital, Durham, North Carolina.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Smith
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Hospital, Durham, North Carolina.
authors.forename: John M
authors.initials: JM
authors.lastname: Reynolds
authors.affiliation: Duke University Hospital, Durham, North Carolina.
authors.forename: Jill
authors.initials: J
authors.lastname: Engel
authors.affiliation: Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Cameron R
authors.initials: CR
authors.lastname: Wolfe
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Hospital, Durham, North Carolina.
authors.forename: Carmelo A
authors.initials: CA
authors.lastname: Milano
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Hospital, Durham, North Carolina.
authors.forename: Jacob N
authors.initials: JN
authors.lastname: Schroder
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Hospital, Durham, North Carolina.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Davis
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Duke University Hospital, Durham, North Carolina.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Hartwig
authors.affiliation: Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Stout
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.
authors.forename: Nancy
authors.initials: N
authors.lastname: Strittholt
authors.affiliation: Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Eileen K
authors.initials: EK
authors.lastname: Maziarz
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.
authors.forename: Jennifer Horan
authors.initials: JH
authors.lastname: Saullo
authors.affiliation: Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Hazen
authors.affiliation: Perfusion Services, Duke University Hospital, Durham, North Carolina.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Walczak
authors.affiliation: Mycobacteria/Nocardia Research Laboratory, Department of Microbiology, University of Texas Health Science Center, Tyler.
authors.forename: Ravikiran
authors.initials: R
authors.lastname: Vasireddy
authors.affiliation: Mycobacteria/Nocardia Research Laboratory, Department of Microbiology, University of Texas Health Science Center, Tyler.
authors.forename: Sruthi
authors.initials: S
authors.lastname: Vasireddy
authors.affiliation: Duke University Clinical Microbiology Laboratory, Durham, North Carolina.
authors.forename: Celeste M
authors.initials: CM
authors.lastname: McKnight
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.|Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Deverick J
authors.initials: DJ
authors.lastname: Anderson
authors.affiliation: Duke Program for Infection Prevention and Healthcare Epidemiology, Duke University Hospital, Durham, North Carolina.|Division of Infectious Diseases, Duke University Hospital, Durham, North Carolina.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sexton
mesh_terms: D000368:Aged; D003428:Cross Infection; D004196:Disease Outbreaks; D005260:Female; D005798:Genes, Bacterial; D006761:Hospitals; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology*; D000073358:Mycobacterium abscessus / Q000145:classification* / Q000235:genetics*; D012307:Risk Factors
keywords: Mycobacterium abscessus; hospital outbreak; hospital water safety; infection control; nontuberculous mycobacteria