title: Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis.
abstract: BACKGROUND
  Person-to-person transmission of respiratory pathogens, including Pseudomonas aeruginosa, is a challenge facing many cystic fibrosis (CF) centres. Viable P aeruginosa are contained in aerosols produced during coughing, raising the possibility of airborne transmission.
  
  
  METHODS
  Using purpose-built equipment, we measured viable P aeruginosa in cough aerosols at 1, 2 and 4 m from the subject (distance) and after allowing aerosols to age for 5, 15 and 45 min in a slowly rotating drum to minimise gravitational settling and inertial impaction (duration). Aerosol particles were captured and sized employing an Anderson Impactor and cultured using conventional microbiology. Sputum was also cultured and lung function and respiratory muscle strength measured.
  
  
  RESULTS
  Nineteen patients with CF, mean age 25.8 (SD 9.2) years, chronically infected with P aeruginosa, and 10 healthy controls, 26.5 (8.7) years, participated. Viable P aeruginosa were detected in cough aerosols from all patients with CF, but not from controls; travelling 4 m in 17/18 (94%) and persisting for 45 min in 14/18 (78%) of the CF group. Marked inter-subject heterogeneity of P aeruginosa aerosol colony counts was seen and correlated strongly (r=0.73-0.90) with sputum bacterial loads. Modelling decay of viable P aeruginosa in a clinic room suggested that at the recommended ventilation rate of two air changes per hour almost 50 min were required for 90% to be removed after an infected patient left the room.
  
  
  CONCLUSIONS
  Viable P aeruginosa in cough aerosols travel further and last longer than recognised previously, providing additional evidence of airborne transmission between patients with CF.
authors.affiliation: International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia School of Population Health, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Luke D
authors.initials: LD
authors.lastname: Knibbs
authors.affiliation: International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Graham R
authors.initials: GR
authors.lastname: Johnson
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kidd
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia Queensland Children's Respiratory Centre, Royal Children's Hospital, Herston, Queensland, Australia.
authors.forename: Joyce
authors.initials: J
authors.lastname: Cheney
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Keith
authors.initials: K
authors.lastname: Grimwood
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Kattenbelt
authors.affiliation: QIMR/RBWH Statistics Unit, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia.
authors.forename: Peter K
authors.initials: PK
authors.lastname: O'Rourke
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Kay A
authors.initials: KA
authors.lastname: Ramsay
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Sly
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia Queensland Children's Respiratory Centre, Royal Children's Hospital, Herston, Queensland, Australia.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Wainwright
authors.affiliation: Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Wood
authors.affiliation: International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Lidia
authors.initials: L
authors.lastname: Morawska
authors.affiliation: Queensland Children's Medical Research Institute, The University of Queensland, Herston, Queensland, Australia Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Bell
mesh_terms: D000293:Adolescent; D000328:Adult; D000336:Aerosols; D016022:Case-Control Studies; D003371:Cough / Q000382:microbiology*; D003550:Cystic Fibrosis / Q000382:microbiology*; D005260:Female; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D011552:Pseudomonas Infections / Q000382:microbiology* / Q000635:transmission*; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012129:Respiratory Function Tests; D013183:Sputum / Q000382:microbiology
chemical_list: D000336:Aerosols
keywords: Bacterial Infection; Cystic Fibrosis; Infection Control; Respiratory Infection
references.citation: Emerg Infect Dis. 2006 Nov;12(11):1657-62
references.pmid: 17283614
references.citation: Lancet. 2013 May 4;381(9877):1551-60
references.pmid: 23541540
references.citation: Curr Opin Infect Dis. 2011 Aug;24(4):390-5
references.pmid: 21543979
references.citation: Am J Infect Control. 2011 Dec;39(10):866-72
references.pmid: 21658810
references.citation: JAMA. 2010 Nov 17;304(19):2145-53
references.pmid: 21081727
references.citation: Public Health Rep. 2008 Jan-Feb;123(1):52-60
references.pmid: 18348480
references.citation: J Infect Dis. 2012 Sep 15;206(6):902-6
references.pmid: 22807521
references.citation: Indoor Air. 2007 Feb;17(1):2-18
references.pmid: 17257148
references.citation: Thorax. 2003 Jun;58(6):525-7
references.pmid: 12775867
references.citation: Appl Microbiol. 1971 Feb;21(2):244-52
references.pmid: 5549701
references.citation: Chest. 2014 Apr;145(4):678-680
references.pmid: 24135971
references.citation: Am J Respir Crit Care Med. 2002 Oct 1;166(7):983-7
references.pmid: 12359658
references.citation: Eur Respir J. 2013 May;41(5):1091-100
references.pmid: 22878877
references.citation: J Pediatr. 2001 May;138(5):699-704
references.pmid: 11343046
references.citation: Chest. 2002 Aug;122(2):603-11
references.pmid: 12171839
references.citation: J Hosp Infect. 2005 Feb;59(2):102-7
references.pmid: 15620443
references.citation: Lancet. 2012 Dec 15;380(9859):2095-128
references.pmid: 23245604
references.citation: J Cyst Fibros. 2010 Jan;9(1):64-8
references.pmid: 19944655
references.citation: Pediatr Pulmonol. 2007 Jun;42(6):525-32
references.pmid: 17469153
references.citation: Am J Respir Crit Care Med. 2013 May 1;187(9):1007-15
references.pmid: 23306539
references.citation: Eur Respir J. 2005 Nov;26(5):948-68
references.pmid: 16264058
references.citation: MMWR Recomm Rep. 2005 Dec 30;54(RR-17):1-141
references.pmid: 16382216
references.citation: J Med Virol. 2013 Dec;85(12):2151-9
references.pmid: 23959825
references.citation: Eur Respir J. 2012 Jul;40(1):227-38
references.pmid: 22323572
references.citation: Infect Control Hosp Epidemiol. 2003 May;24(5 Suppl):S6-52
references.pmid: 12789902
references.citation: Am J Infect Control. 2007 Dec;35(10 Suppl 2):S65-164
references.pmid: 18068815
references.citation: BMC Microbiol. 2008 Jun 26;8:105
references.pmid: 18582388
references.citation: Lancet. 2009 May 30;373(9678):1891-904
references.pmid: 19403164
references.citation: Am J Infect Control. 2008 May;36(4):250-9
references.pmid: 18455045
references.citation: Thorax. 2009 Nov;64(11):926-31
references.pmid: 19574243
references.citation: Am J Respir Crit Care Med. 2005 May 1;171(9):1020-5
references.pmid: 15709051
references.citation: Chest. 2014 Apr;145(4):680-683
references.pmid: 24135999
references.citation: Am J Respir Crit Care Med. 2005 Feb 1;171(3):257-60
references.pmid: 15542795