Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis

Luke D Knibbs, Graham R Johnson, Timothy J Kidd, Joyce Cheney, Keith Grimwood, Jacqueline A Kattenbelt, Peter K O'Rourke, Kay A Ramsay, Peter D Sly, Claire E Wainwright, Michelle E Wood, Lidia Morawska, Scott C Bell

Research output: Contribution to journalArticle

47 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)740-745
Number of pages6
JournalThorax
Volume69
Issue number8
DOIs
Publication statusPublished - Aug 2014

Fingerprint

Aerosols
Cough
Cystic Fibrosis
Pseudomonas aeruginosa
Sputum
Patients' Rooms
Respiratory Muscles
Infectious Disease Transmission
Bacterial Load
Muscle Strength
Microbiology
Ventilation
Air
Equipment and Supplies
Lung

Keywords

  • Adolescent
  • Adult
  • Aerosols
  • Case-Control Studies
  • Cough
  • Cystic Fibrosis
  • Female
  • Humans
  • Inhalation Exposure
  • Male
  • Pseudomonas Infections
  • Pseudomonas aeruginosa
  • Respiratory Function Tests
  • Sputum

Cite this

Knibbs, L. D., Johnson, G. R., Kidd, T. J., Cheney, J., Grimwood, K., Kattenbelt, J. A., ... Bell, S. C. (2014). Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis. Thorax, 69(8), 740-745. https://doi.org/10.1136/thoraxjnl-2014-205213
Knibbs, Luke D ; Johnson, Graham R ; Kidd, Timothy J ; Cheney, Joyce ; Grimwood, Keith ; Kattenbelt, Jacqueline A ; O'Rourke, Peter K ; Ramsay, Kay A ; Sly, Peter D ; Wainwright, Claire E ; Wood, Michelle E ; Morawska, Lidia ; Bell, Scott C. / Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis. In: Thorax. 2014 ; Vol. 69, No. 8. pp. 740-745.
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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.",
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Knibbs, LD, Johnson, GR, Kidd, TJ, Cheney, J, Grimwood, K, Kattenbelt, JA, O'Rourke, PK, Ramsay, KA, Sly, PD, Wainwright, CE, Wood, ME, Morawska, L & Bell, SC 2014, 'Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis', Thorax, vol. 69, no. 8, pp. 740-745. https://doi.org/10.1136/thoraxjnl-2014-205213

Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis. / Knibbs, Luke D; Johnson, Graham R; Kidd, Timothy J; Cheney, Joyce; Grimwood, Keith; Kattenbelt, Jacqueline A; O'Rourke, Peter K; Ramsay, Kay A; Sly, Peter D; Wainwright, Claire E; Wood, Michelle E; Morawska, Lidia; Bell, Scott C.

In: Thorax, Vol. 69, No. 8, 08.2014, p. 740-745.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis

AU - Knibbs, Luke D

AU - Johnson, Graham R

AU - Kidd, Timothy J

AU - Cheney, Joyce

AU - Grimwood, Keith

AU - Kattenbelt, Jacqueline A

AU - O'Rourke, Peter K

AU - Ramsay, Kay A

AU - Sly, Peter D

AU - Wainwright, Claire E

AU - Wood, Michelle E

AU - Morawska, Lidia

AU - Bell, Scott C

PY - 2014/8

Y1 - 2014/8

N2 - 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.

AB - 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.

KW - Adolescent

KW - Adult

KW - Aerosols

KW - Case-Control Studies

KW - Cough

KW - Cystic Fibrosis

KW - Female

KW - Humans

KW - Inhalation Exposure

KW - Male

KW - Pseudomonas Infections

KW - Pseudomonas aeruginosa

KW - Respiratory Function Tests

KW - Sputum

U2 - 10.1136/thoraxjnl-2014-205213

DO - 10.1136/thoraxjnl-2014-205213

M3 - Article

C2 - 24743559

VL - 69

SP - 740

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JO - Thorax

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SN - 0040-6376

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Knibbs LD, Johnson GR, Kidd TJ, Cheney J, Grimwood K, Kattenbelt JA et al. Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis. Thorax. 2014 Aug;69(8):740-745. https://doi.org/10.1136/thoraxjnl-2014-205213