title: Acute effects of viral respiratory tract infections on sputum bacterial density during CF pulmonary exacerbations.
abstract: BACKGROUND
  Airway proliferation of Pseudomonas aeruginosa bacteria is thought to trigger CF exacerbations and may be affected by the presence of viral infections.
  
  
  METHODS
  A 2-year prospective study was conducted on 35 adults with CF. P. aeruginosa sputum density was analyzed during stable, exacerbation and post exacerbation assessments. Upon exacerbation, samples were sent for PCR detection of respiratory viruses and the sputum density of P. aeruginosa in patients with a viral infection versus those without was compared.
  
  
  RESULTS
  Twenty-two patients experienced 30 exacerbations during the study period; 50% were associated with a viral infection. There was no change in sputum density of P. aeruginosa from the stable to exacerbation state when measured by quantitative culture or by PCR. Virus-associated exacerbations did not result in significant increases in P. aeruginosa sputum density compared to non-viral exacerbations.
  
  
  CONCLUSIONS
  Sputum density of P. aeruginosa was not increased at the time of CF exacerbation and was not influenced by the presence of viral infection.
authors.affiliation: Department of Medicine, University of Ottawa, 501 Smyth Road, Box 206, Ottawa K1H 8L6, Canada. Electronic address: mchin@toh.on.ca.
authors.forename: Melanie
authors.initials: M
authors.lastname: Chin
authors.affiliation: Department of Medicine, University of Ottawa, 501 Smyth Road, Box 206, Ottawa K1H 8L6, Canada. Electronic address: mdezoysa@toh.on.ca.
authors.forename: Maya
authors.initials: M
authors.lastname: De Zoysa
authors.affiliation: Children's Hospital of Eastern Ontario, University of Ottawa, 401 Smyth Road, Ottawa K1H 8L1, Canada. Electronic address: slinger@cheo.on.ca.
authors.forename: Robert
authors.initials: R
authors.lastname: Slinger
authors.affiliation: Ottawa Hospital Research Institute, University of Ottawa, 501 Smyth Road, K1H 8L6 Ottawa, Canada. Electronic address: emgaudet@rogers.com.
authors.forename: Ena
authors.initials: E
authors.lastname: Gaudet
authors.affiliation: Ottawa Hospital Research Institute, University of Ottawa, 501 Smyth Road, K1H 8L6 Ottawa, Canada. Electronic address: kvandemheen@toh.on.ca.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Vandemheen
authors.affiliation: Children's Hospital of Eastern Ontario, University of Ottawa, 401 Smyth Road, Ottawa K1H 8L1, Canada. Electronic address: chan@cheo.on.ca.
authors.forename: Francis
authors.initials: F
authors.lastname: Chan
authors.affiliation: Children's Hospital of Eastern Ontario, University of Ottawa, 401 Smyth Road, Ottawa K1H 8L1, Canada. Electronic address: lhyde43@hotmail.com.
authors.forename: Lucie
authors.initials: L
authors.lastname: Hyde
authors.affiliation: Department of Medicine, University of Ottawa, 501 Smyth Road, Box 206, Ottawa K1H 8L6, Canada. Electronic address: tmah@uottawa.ca.
authors.forename: Thien-Fah
authors.initials: TF
authors.lastname: Mah
authors.affiliation: Children's Hospital of Eastern Ontario, University of Ottawa, 401 Smyth Road, Ottawa K1H 8L1, Canada. Electronic address: wferris@rogers.com.
authors.forename: Wendy
authors.initials: W
authors.lastname: Ferris
authors.affiliation: Ottawa Hospital Research Institute, University of Ottawa, 501 Smyth Road, K1H 8L6 Ottawa, Canada. Electronic address: rmallick@ohri.ca.
authors.forename: Ranjeeta
authors.initials: R
authors.lastname: Mallick
authors.affiliation: Ottawa Hospital Research Institute, University of Ottawa, 501 Smyth Road, K1H 8L6 Ottawa, Canada. Electronic address: saaron@ohri.ca.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Aaron
mesh_terms: D000293:Adolescent; D000328:Adult; D058491:Bacterial Load; D003550:Cystic Fibrosis / Q000150:complications / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000150:complications / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012141:Respiratory Tract Infections / Q000150:complications / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology*; D014777:Virus Diseases / Q000150:complications / Q000382:microbiology*; D055815:Young Adult
keywords: CF exacerbation; Cystic fibrosis; Pseudomonas aeruginosa; Viral infection