title: Effects of segregation on an epidemic Pseudomonas aeruginosa strain in a cystic fibrosis clinic.
abstract: The detection of a clonal Pseudomonas aeruginosa strain in 21% of children attending a cystic fibrosis clinic during 1999, which may have led to a worse prognosis, prompted strict infection control measures, including cohort segregation. We determined whether these strategies interrupted cross-infection within the clinic. Patients from 1999 were observed and a cross-sectional study of the 2002 clinic was performed. By 2002, the epidemic strain prevalence had decreased from 21 to 14% (p = 0.03), whereas the proportion of patients with nonepidemic P. aeruginosa strains was unchanged. The age- and sex-adjusted relative risk for epidemic strains among sputum producers in 2002 compared with 1999 was 0.64 (95% confidence interval, 0.47, 0.87; p = 0.004). Increased mortality or transfer to another clinic did not explain this reduction. Although children with epidemic strains may have had increased mortality (adjusted odds ratio, 2.0; 95% confidence interval, 0.6-6.8), they did not demonstrate greater morbidity than those with other P. aeruginosa isolates. Successful infection control measures provided additional indirect evidence for person-to-person transmission of an epidemic strain within the clinic. Further studies are needed to resolve whether cohort segregation completely eliminates cross-infection and if acquisition of epidemic isolates is associated with worse outcomes.
authors.affiliation: Department of Respiratory Medicine, Royal Children's Hospital, Parkville, Australia.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Griffiths
authors.forename: Kris
authors.initials: K
authors.lastname: Jamsen
authors.forename: John B
authors.initials: JB
authors.lastname: Carlin
authors.forename: Keith
authors.initials: K
authors.lastname: Grimwood
authors.forename: Rosemary
authors.initials: R
authors.lastname: Carzino
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Robinson
authors.forename: John
authors.initials: J
authors.lastname: Massie
authors.forename: David S
authors.initials: DS
authors.lastname: Armstrong
mesh_terms: D000293:Adolescent; D015373:Bacterial Typing Techniques; D002648:Child; D015331:Cohort Studies; D015897:Comorbidity; D003428:Cross Infection; D003550:Cystic Fibrosis / Q000453:epidemiology*; D004196:Disease Outbreaks / Q000517:prevention & control*; D005260:Female; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008297:Male; D015995:Prevalence; D011552:Pseudomonas Infections / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000302:isolation & purification; D013183:Sputum / Q000382:microbiology; D014774:Virulence