Long-term clinical outcomes of 'Prairie Epidemic Strain'Pseudomonas aeruginosainfection in adults with cystic fibrosis.
EpidemicPseudomonas aeruginosa(PA) plays an important role in cystic fibrosis (CF) lung disease. A novel strain, the 'Prairie Epidemic Strain' (PES), has been identified in up to 30% of patients in Prairie-based Canadian CF centres.



To determine the incidence, prevalence and long-term clinical impact of PES infection.



A cohort of adults with CF was followed from 1980 to 2014 where bacteria isolated from clinical encounters were prospectively collected. Strain typing was performed using pulse-field gel electrophoresis and multilocus sequence typing. Patients were divided into one of four cohorts: no PA, transient PA, chronic PA with unique strains and chronic PES. Proportional Cox hazard and linear mixed models were used to assess for CF-associated respiratory death or transplantation, and rates of %FEV1and body mass index (BMI) decline.



274 patients (51.7% male) were analysed: 44--no PA, 29--transient PA, 137--unique PA, 64--PES. A total of 92 patients (33.6%) died or underwent lung transplantation (2423.0 patient-years). PES infection was associated with greater risk of respiratory death or lung transplant compared with the no PA group (aHR, 3.94 (95% CI 1.18 to 13.1); p=0.03) and unique PA group (aHR, 1.75 (95% CI 1.05 to 2.92) p=0.03). Rate of lung function decline (%FEV1predicted) was greatest in the PES group (1.73%/year (95% CI 1.63% to 1.82%); p<0.001). BMI improved over time but at an attenuated rate in the PES group (p=0.001).



Infection with PES was associated with increased patient morbidity through three decades and manifested in an increased risk of respiratory death and/or lung transplantation.
Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Ranjani
R
Somayaji
Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
John C
JC
Lam
Departments of Medicine, and Biochemistry and Biomedical Sciences, The Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada.
Michael G
MG
Surette
Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada.
Barbara
B
Waddell
Departments of Medicine, and Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada.
Harvey R
HR
Rabin
Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Christopher D
CD
Sibley
Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada.
Swathi
S
Purighalla
Departments of Medicine, and Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada.
Michael D
MD
Parkins
D000328:Adult; D002170:Canada / Q000453:epidemiology; D003550:Cystic Fibrosis / Q000382:microbiology* / Q000628:therapy; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D015995:Prevalence; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000628:therapy; D011550:Pseudomonas aeruginosa / Q000145:classification*
Bacterial Infection; Clinical Epidemiology; Cystic Fibrosis; Respiratory Infection