Long-term clinical outcomes of 'Prairie Epidemic Strain' Pseudomonas aeruginosa infection in adults with cystic fibrosis.
RATIONALE
Epidemic Pseudomonas 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.


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


METHODS
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 %FEV1 and body mass index (BMI) decline.


RESULTS
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 (%FEV1 predicted) 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).


CONCLUSIONS
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.
['Somayaji|Ranjani|R|', 'Lam|John C|JC|', 'Surette|Michael G|MG|', 'Waddell|Barbara|B|', 'Rabin|Harvey R|HR|', 'Sibley|Christopher D|CD|', 'Purighalla|Swathi|S|', 'Parkins|Michael D|MD|']
D000328:Adult D002170:Canada D003550:Cystic Fibrosis 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 D011550:Pseudomonas aeruginosa
Cystic Fibrosis Bacterial Infection Clinical Epidemiology Respiratory Infection