Clinical Outcomes Associated with Achromobacter Species Infection in Patients with Cystic Fibrosis

Abstract

Rationale: Achromobacter species are increasingly identified in individuals with cystic fibrosis (CF), but the clinical outcomes in these patients remain poorly understood.

Objectives: We aimed to determine the association of Achromobacter infection on clinical outcomes in pediatric and adult patients with CF.

Methods: A cohort study of pediatric and adult patients with CF was conducted from 1997 to 2014 in Toronto, Ontario, Canada. Achromobacter spp. infection was categorized as no history of infection, intermittent infection, and chronic infection (two or more positive cultures in the preceding 12 months). Cox models were used to estimate risk of death or transplantation. Mixed-effects models were used to assess odds of pulmonary exacerbations and effect on lung function (FEV₁%) by Achromobacter spp.

Results: A total of 1,103 patients were followed-up over the course of 18 years; 88 patients (7.3%) had one or more culture for Achromobacter species. Chronic Achromobacter infection was associated with a greater risk of death or transplantation compared with in patients with no history of infection (adjusted hazard ratio, 2.03; 95% confidence interval, 1.05-3.95; P = 0.036). Pulmonary exacerbations were more common in patients with chronic infection, but after adjusting for confounding factors, the effect was no longer significant. The chronic group had lower FEV₁%, but it did not worsen after developing chronic infection.

Conclusions: Patients with CF and chronic Achromobacter infection are at increased risk of death or transplantation.

Keywords: achromobacter; cystic fibrosis; exacerbations; mortality; transplantation.