Burkholderia cenocepacia and Burkholderia multivorans: influence on survival in cystic fibrosis

INTRODUCTION

Burkholderia cepacia infection has been associated with a poor prognosis for patients with cystic fibrosis (CF). It is now recognised that organisms classified as B cepacia comprise a number of distinct genomic species each known as a genomovar of the B cepacia complex (BCC). The outcome of infection for CF patients with individual genomovars is unknown. The clinical outcome of infection with the two most commonly isolated genomovars (B cenocepacia and B multivorans) was studied at a specialist CF centre between 1982 and 2003.

METHODS

The numbers of patients who progressed from initial to chronic infection were assessed. Control groups were created by matching patients with chronic BCC infection by percentage forced expiratory volume in 1 second with patients with Pseudomonas aeruginosa infection. Outcome measures were survival time, deaths from "cepacia syndrome", rate of decline in spirometry and body mass index (BMI), and treatment requirements.

RESULTS

Forty nine patients had an initial infection with either B multivorans (n = 16) or B cenocepacia (n = 33); 8/16 and 31/33, respectively, developed chronic infection (p<0.001). Deaths from "cepacia syndrome" occurred in both BCC groups. Patients with B cenocepacia infection had a shorter survival than patients with P aeruginosa infection (p = 0.01). There was no difference in survival between CF patients infected with B multivorans and P aeruginosa. There were no observed differences in changes in spirometry and BMI or treatment requirements between the BCC groups and respective controls.

CONCLUSION

In CF, the genomovar status of BCC may influence both the likelihood of progression from initial to chronic infection and the overall survival of the patients.