A 17-Year Nationwide Study of Burkholderia cepacia Complex (Bcc) Blood Stream Infections (BSI) Among Patients in the Veterans Health Administration (VHA)

Background: Bcc are a multidrug resistant group of at least 20 closely related species and a recognized cause of respiratory disease in patients with cystic fibrosis (CF) and immunocompromised adults, but BSIs are uncommon. We investigated the clinical characteristics, resistance patterns and treatment outcomes of Bcc BSI among VHA patients.

Methods: All cases of BSI with Bcc at the VHA facilities nationwide between 1999 and 2015 were reviewed. Factors associated with 90-day mortality were identified in a multivariate logistic regression (MVLR) analysis.

Results: 248 unique cases were found in a 17-year period (Table 1). Overall, < 20% of cases were treated with TMP/SMX, 28% of tested isolates were not susceptible to ceftazidime, and previous antibiotic use was significantly associated with both ceftazidime resistance and 90-day mortality. In a MVLR model predicting 90-day mortality, the Charlson Comorbidity Index (CCI) and combination antibiotic therapy were associated with significantly higher mortality [OR=1.2, 95% CI (1.1-1.3); OR=2.9, 95% CI (1.4-6.0)]. Healthcare acquisition, relative to hospital-acquired infection, and ID consultation appeared protective [OR=0.2, 95% CI (0.1-0.7), (OR=0.4, 95% CI (0.2-0.8)].

Conclusion: In the VHA, Bcc BSIs occurred in elderly, chronically ill patients in whom we observed high rates of mortality (36% at 90 days). This is the largest study of Bcc BSIs to date and describes the clinical and microbiological behavior of Bcc in non-CF patients. It also identifies knowledge gaps in the treatment of Bcc with a majority of patients not receiving the drug of choice (TMP/SMX); and reveals unexpectedly high level resistance to the second-line agent ceftazidime.

Table 1

	Survived (n=159)	Died (n=89)	p-value
Age - mean (sd)	65.16 (12.50)	72.10 (10.74)	<0.001
Male	155 (97.5)	87 (97.8)	1
CCI - mean (sd)	6.41 (2.63)	7.54 (2.63)	0.001
PBS - mean (sd)	1.27 (1.59)	4.17 (3.52)	<0.001
Source			0.043
CVC	70 (44.0)	31 (34.8)
Pneumonia	27 (17.0)	22 (24.7)
Other	26 (15.6)	7 (7.8)
Unknown	36 (22.6)	29 (32.6)
Acquisition			<0.001
CAI	19 (11.9)	4 (4.5)
HCAI	82 (51.6)	73 (82.0)
HAI	58 (36.5)	12 (13.5)
Prior antibiotic	118 (74.2)	82 (92.1)	0.001
ID consultation	96 (60.4)	42 (47.2)	0.061
Combination therapy	38 (23.9)	36 (40.4)	0.01

Data in no. (%) unless specified

PBS Pitt Bacteremia Score; CVC Central Venous Catheter; CAI Community Acquired Infection; HAI Hospital Acquired; HCAI Healthcare Associated