Risk factors for extreme-drug resistant Pseudomonas aeruginosa infections in patients with hematologic malignancies.
BACKGROUND
Extreme-drug resistant Pseudomonas aeruginosa (XDRPa) infection has emerged in our hematologic unit and is associated with increased mortality. Treatment options are limited, and infection prevention is currently the best option. We aimed to identify the risk factors for XDRPa infection in patients with hematologic malignancies to facilitate institution of stringent infection control measures.


METHODS
This was a retrospective matched case-control study (26 cases and 53 controls). XDRPa was detected using pulsed-field gel electrophoresis. Data were analyzed by conditional logistic regression and conditional multivariate logistic regression using Stata MP10.


RESULTS
Seventy-nine patients (49 males and 30 females; median age, 47 years; range, 16-79 years) were evaluated between December 2006 and December 2008. Independent predictors were use of carbapenem (odds ratio [OR], 10.63; 95% confidence interval [CI], 1.88-59.94; P < .01), Foley catheter insertion (OR, 11.24; 95% CI, 1.075-117.62; P = .04), and bone marrow aspiration (OR, 16.41; 95% CI, 1.57-171.73; P = .02). PFGE revealed 4 patterns. These XDRPa infections were borderline susceptible or resistant to polymyxin B and resistant to all other classes of antibiotics. The infection-attributed mortality of XDRPa was 53%. The median duration of hospitalization was 41 days (range, 19-83 days) in cases after XDRPa isolation and 28 days (range, 5-97 days) in controls.


CONCLUSIONS
The independent predictors for XDRPa infection were carbapenem use during the current admission, Foley catheter insertion, and bone marrow aspiration. More stringent infection control measures should be applied for patients with these predictors.
Department of Pharmacy, Singapore General Hospital, Singapore.
Yin-Xin
YX
Liew
Thuan-Tong
TT
Tan
Winnie
W
Lee
Jern-Lin
JL
Ng
De-Qing
DQ
Chia
Gee-Chuan
GC
Wong
Andrea L
AL
Kwa
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016022:Case-Control Studies; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D019337:Hematologic Neoplasms / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
D000900:Anti-Bacterial Agents