Risk factors for fluconazole resistance in patients with Candida glabrata bloodstream infection: potential impact of control group selection on characterizing the association between previous fluconazole use and fluconazole resistance.
BACKGROUND
Although Candida glabrata is an emerging infection, risk factors for fluconazole resistance in patients with C glabrata bloodstram infection (BSI) have not been well elucidated.


METHODS
A case-control study was conducted to evaluate the primary risk factor of interest, previous fluconazole use, adjusting for demographics, comorbidities, time at risk, and antimicrobial exposure and assessing for effect modification. Secondary analyses were performed limiting the case group to C glabrata BSIs with a minimum inhibitory concentration (MIC) > or =64 microg/mL.


RESULTS
Previous fluconazole use was not a significant risk factor for fluconazole-resistant C glabrata BSI in primary analysis (adjusted odds ratio [aOR], 1.5; 95% confidence interval [CI], 0.7-3.2) but was borderline significant in secondary analysis (aOR, 3.2; 95% CI, 0.9-11.3). Increased time at risk was an independent risk factor in primary (aOR, 1.02; 95% CI, 1.002-1.04) and secondary analyses (aOR, 1.03; 95% CI, 1.004-1.06).


CONCLUSIONS
Increased time at risk was the only significant risk factor for fluconazole resistance. Future studies are needed to further evaluate the relationship between previous fluconazole use and fluconazole-resistant C glabrata BSI isolates with MIC > or =64 microg/mL.
Lee
Ingi
I
Division of Infectious Diseases, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. ingi.lee@uphs.upenn.edu
Zaoutis
Theoklis E
TE
Fishman
Neil O
NO
Morales
Knashawn H
KH
Nachamkin
Irving
I
Lautenbach
Ebbing
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000008:administration & dosage*; D041221:Candida glabrata / Q000187:drug effects* / Q000302:isolation & purification*; D002177:Candidiasis / Q000188:drug therapy* / Q000382:microbiology*; D016022:Case-Control Studies; D025141:Drug Resistance, Fungal; D005260:Female; D015725:Fluconazole / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012307:Risk Factors; D013997:Time Factors
D000935:Antifungal Agents; D015725:Fluconazole