Risk factors for Candida colonization and Co-colonization with multi-drug resistant organisms at admission

Danielle M. Schulte, Ajay Sethi, Ronald Gangnon, Megan Duster, Dennis G. Maki, Nasia Safdar

Candida species are major causes of healthcare-associated infections with colonization preceding infection. Understanding risk factors for colonization by Candida species is important in prevention. However, data on risk factors for colonization by Candida species alone or with other healthcare-associated pathogens is limited. From 2002 to 2006, 498 patients were enrolled into a prospective cohort study at our institution. Surveillance perirectal, nasal and skin swab samples were obtained upon enrollment. Samples were cultured for the presence of Candida species, Methicillin Resistant Staphylococcus aureus, Vancomycin Resistant Enterococcus, and Resistant Gram Negative organisms. Data on demographics, comorbidities, device use, and antibiotic use were also collected for each subject and analyzed using univariate and multivariate logistic regression. Factors associated with Candida colonization at admission in univariate analysis included ambulatory status, a history of Candida colonization and the use of antibiotics prior to enrollment. In multivariate analysis, ambulatory status (odds ratio; OR = 0.45, 95 % CI: 0.27-0.73) and fluroquinolone use (OR = 3.01, 95 % CI: 1.80-5.01) were associated with Candida colonization at admission. Factors predicting Candida co-colonization with one or more MDROs at admission in univariate analysis included, older age, malnutrition, days spent in an ICU in the 2 years prior to enrollment, a history of MRSA colonization, and using antibiotics prior to enrollment. In multivariate analysis malnutrition (OR = 3.97, 95 % CI: 1.80-8.78) a history of MRSA (OR = 5.51, 95 % CI: 1.89-16.04) and the use of macrolides (OR = 3.75, 95 % CI: 1.18-11.93) and other antibiotics (OR = 4.94, 95 % CI: 1.52-16.03) were associated with Candida co-colonization at admission. Antibiotic use was associated with an increased risk of colonization by Candida species alone and in conjunction with other multidrug-resistant organisms (MDROs). Antibiotic stewardship may be an important intervention for preventing colonization and subsequent infection by Candida and other MDROs.