691 Changing Epidemiology of Candidemia in Inpatient and Outpatient Populations: Preliminary Results of an Active, Population-Based Laboratory Surveillance in the United States- 2008-2009

Saturday, March 20, 2010: 3:15 PM
Regency VI-VII (Hyatt Regency Atlanta)
Angela M. Ahlquist, MPH , Centers for Disease Control, & Atlanta Research and Education Foundation, Atlanta, GA
Lee H. Harrison, MD , University of Pittsburgh, Pittsburgh, PA
Monica M. Farley, MD , Emory University, & Atlanta VA Medical Center, Atlanta, GA
Rosemary Hollick, MSc , Johns Hopkins University, Baltimore, MD
Wendy Baughman , Atlanta VA Medical Center, Atlanta, GA
Betsy Siegel , Emory University, Atlanta, GA
Sandra Muhanuka, RN, MPH , Johns Hopkins University, Baltimore, MD
Shawn R. Lockhart, PhD , Centers for Disease Control, Atlanta, GA
Benjamin J. Park, MD , Centers for Disease Control, Atlanta, GA
Tom Chiller, MD, MPHTM , Centers for Disease Control, Atlanta, GA
Background: Candida species are the fourth most common cause of hospital-associated bloodstream infections in the United States, although outpatient disease has been increasing.  Population-based surveillance conducted in Atlanta (1992-1993) and Baltimore (1998-2000) reported incidence rates of 7.9 and 19.4 per 100,000 population, respectively, of hospital-associated candidemia. 
Objective: To evaluate the changes in epidemiology of hospital-associated candidemia (HAC) and non-HAC.
Methods: Incident episodes of candidemia were identified through active, population-based surveillance in the metropolitan Atlanta (ATL) area (8 counties, population 3.8 million) and in Baltimore (BTM) City and County (population 1.4 million).  Demographic and clinical data were collected for all catchment-area residents with positive blood cultures for Candida spp.  To compare to prior surveillance, persons whose first positive blood culture was drawn >48 hours for BTM, and >24 hours for ATL after hospital admission were defined as HAC.  Factors associated with HAC were compared to non-HAC by chi-squared analysis.
Results: Between June 1, 2008 and November 1, 2009, we detected 819 cases of candidemia in ATL residents and 559 in BTM residents.  75% of cases in ATL and 61% in BTM were HAC, yielding incidence rates of 10.8 and 19.5 per 100,000 population, respectively.  Incidence of HAC increased by 36% in ATL and 0% in BTM.  Incidence rates of non-HAC increased in both locations, from 1.7 to 3.6 per 100,000 (118% increase) in ATL, and from 4.6 to 12.5 per 100,000 (174% increase) in BTM.  There were no significant differences between HAC and non-HAC in age, gender, diabetes, and previous liver diagnoses.  HAC was associated with a greater proportion of cases having prior surgery (58% vs 26%, p<0.05), having a C. albicans isolate (41% vs 25%, p<0.05), and a higher case fatality (33% vs. 16%, p<0.05).   C. glabrata was associated with non-HAC (35% non-HAC vs 27% HAC).
Conclusions: While incidence rates of hospital-associated candidemia increased slightly, rates of community-onset candidemia rose substantially.  Reasons for these changes in epidemiology are unclear.  There could be important differences between these two populations, and these changes deserve further study.