264. Utility of a Commercial Polymerase Chain Reaction Assay for Detection of Asymptomatic Carriers of Toxigenic Clostridium difficile in Two Veterans Affairs Long-Term Care Facilities
Session: Poster Abstract Session: Diagnostic Microbiology; Novel Molecular Methods
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C

Title:  Utility of a Commercial Polymerase Chain Reaction Assay for Detection of Asymptomatic Carriers of Toxigenic Clostridium difficile in Long-Term Care Facilities   

Curtis J. Donskey; Venkata C.K. Sunkesula ; Annette L. Jencson; Nimalie D. Stone; Carolyn V. Gould ; L. Clifford McDonald ; Matthew Samore; Jeanmarie Mayer; Susan M. Pacheco; Susan Sambol; Laurica Petrella; Deborah Terry; Dale N. Gerding

Background:   Asymptomatic carriers of Clostridium difficile may play a role in transmission of C. difficile in hospitals and long-term care facilities (LTCFs).  However, there are currently no simple and effective methods to rapidly identify carriers, particularly those at high risk for shedding of spores. 

Methods:   We evaluated the utility of a commercial polymerase chain reaction (PCR) assay (Xpert C. difficile, Cepheid) of perirectal swab specimens for detection of asymptomatic carriers of toxigenic C. difficile in 2 Department of Veterans Affairs LTCFs. Swabs were used to collect perirectal, skin (groin, chest/abdomen) and environmental cultures performed using selective agar; concurrent perirectal swabs were tested by PCR.  Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of perirectal PCR was calculated for detection of carriers and those carriers at increased risk for transmission (i.e., skin and /or environmental shedding).     

  Results:   Of 208 sets of specimens obtained from 143 subjects, 25 (12%) were positive for toxigenic C. difficile by perirectal culture, and 14 of 25 (56%) had positive skin and/or environmental cultures. For detection of carriers, sensitivity, specificity, PPV, and NPV of perirectal PCR were 68%, 100%, 100%, and 96%, respectively. For detection of carriers with positive skin and/or environmental shedding, sensitivity, specificity, PPV, and NPV of perirectal PCR were 93%, 98%, 76%, and 99%, respectively. Proportion of carriers with positive skin/environmental cultures or positive perirectal PCR results increased as number of colonies cultured per swab increased (Figure).        

 

Conclusion:   Commercial PCR assay of perirectal swab specimens could provide a sensitive and efficient means to identify subset of asymptomatic carriers of C. difficile at high risk for shedding of spores. 

 

 

 

 

Curtis Donskey, MD1, Venkata C.K. Sunkesula, M.D., M.S2,3, Annette Jencson, BSMT(ASCP)SM, CIC2, Nimalie Stone, MD, MS4, Carolyn Gould, MD5, Clifford Mcdonald, MD6, Matthew Samore, MD7, Jeanmarie Mayer, MD7, Susan M. Pacheco, MD8,9, Susan Sambol10, Laurica A. Petrella, BS8, Deborah Terry8 and Dale Gerding, MD, FIDSA11, (1)Infectious Diseases, Case Western Reserve University, Cleveland, OH, (2)Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, (3)Case Western Reserve University, Cleveland, OH, (4)Division Of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (5)Centers for Disease Control and Prevention, Atlanta, GA, (6)Centers for Disease Control, Atlanta, GA, (7)University of Utah School of Medicine, Salt Lake City, UT, (8)Edward Hines, Jr. Veterans Affairs Hospital, Hines, IL, (9)Loyola University Chicago, Maywood, IL, (10)Hines VA Hospital, Hines, IL, (11)Edward Hines, Jr. VA Hospital, Hines, IL

Disclosures:

C. Donskey, None

V. C. K. Sunkesula, None

A. Jencson, None

N. Stone, None

C. Gould, None

C. Mcdonald, None

M. Samore, None

J. Mayer, None

S. M. Pacheco, CDC: Grant Investigator, Research grant

S. Sambol, None

L. A. Petrella, None

D. Terry, None

D. Gerding, None

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