1415. Identification of Asymptomatic Clostridium difficile Colonization among Healthy Adults
Session: Poster Abstract Session: Clostridium difficile
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • 20130925IDSAPosterAG.pdf (182.4 kB)
  • Background: Clostridium difficile infection (CDI) has shown dramatic increase in incidence and morbidity during the last decade. Thirty percent of CDI is estimated to be community-acquired, but the sources of these infections are unclear. Previous studies conducted outside the United States (U.S.) suggest that 7-15% of healthy adults are colonized with C. difficile (CD). The aims of this study are to examine the prevalence, genotypic distribution, and duration of CD colonization and to identify risk factors associated with colonization among healthy adults in the U.S.

    Methods: Healthy adults were recruited via advertisements. Individuals who reported chronic diarrhea, recent hospitalization, history of CDI, or employment in a health care facility were excluded. Eligible participants provided epidemiologic data via written questionnaire and submitted a stool specimen. Subjects whose stool yielded CD were asked to submit additional specimens. Specimens were cultured for CD using direct plating and broth enrichment. CD isolates underwent tcdCgenotyping. Genotypic data were compared between study subjects and a historic sample of unique CDI patients from the same geographic region. Epidemiologic data were analyzed to identify characteristics associated with CD colonization.

    Results: Eighty-three (79%) of 109 subjects submitted specimens, 6 of whom (7.2%) were colonized with CD. Five subjects submitted additional specimens. Stool from 1 individual yielded CD on 2 successive occasions 1 month apart. The following tcdC genotypic distribution was observed among 7 isolates from colonized individuals: tcdC 3, (n=1) tcdC 5, (n=1) tcdC 14, (n=1) tcdC 20, (n=1) tcdC novel, (n=1) tcdC 19, (n=2 specimens, 1 individual). The 6 tcdC genotypes indentified among colonized individuals collectively account for 30% of infections among a historic cohort of 337 patients with CDI. Demographics, diet, health care facility exposure, antibiotic exposure, and exposure to persons with CDI were not significantly associated with CD colonization.

    Conclusion: The prevalence of CD colonization in this healthy cohort is concordant with estimates in non-U.S. populations. Colonized individuals may be important reservoirs for CDI. A larger sample size may be necessary to identify risk factors for CD colonization among healthy adults.

    Alison Galdys, MD, Scott Curry, Kathleen Shutt, MS and Lee Harrison, MD, Infectious Diseases, University of Pittsburgh, Pittsburgh, PA


    A. Galdys, None

    S. Curry, None

    K. Shutt, Merck: Investigator, Research grant

    L. Harrison, None

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