Asymptomatic Carriers Are a Potential Source for Transmission of Epidemic and Nonepidemic Clostridium difficile Strains among Long-Term Care Facility Residents

Abstract

Background. Asymptomatic fecal carriage of Clostridium difficile is common in patients staying in health care facilities, but the importance of asymptomatic carriers with regard to disease transmission is unclear.Methods. We prospectively examined the prevalence of asymptomatic carriage of epidemic North American pulsed-field gel electrophoresis type 1 and nonepidemic toxigenic C. difficile strains among long-term care patients in the context of an outbreak of C. difficile-associated disease and evaluated the frequency of skin and environmental contamination. Molecular typing was performed by pulsed-field gel electrophoresis. Logistic regression was used to assess factors associated with asymptomatic carriage, and a sensitive and specific prediction rule was developed to identify high-risk patients.Results. Thirty-five (51%) of 68 asymptomatic patients were carriers of toxigenic C. difficile, and 13 (37%) of these patients carried epidemic strains. Compared with noncarriers, asymptomatic carriers had higher percentages of skin (61% vs. 19%;) and environmental contamination (59% vs. 24%; ). Eighty-seven percent P p .001 P p .004 of isolates found in skin samples and 58% of isolates found in environmental samples were identical to concurrent isolates found in stool samples. Spores on the skin of asymptomatic patients were easily transferred to investigators' hands. Previous C. difficile-associated disease ( ) and previous antibiotic use ( ) were associated P ! .001 P p .017 with asymptomatic carriage, and the combination of these 2 variables was predictive of asymptomatic carriage (sensitivity, 77%; specificity, 58%; positive predictive value, 66%; negative predictive value, 70%).Conclusions. Our findings suggest that asymptomatic carriers of epidemic and nonepidemic C. difficile strains have the potential to contribute significantly to disease transmission in long-term care facilities. Clinical factors, such as previous C. difficile-associated disease and recent antibiotic use, may be predictive of asymptomatic carriage.

Guidelines for Diagnosis, Treatment, and Prevention of Clostridium difficile Infections

“…Among the elderly, carriage rates may be higher, especially in those in LTCFs. In one study of an epidemic in a LTCF, 51 % of asymptomatic carriers had toxigenic C. diffi cile ( 203 ), indicating that LTCF may be a reservoir for cases of CDI.…”

Clostridium difficile Infection Among Veterans Health Administration Patients

“…8 We used this washout period to minimize misclassification caused by carrying forward the ICD-9-CM diagnosis code for CDI during subsequent non-CDI clinical encounters.…”

Clostridium difficile infection in elderly nursing home residents

“…A reduced variability in the isolates from residential care facilities for elderly people was reported between different countries, with PCR ribotype 027 remaining the dominant type in nursing homes regardless of their location [10,17,20]. In an investigation of a large outbreak of C. difficile PCR-ribotype 027 infections in France from 2008 to 2009, elderly patients over 80 years old were found to be the main population affected.…”

“…Contaminated areas of the environment such as floors, electronic thermometers and even the air can contribute towards C. difficile transmission in healthcare settings [4,29]. In patient rooms, the most commonly contaminated areas have been identified as bedside tables, bedrails and toilet floors [17,26,27].…”