Infrequent Skin Contamination with Clostridium difficile Spores Among Oncology Patients on Units with a High Incidence of C. difficile Colonization

Background: Numerous studies have demonstrated that patients with Clostridium difficile infection (CDI) or asymptomatic carriage of C. difficile may shed spores into the environment. However, relatively little is known about the frequency of contamination of patients’ skin with spores, particularly in high-risk settings such as oncology units. We examined the frequency of C. difficile skin contamination in 3 units with a high burden of C. difficile colitis.

Methods: In a single day, we performed a point prevalence surveillance study of patients admitted to the 3 hematology and oncology units. Pre-moistened sterile rayon applicators were used to swab approximately 10x10 cm of the abdomen and groin areas. Swabs were processed using broth enrichment cultures in C. difficile selective media. No patients refused culturing. Additionally, stool cultures in these 3 units are obtained on admission and weekly thereafter in order to determine their C. difficile carrier status.

Results: A total of 39 patients underwent skin cultures. Surveillance stool cultures were positive for C. difficile colonization in four out of the 33 (12%) patients before the skin cultures were obtained. Of the four patients with positive stool cultures, two had a diagnosis of CDI in the prior month and one developed CDI during the following week. Nine out of 39 patients (23%) had previously been diagnosed or were diagnosed on admission with C. difficile colitis. Two (5%) of these patients were being treated for CDI at the time skin cultures were collected. Out of 39 patients, none of the skin cultures were positive for C. difficile. A positive control was performed concomitantly which indicated that the media was adequate.

Conclusion: All patients surveyed in a high endemic unit for C. difficile were found to be negative for C. difficile on skin cultures despite 12% of patients demonstrating evidence of C. difficile colonization from stool cultures. The transmission dynamics of the organism may differ depending on the healthcare setting. Further research is needed to better understand the pathophysiology of C. difficile especially in the hematology and oncology population.