Background: Toxigenic C. difficile (CD) has been recovered food and may be a source of CD exposure in hospitalized patients. The objective of this study was to estimate the risk of colonization associated with the presence of CD in the food of hospitalized patients.
Methods: Subjects admitted to Barnes Jewish Hospital from May 2011 to July 2012 without diarrhea were recruited. Subjects placed samples of food from each meal into sterile specimen cups. Following homogenization, food was cultured for CD. A stochastic, discrete event model that simulated the flow of patients admitted to the hospital and predicted exposure to CD from food determined the number of new CD colonization events that occur from food (Figure 1). The baseline number of spores per contaminated meal was represented by a Poisson Log-normal distribution with mean 2 and standard deviation 0.8. Only patients exposed to antimicrobials were at risk for CD colonization, with a baseline 50% of patients on antimicrobials (range 30% to 70%). The likelihood of becoming colonized for people on antimicrobials was estimated from Villano, AAC, 2012, p5224-9. The probability of food contamination was determined by this study (baseline 0.002, range 0.0005 to 0.02). The number of estimated new colonizations per 1,000 admissions was determined.
Results: CD was cultured from 2/910 (0.2%) samples from the food of 2/148 patients (1.4%). The quantity of CD in the specimens was <10 spores. The number of meals consumed daily is shown in Table 1. In the baseline scenario (50% antimicrobial exposure, probability of contamination 0.002, simulated mean number spores = 10), the mean number of new colonizations from food was 0.55/1,000 admissions (range 0.28-0.78/1,000 admissions). If the prescribing rate were to vary from 30% to 70%, probability of spore contamination from 0.0005 to 0.02, and number of spores per meal from 0-33, 0-817, this would not significantly impact the predicted number of new colonizations (mean 0.54/1,000 admissions, range 0.23-0.99/1,000 admissions).
Conclusion: CD was infrequently cultured from the food of hospitalized patients. Ingestion of CD contaminated food in the hospital setting is not an important source of new CD colonizations.
Table 1. Number of Meals Consumed Daily by Hospitalized Patients
# Daily Meals
J. H. Kwon,
K. Reske, None
T. Hink, None
S. Seiler, None
C. A. D. Burnham, None
E. R. Dubberke, rebiotix: Consultant and Investigator , Consulting fee and Research support
sanofi-pasteur: Grant Investigator , Research grant
pfizer: Consultant , Consulting fee
Merck: Consultant and Investigator , Consulting fee and Research support
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