Date of Award

January 2023

Document Type


Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Windy Tanner


Clostridioides difficile is a major public health threat and frequent cause of healthcare-associated infections. Hospitals have struggled to control C. difficile due in part to the challenge of identifying asymptomatic C. difficile carriers and because of C. difficile’s ability to survive on environmental surfaces for long periods. Asymptomatic carriers and environmental surfaces can contribute to C. difficile transmission. Screening of all patients for C. difficile upon hospital admission is not feasible and asymptomatic patients may not be accepting of surveillance testing. Thus, this study examines whether sampling the patient’s room environment once they have been admitted can indicate a patient being colonized with C. difficile. For a secondary analysis, this study also examines whether environmental sampling can be used as a predictor of patient’s colonization status when the patient does not have a sample. Data and samples were obtained from a prior study of the transmission of healthcare-associated infections in hospital intensive care units. Approximately 7,000 samples included in a dataset were examined and cleaned to identify possible predictors that would impact C. difficile positivity. To determine if these variables are predictors for positive C. difficile colonization logistic regression and random forest techniques were used. A total of six models were created, where four primary analysis models had 95.7 %, 94.6%, 95.7% and 94.5% accuracy scores in identifying whether patients were colonized for C. difficile patients. The two models for the secondary analysis had accuracy scores of 14.7 percent (logistic regression) and 60.9 percent (random forest). In conclusion, the findings indicate that room environment testing has the potential to identify a patient’s C. difficile colonization status but should not be used as the only method to determine if a patient is positive or negative for C. difficile.


This thesis is restricted to Yale network users only. It will be made publicly available on 11/10/2023