Evaluation of the Prevalence and Transmission of Asymptomatic Clostridioides Difficile Carriage in the Hamilton In-patient Setting Using Multi-level Modelling

Abstract

Background: C. difficile is one of the primary infectious causes of morbidity and mortality in Canada. Colonized patients can pose a risk to others as a factor in the transmission and development of hospital-associated C. difficile infections. Despite immense efforts and resources invested in the reduction in C. difficile transmission within Canada and Hamilton Health Sciences – further reduction in these rates are unlikely, and novel screening strategies are imperative in this field of study.

Methods: This project was a retrospective cohort study of adult in-patients admitted to either The Juravinski, Hamilton General, or St. Joseph’s Healthcare Hamilton Hospitals from January to April 2018 and September 2018 to August 2019. MSRA/VRE swabs were collected during admission or through universal point prevalence screening and subsequently tested for colonization.

Results: From the 1056 patients in the data sample, 72 were colonized with asymptomatic C. difficile resulting in a prevalence rate of 6.81%. In-patient point prevalence screening strategies identified more carriers than admission swabs alone (p < 0.001). Risk factors for colonization on admission were being female (OR 2.66, 95% CI 1.02-8.33) and previous CDI (OR 4.76, 95% CI 1.49 – 13.86). During hospitalization, risk factors for colonization were previous CDI (OR 4.75 95% CI 2.14-9.94) and recent hospitalization within the last 12 months (OR 2.35, 95% CI 1.30-4.42). The multi-level Cox PH model identified those with a recent hospitalization (OR 2.21, 95% CI 1.32 – 3.73) and those with previous CDI (OR 2.40, 1.34 – 4.30) were twice as likely to develop asymptomatic C. difficile colonization throughout hospitalization.

Conclusion: The addition of universal point prevalence screening in addition to admission screening helped identify more than double the amount of carriers in the population. Moreover, a previous hospitalization, previous CDI, and being female may indicate patients at the highest risk of colonization.