Impact of Isolating Clostridium difficile Carriers on the Burden of Isolation Precautions: A Time Series Analysis

Background. The isolation of asymptomatic Clostridium difficile (CD) carriers may decrease the incidence of hospital-associated C. difficile infections (CDI), but its impact on isolation precaution needs is unknown. Methods. A time series analysis was conducted to investigate the impact of isolating CD carriers on the burden of isolation precautions from 2008 to 2016 in a Canadian hospital. To account for the changes in C. difficile infection control policies, the series was divided into 3 intervention periods: period 1 (2008-2011), isolation of patients with CDI until symptom resolution; period 2 (2011-2013), isolation of patients with CDI until discharge; and period 3 (2013-2016), isolation of patients with CDI and CD carriers until discharge. We compared the prevalence of isolation-days for C. difficile (ie, for either CDI or carriage) per 1000 patient-days between study periods. Changes in trend were analyzed by segmented regression analysis. Results. A total of 806 357 patient-days and 20 455 isolation-days were included. Isolation-day prevalence during periods 1, 2, and 3 were 12.9, 26.2, and 37.8 isolation-days per 1000 patient-days, respectively (P <.001 between periods). Isolating CD carriers was associated with an increase in isolation-days' prevalence compared with period 2 (rate ratio [RR], 1.66; P <.001) followed by a significant decrease in trend (RR per 4-week period, 0.97; P <.001). The downward trend was mainly due to decreasing isolation needs for patients with CDI (RR per 4-week period, 0.94; P <.001) rather than for carriage (RR per 4-week period, 0.996; P =.21). Conclusions. Isolating CD carriers led to an initial increase in isolation needs that was partially compensated by a decrease in isolation needs for CDI.