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

Abstract

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

Time series analysis 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 three 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 (i.e. for either CDI or carriage) per 1,000 patient-days between study periods. Changes in trend were analyzed by segmented regression analysis.

Results

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 1,000 patient-days, respectively (p<0.001 between periods). Isolating CD carriers was associated with an increase in isolation-days prevalence compared with period 2 (Risk Ratio [RR], 1,66; p<0.001) followed by a significant decrease in trend (RR per four-week period, 0.97; p<0.001). The downward trend was mainly due to decreasing isolation needs for patients with CDI (RR per four-week period, 0.94; p<0.001) rather than for carriage (RR per four-week period, 0.996; p=0.21).

Conclusions

Isolating CD carriers led to an initial increase in isolation needs that was partially compensated by a decrease in isolation needs for CDI.