Environmental shedding of toxigenic Clostridioides difficile by asymptomatic carriers: A prospective observational study.

To compare the burden of environmental shedding of toxigenic C. difficile among asymptomatic carriers, C. difficile infected (CDI) patients and non-carriers, in an inpatient non-epidemic setting.C. difficile carriage was determined by positive toxin-B PCR from rectal swabs of asymptomatic patients. Active CDI was defined as a positive 2-step EIA/PCR test in patients with >3 unformed stools/24 hours. C. difficile environmental contamination was assessed by obtaining specimens from 10 sites in the patients' rooms. Toxigenic strains were identified by PCR. We created a contamination scale to define the overall level of room contamination that ranged from clean to heavy contamination.117 rooms were screened; 70 rooms inhabited by C. difficile carriers, 30 rooms by active CDI patients and 17 rooms by non C. difficile -carriers (Control). In the carrier rooms 29 (41%) had more than residual contamination, from which 17 (24%) were heavily contaminated. In the CDI rooms 12 (40%) had more than residual contamination from which 3 (10%) were heavily contaminated, while in the control rooms, one room (6%) had more than residual contamination and none were heavily contaminated. In a multivariate analysis, the contamination score of rooms inhabited by carriers did not differ from rooms of CDI patients, yet both were significantly more contaminated than those of none carriers OR 12.23 and 11.16 (95%CI:1.5-99.96 P=0.0195, and 1.19-104.49 p=0.035), respectively.Here we show that C. difficile carriers' rooms are as contaminated as those of patients with active CDI and significantly more than those of non-carriers.