Toilet plume aerosol generation rate and environmental contamination following bowl water inoculation with Clostridium difficile spores

Published:December 14, 2018DOI:



      Clostridium difficile is the leading cause of health care–associated gastric illness. Environmental contamination with C difficile spores is a risk factor for contact transmission, and toilet flushing causes such contamination. This work explores toilet contamination persistence and environmental contamination produced over a series of flushes after contamination.


      A flushometer toilet was seeded with C difficile spores in a sealed chamber. The toilet was flushed 24times, with postflush bowl water samples and settle plates periodically collected for culturing and counting. Air samples were collected after each of 12 flushes using rotating plate impactors.


      Spores were present in bowl water even after 24 flushes. Large droplet spore deposition accumulated over the 24-flush period. Droplet nuclei spore bioaerosol was produced over at least 12 flushes.


      Toilets contaminated with C difficile spores are a persistent source of environmental contamination over an extended number of flushes.

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