Transfer of Clostridium difficile spores by nonsporicidal wipes and improperly used hypochlorite wipes: practice + product = perfection.

To the Editor—Effective disinfection of contaminated surfaces is necessary to prevent transmission of Clostridium difficile spores. In addition to disinfection of rooms after discharge of patients with C. difficile infection (CDI), daily disinfection of surfaces may useful as a measure to decrease healthcare personnel hand contamination by reducing the burden of contamination on frequently touched surfaces.' Because C. difficile spores are resistant to killing by many disinfectants (eg, quaternary ammonium compounds), current guidelines recommend the use of sporicidal products such as sodium hypochlorite, particularly in outbreak or hyperendemic settings. In practice, it is not uncommon for healthcare facilities to use nonsporicidal products for some aspects of disinfection related to CDI (eg, daily cleaning of CDI rooms, equipment that may be damaged by exposure to hypochlorite). Rutala et al recently demonstrated that such use of nonsporicidal agents may be effective in reducing contamination on surfaces due to physical removal of spores (>2.9 log reduction). However, it is important for infection control practitioners to be aware that nonsporicidal wipes can transfer spores from contaminated to clean surfaces, and improper use of hypochlorite wipes can also reduce effectiveness. Here, we examined the potential for transfer of C. difficile spores by quaternary ammonium-impregnated wipes and by hypochlorite wipes used for longer than the recommended duration. Four wipes were tested: (1) Clorox premoistened germicidal wipes (Clorox), (2) used Clorox premoistened germicidal wipes (ie, a fresh wipe was used to wipe a clean surface area 25 ft long x 1 ft wide before testing, which resulted in drying within ~30 seconds after wiping a surface), (3) Kimtech Wet Task wipes (Kimberly-Clark) saturated with quaternary ammonium compound (VIREX II 256, JohnsonDiversey), and (4) Kimtech Wet Task wipes saturated with sterile water. The test organism was an epidemic North American pulsed-field gel electrophoresis type 1 isolate (VA 17). Spores were prepared as previously described. Transfer of spores was evaluated using a modification of the method of Williams et al. A clean bench top surface was inoculated with 5 log10 colony-forming unit (CFU) aliquots of C. difficile spores suspended in 10 /iL sterile water and allowed to air dry at room temperature for 30 minutes. The inoculation sites were manually wiped for 10 seconds with a wipe that was then sequentially wiped onto 4 clean sites for 10 seconds at each site. Each site was allowed 5 minutes of contact time before sampling with a sterile cotton-