Efficacy of sporicidal wipes for inactivation of a Bacillus anthracis surrogate

To evaluate five commercially available sporicidal wipes and two disinfecting wipes for their ability to inactivate Bacillus atrophaeus spores deposited onto various material surfaces.

Decontamination efficacy of the wipes was initially tested on glass Petri dishes (150 mm diameter). Following exposure for a specified time of contact, survival of the spores was assessed by quantification of the remaining viable spores, both on the coupon surface and on the towelette itself, with efficacy quantified in terms of mean log reduction. Based on these data, five wipes were down-selected for evaluation on a larger scale, using 36 × 36 cm coupons of five different material types.

Results suggest that sodium hypochlorite-based sporicidal wipes were most effective, having completely inactivated the Bacillus spores on the glass Petri dish and several materials. Additionally, results demonstrate that the manufacturer-prescribed contact times for Clostridium difficile achieved a 6 log10 reduction of B. atrophaeus spores. Moreover, commercially available disinfecting wipes were not able to kill Bacillus spores as evaluated.

These data show the potential of sporicidal wipes for decontamination of small, contained areas of biological contamination and may help on-scene coordinators develop remediation plans following a biological terrorism event.