Efficacy of liquid spray decontaminants for inactivation of Bacillus anthracis spores on building and outdoor materials

Abstract

Aims: To obtain data on the efficacy of various liquid and foam decontamination technologies to inactivate Bacillus anthracis Ames and Bacillus subtilis spores on building and outdoor materials. Methods and Results: Spores were inoculated onto test coupons and positive control coupons of nine different materials. Six different sporicidal liquids were spray‐applied to the test coupons and remained in contact for exposure times ranging from 10 to 70 min. Following decontamination, spores were recovered from the coupons and efficacy was quantified in terms of log reduction. Conclusions: The hydrogen peroxide/peracetic acid products were the most effective, followed by decontaminants utilizing hypochlorous acid chemistry. Decontamination efficacy varied by material type. Significance and Impact of the Study: The study results may be useful in the selection of technologies to decontaminate buildings and outdoor areas in the event of contamination with B. anthracis spores. These results may also facilitate selection of decontaminant liquids for the inactivation of other spore‐forming infectious disease agents.

Effect of inoculation method on the determination of decontamination efficacy against Bacillus spores

“…(2), is consistent with the reporting of log reduction (LR) as done in other relevant efficacy studies (U.S. EPA 2010, 2011b; Rastogi et al 2009, 2010; Calfee et al 2011; Wood et al 2011). However, in these citations, LR is typically reported as the inverse (i.e., log 10 (y o /y)).…”

Comparative evaluation of vacuum-based surface sampling methods for collection of Bacillus spores

“…Variability in positive control recoveries between trials (C v = 33.4%) and within trials (C v between 21.1 and 52.0%) was similar to that reported when liquid inoculation was used to dose coupons (Buhr et al, 2011; Calfee et al, 2011; Rastogi et al, 2009; Wood et al, 2011). Nonetheless, since the maximum and minimum recovery values for individual positive controls among the trials varied by more than 100% (maximum value was more than twice the minimum), and unlike direct liquid inoculations, absolute values for the amount of spores deposited onto the coupons surfaces are difficult to determine; vacuum-based recovery data were normalized by control recoveries (wipe samples of stainless steel).…”

Efficacy of sporicidal wipes for inactivation of a Bacillus anthracis surrogate

“…, ; Wood et al . ), there is continuing interest in expanding our understanding of commercially available products because of their wide availability, and ease of use. For these reasons, attention has been drawn to the potential use of disposable antimicrobial wipes designed for healthcare settings to combat Clostridium difficile , a bacterium with clinical relevance to the healthcare industry (McFarland and Stamm ; Weber et al .…”