Aims
To evaluate a standard aerosolization method for uniformly depositing threat‐representative spores onto surfaces.
Methods and Results
Lyophilized Bacillus anthracis ΔSterne spores, coated in silica, were aerosolized into a containment chamber and deposited onto nine surface types by two independent laboratories. Laboratory A produced a mean loading concentration of 1·78 × 105 CFU cm−2; coefficient of variation (CV) was <40% for 96% of samples. Laboratory B produced a mean loading concentration of 7·82 × 106 CFU cm−2; 68% of samples demonstrated CV <40%.
Conclusions
This method has been shown to meet the goal of loading threat‐representative spores onto surfaces with low variability at concentrations relevant to the Department of Defense.
Significance and Impact of the Study
As demonstrated in 2001, a biological attack using anthrax disseminated as a dry powder is a credible threat. This method will provide a means to load spores onto surfaces that mimic a ‘real‐world’ scenario of an aerosolized anthrax attack. The method has utility for evaluating sporicidal technologies and for nondecontamination studies, for example fate and transport or reaerosolization.