Hot, humid air decontamination of a C-130 aircraft contaminated with spores of two acrystalliferous Bacillus thuringiensis strains, surrogates for Bacillus anthracis.

AimTo develop test methods and evaluate survival of Bacillus thuringiensis kurstaki cry(-) HD-1 and B.thuringiensis Al Hakam spores after exposure to hot, humid air inside of a C-130 aircraft. Methods and ResultsBacillus thuringiensis spores were either pre-inoculated on 1x2 or 2x2cm substrates or aerosolized inside the cargo hold of a C-130 and allowed to dry. Dirty, complex surfaces (10x10cm) swabbed after spore dispersal showed a deposition of 8-10 log(10)m(-2) through the entire cargo hold. After hot, humid air decontamination at 75-80 degrees C, 70-90% relative humidity for 7days, 87 of 98 test swabs covering 098m(2), showed complete spore inactivation. There was a total of 167log(10) live CFU detected in 11 of the test swabs. Spore inactivation in the 98 test swabs was measured at 706log(10)m(-2). ConclusionsLaboratory test methods for hot, humid air decontamination were scaled for a large-scale aircraft field test. The C-130 field test demonstrated that hot, humid air can be successfully used to decontaminate an aircraft. Significance and Impact of the StudyTransition of a new technology from research and development to acquisition at a Technology Readiness Level 7 is unprecedented.