Ask the Editors
Why is the destruction of Mycobacterium tuberculosis required by the EPA as the benchmark for classification of a disinfectant as an intermediate-level disinfectant?
M. tuberculosis is not transmitted via contaminated inanimate surfaces, such as counter tops. Its major mode of transmission is through the inhalation of infectious microdroplet nuclei created from infectious aerosols. This vegetative, acid-fast bacillus serves as the resistance standard for disinfectants primarily because of its resistance to germicidal chemicals. According to the EPA classification, approved label claim of “hospital disinfectant” assures that the product has a demonstrated ability to kill Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica. The additional claim of “tuberculocidal” activity provides the level of microbial inactivation appropriate for contaminated clinical contact environmental surfaces in healthcare facilities – “intermediate-level” disinfection. The ability of a disinfectant to destroy the more resistant tubercle bacilli leads to the consistent inactivation of less resistant vegetative bacteria, fungi, and viruses.