Heat inactivation by high temperature as an approach to combat infections caused by airborne pathogens

The current pandemic of SARS-CoV-2 coronavirus infection has highlighted the importance of control measures to combat infections caused by airborne pathogens. Non-specific actions include various means of microorganism inactivation by chemical or physical methods targeting structural components of a given pathogen. Exposure of viruses and bacteria to elevated temperatures is one of the effective methods for discharging their harmful potential. Using a model of the Human Adenovirus 5 exposed to elevated temperatures with subsequent titration of the virus in vitro in A549 cells, we showed a dramatic decrease of the virus titer after heat treatment for 5 s at temperatures over 100°C. To verify the potential of the heat inactivation in a closed environment, the prototype of a high-capacity pathogen-cleaning device was constructed and tested. Application of the device for 2 h at an airflow rate of 900 m3/h in a room of 226 m3 reduced the total number of microorganisms in the air by more than 50% at all collection sites in the room.