Outbreaks of infectious respiratory diseases have become an important issue worldwide and have drawn people's attention studying them with a view to providing better means for prevention. Pathogens causing infectious respiratory diseases are normally carried by the expiratory particles and they can be transmitted through airborne and droplet modes. However, due to the complicated transport characteristics, it is a challenging task to investigate the transmission of infectious respiratory diseases. In this research, disease transmissions were studied according to the different pathways. Exposure levels of susceptible people were estimated by the model developed and subsequently input into the risk model to quantify the probability of acquiring infection for a certain type of dis...[ Read more ]

Outbreaks of infectious respiratory diseases have become an important issue worldwide and have drawn people's attention studying them with a view to providing better means for prevention. Pathogens causing infectious respiratory diseases are normally carried by the expiratory particles and they can be transmitted through airborne and droplet modes. However, due to the complicated transport characteristics, it is a challenging task to investigate the transmission of infectious respiratory diseases. In this research, disease transmissions were studied according to the different pathways. Exposure levels of susceptible people were estimated by the model developed and subsequently input into the risk model to quantify the probability of acquiring infection for a certain type of disease. Experiments were conducted to study the aerodynamic properties of pathogen-laden particles in test chamber using particle image velocimetry techniques. A case study of a previous disease outbreak was conducted to demonstrate the applicability of proposed method.

Infectious respiratory disease transmission was studied according to different pathways. For the indirect contact transmission route, the results indicated that human behavior has a relatively higher impact on the disease transmission than that of the ventilation rate. By comparing the infection risk using three selected diseases, it was found that the infection risk could be reduced by 3 orders of magnitude if the proper surface materials in indoor environments were used. Besides indirect contact transmission of disease, airborne expiratory particles could serve as carriers for virus pathogens, as well as for bacterial pathogens. Results of respiratory disease infection risk assessments indicated that the airborne route contributes higher infection risks than the indirect contact route does in indoor environments. When considering bacterial pathogens via the airborne route, the results could be substantially different if the aerodynamic particle diameters were ignored. This research also demonstrates the applicability of the proposed exposure model and risk model integrated with the aerodynamic particle diameters.