Multi-route respiratory infection: when a transmission route may dominate

Caroline X. Gao; Yuguo Li; Jianjian Wei; Sue Cotton; Matthew Hamilton; Lei Wang; Benjamin J Cowling

Another important difference in our model compared to previous work is that we considered the evaporation process of respiratory droplet as well as the airborne ability related to the final size rather than initial size. Respiratory activities mostly generate substantial number of droplets between 0 and 50 µm. Droplets with the initial diameter of 10 µm (with a volume 1000 times larger than a 1 µm droplet) will evaporate quickly to a diameter of about 3 µm, which can then penetrate into the lower respiratory track. Using an airborne cut-off size of =5 µm, about 60% of respiratory droplets generated ( 0 =15 µm) can be evaporated and suspended in the air and introduce long-and short-range airborne infection, which is largely underestimated in other studies.