An opinion on the multi-scale nature of Covid-19 type disease spread

Chaudhuri, Swetaprovo; Saha, Abhishek; Basu, Saptarshi

Recognizing the multi-scale, inter-disciplinary nature of the Covid-19 transmission dynamics, we discuss some recent developments concerning an attempt to construct a disease spread model from the flow physics of infectious droplets and aerosols, and the frequency of contact between susceptible individuals with infectious aerosol cloud. Such an approach begins with the exhalation event specific, respiratory droplet size distribution (both airborne/aerosolized and ballistic droplets), followed by tracking its evolution in the exhaled air to estimate the probability of infection and the rate constants of the disease spread model. The basic formulations and structure of sub-models, experiments involved to validate those sub-models are discussed. Finally, in the context of preventive measures, respiratory droplet-face mask interactions are described.