Compartments and transmission routes.

<p>The upper part of the figure models the flow of individual compartments. The transfer rate from susceptible (<i>S</i>) to infected (<i>I</i>) is the product of the pathogen amount on hands of susceptible (<i>E_HS</i>), the fraction of pathogens <i>E_HS</i> transferred to mucus of susceptible via inoculation (<i>ρ_inoc</i>) and the probability that a susceptible individual becomes infectious per pathogen. The recover rate of infected is <i>γ</i> per unit time. The lower part of the figure models the flow of pathogens. <i>α</i> is the shedding rate per unit time per individual. <i>φ_H</i> proportion of virus goes directly to the hands of an infected individual. The proportion of virus that is excreted to hands and then is associated with a type of fomite is <i>ξ</i>. <i>λ</i> is the fraction of pathogens going to surfaces reach one type of fomite. <i>ρ_F</i> is the individual pick up rate of pathogens on a fomite per unit time and <i>δ</i> is the deposit rate of pathogens from hands to fomites per unit time. <i>µ</i><i>_H</i> and <i>µ</i><i>_F</i> are virus inactivation rate on hands and fomites respectively.