Figure 2From: Quantification of transmission of foot-and-mouth disease virus caused by an environment contaminated with secretions and excretions from infected calves The 2R- SIR model. The combined transmission rate parameter (β contact+environment ) depends on the number of infectious calves (It) and/or on the amount of virus in the environment (Et). Et depends on FMDV secretion and excretion by the infected calves on previous days (t-1) and on the remaining amount of FMDV in the environment weighted by σ.Back to article page