Figure 3

Comparison of spatial transmission kernels used in between-farm transmission model. Hill et al. [47] and Backer et al. [74] used the same kernel and same parameter values as Hill et al. [46] and Boender et al. [71], respectively. Note that for Rorres et al. [54, 55] and Pelletier et al. [50], estimated parameter values were close and therefore the three curves are indistinguishable. For these three models, although the relative risk of transmission between farms decreased to very low values at small distances, the absolute probability of transmission remained substantial even at long distances because the sizes of both susceptible and infectious farms were included in the force of infection.