Effect of combined variations of the four most influential phenotypic traits on cumulative incidence. Cumulative incidence was calculated 25 years after initial Map introduction. The external dashed circle corresponds to the lowest cumulative incidence (0.35 newly infected animals) obtained among tested scenarios (log10(0.35) = − 0.46), the internal dashed circles correspond to thresholds of 25 (log10(25) = 1.39) and 12 (log10(12) = 1.09) newly infected animals. Asterisk corresponds to the cumulative incidence (log10(617) = 2.79) for the scenario with current values of phenotypic traits. h, decay in susceptibility with age; α, increased required infectious dose; ν
, increased duration before high shedding or clinically affected state; ϕFeces
, decreased quantity of bacteria shed by high shedders or clinically affected animals. Each leaf is one scenario with branches representing variations of the four traits. Scenarios are presented by increasing level of variation in each trait successively (h, α, ν
, and, ϕFeces
). Tested values are given in Table 1.