Figure 1

Graphical description of the simulation model. (a) Model 1 (transmission): the rate at which hens in a laying flock are colonized as a result from S. Enteritidis excreted by a single hen (i). Model for a hen with mean infectivity level (X) of 6.8, based on the pairwise experiments; (b) Model 2 (immunological sampling and testing): sensitivity of egg yolk immunology as a function of time since colonization, based on the pairwise experiments; (c) Model 3 (bacteriological sampling and testing): sensitivity of cloacal swab culture as a function of time since colonization, based on the pairwise experiments (___), group-experiment 3 (_ .. _ ..), group-experiment 1 (....), and group-experiment 2 (_ _ _).