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Figure 2 | BMC Veterinary Research

Figure 2

From: Accounting for uncertainty in model-based prevalence estimation: paratuberculosis control in dairy herds

Figure 2

(a) and (b) Density plots showing the distribution q (P) of simulated true within-herd prevalence, P , conditioned on P >0, as a function of time. Along a vertical line (at a fixed time) the density corresponds to the height of the distribution for different prevalences (similar to Figure 1(a) but for true rather than ELISA observed prevalence). (a) shows the distribution before applying the reweighting algorithm, (b) shows the same distribution with reweighting. Also shown are the first, second (median) and third quartile boundaries of these distributions as a function of time, with the median shown by the solid white line and the outer quartiles by the dotted lines. The initial condition has no infected individuals but the environmental contamination equivalent to a single high shedding animal. It can be seen that the distributions approach equilibrium. (c) shows the time dependence of the corresponding herd level prevalence (i.e. the proportion of farms with infected animals) comparing the value before (circles) and after (triangles) the reweighting. (d) The distribution p(P) for both non-weighted (circles) and weighted models (triangles), at a single timepoint where the system is deemed to be in equilibrium.

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