Fig 1.
Diagrammatic representation of Mbovis physiopathology and possible distribution of biomarkers associated with ELISA and qPCR testing, with corresponding latent condition for LCA.
Table 1.
Parameters of prior Beta distributions for the main analyses.
Table 2.
Apparent seroprevalence for the slaughter sampling round (Delimiting population) and for National Beef Cattle Surveillance population, at different levels of ELISA SP% thresholds.
Fig 2.
Proportion of herds in four categories of within-herd prevalence during the first round of on-farm testing (Delimiting population) at the 60 SP% ELISA threshold.
Fig 3.
Overall apparent seroprevalence by sampling round in the Programme (Delimiting population), at threshold SP%=60.
The round denoted “S” represents the slaughter sampling round.
Fig 4.
Correlation in titres between two subsequent rounds in the same animal with marginal titre distribution.
In red the SP%=60 positivity threshold for both distributions, in blue the abline y = x, upper right quadrant T1+T2+ (proportion = 1.64%), upper left quadrant T1-T2+ (proportion = 1.13%), lower right quadrant T1+T2- (proportion = 1.04%), lower left quadrant T1-T2- (proportion = 96.19%).
Table 3.
Apparent seroprevalence (SP% threshold = 60 or 90) and prevalence of positive qPCR for cattle in farms from the North versus the South Island, in the slaughter population.
Fig 5.
LCA model results (Median and CI) for varying levels of ELISA positivity threshold.
Table 4.
Estimated accuracy estimates for ELISA and qPCR for LCA models using ELISA positivity thresholds of SP% = 60 or 90).
Table 5.
Estimated overall true prevalence of infection for cattle from the North versus the South Island, in models using ELISA positivity thresholds of SP%=60 or 90.
Table 6.
Summary measures of probabilities Cp and Cn for ELISA positivity thresholds of SP%=60 or 90 (expressed in percentages).
Table 7.
Summary measures of test accuracy and true prevalence estimates of”exposure to Mbovis” in the slaughter population, using constrained specificity priors inferred from the National Beef Cattle Surveillance data, for ELISA positivity threshold of SP%=60 or 90.
Fig 6.
Summary measures of test accuracy and true prevalence estimates of “exposure to Mbovis” in the slaughter population.
Obtained with constrained ELISA specificity priors using information from National Beef Cattle Surveillance, for ELISA positivity threshold of SP%=60 (left) or 90 (right).
Fig 7.
Proportion of misclassified herds (scenario 1).
Fig 8.
Proportion of misclassified herds (scenario 2).