Evaluation of Western blot, ELISA and latex agglutination tests to detect Toxoplasma gondii serum antibodies in farmed red deer

At optimised cut-off S/P of 15.5%, the sensitivity (98.8%, 95% credible interval 96.1-99.8%) and specificity (92.8%, 95% credible interval 88.9-95.7%) of the ELISA were higher and lower, respectively, than the sensitivity (85.1%, 95% credible interval 76.2-91.9%) and specificity (98.5%, 95% credible interval 96.9-99.4%) at manufacturer's cut-off S/P of 30%, from BLC analysis. The sensitivity and specificity of ELISA at S/P cut-off of 15.5% was 91.1% (95% CI: 83.2-96.1%) and 90.7% (95% CI: 85.2-94.7%), respectively, when assessed against WB. The sero-prevalence from ELISA and LAT, at cut-off of S/P 15.5% and ≥1:64, respectively, was not significantly different to that from WB (McNemar's Chi-square p = 0.21 for ELISA and p = 0.28 for LAT).