Specificity of three ELISA-gE kits for screening pig meat for antibodies to Aujeszky's disease.

Muscle samples (20 g) from 2025 pig carcases from Aujeszky's disease-free holdings were collected at the slaughterhouse. The samples were frozen and thawed to obtain meat juice, which was then analysed by three ELISA-gE test kits in parallel, to assess their specificity. After two cycles of freezing and thawing, 2.2 per cent of the samples were dry. Three times more of the samples from the sow carcases than from the finisher carcases yielded insufficient juice (< 220 microl). To validate the results of the specificity study, the sensitivity of the test kits was evaluated on 45 samples from gE-seropositive sows. On the basis of the results from 1879 samples, the specificity of the ELISA-gE kits was between 0.995 and 1.000, depending on the classification of the doubtful results. In the case of a positive or doubtful result, it proved useful to repeat the test on the same sample, in order to limit the number of false positive results.