DETECTION OF TRICHINOSIS IN PIGS BY ARTIFICIAL DIGESTION AND ENZYME-IMMUNOASSAY

The objective of this study was to demonstrate the reliability of curr ent and proposed methods for the inspection of swine and other species for infection with the parasite Trichinella spiralis. Five groups of pigs were infected with doses of 2500, 500, 100, 50, and 20 T. spirali s larvae to establish moderate and low-level infections. Pigs were ble d periodically during the study for samples to be tested by enzyme imm unoassay (EIA). At the conclusion of the study, pigs were slaughtered and tissues collected for analyses of worm burdens and for comparison of digestion testing methods. Comparisons of pooled sample digestion m ethods were made using inspection methods prescribed by European Union Directives and the USDA, Code of Federal Regulations. Pooled sample d igestion testing using 1-g samples was effective for detecting pigs wi th larval densities of >10 larvae per gram (LPG) of tissue but only pa rtially effective for pigs with infections of <3 LPG. Pooled sample di gestion testing using 5-g samples detected all pigs with infection lev els >1 LPG. The ELA detected all T. spiralis-infected pigs, but did no t detect infections in some pigs until 49 days after inoculation. Thes e results demonstrate that the pooled sample digestion method using a 5-g sample size is the most effective inspection method for reducing t he risk of human exposure to T. spiralis in pork.