Exposure of swine to Trichinella spiralis antigen as determined by consecutive ELISAs and western blot.

Exposure of swine to Trichinella spiralis was evaluated using a combination of 3 consecutive enzyme-linked immunosorbent assays (ELISAs) based on larval T. spiralis excretory-secretory antigen as screening test and western blot analysis as confirmatory test. Ninety-three of 32,693 domestic swine sera collected in Georgia over a 5-yr period contained antibodies specific to T. spiralis (prevalence of exposure = 0.28%). The highest prevalence (0.52%) of exposure to T. spiralis was in samples from stockyards and salebarns. Prevalence of exposure in samples from cull sows from 1 slaughter house was 0.38% compared with 0.17% in samples obtained from farms. Pepsin-HCl digestion of diaphragms from 49 swine from 6 seropositive farms revealed 0.01 larvae/g in 4 swine from 3 farms. Determination of T. spiralis infection status of farms appears to be accurately determined with this combination of exploratory ELISAs and confirmatory western blot analysis.