Immunodiagnosis of swine trichinellosis.

A rapid, sensitive and specific serologic test has been developed for the diagnosis of swine trichinellosis. The ELISA based test utilizes L1 stichosome antigens recovered as excretory-secretory (ES) products from in vitro cultivated muscle larvae. Field studies conducted with 20,000 commercial swine using crude ES antigen demonstrated that the test could detect 98% of the medically significant infections. The test had a false-positive rate of less than 3%. Because of difficulties in regulating the quality and quantity of ES antigen and the need to continually maintain infected laboratory animals for producing the diagnostic reagent, efforts have been made to clone and express the gene(s) encoding the immunodominant ES antigens. To date a cDNA sequence, designated TsA-12, which codes in part for a 53-kDa ES antigen, has been identified and expressed in bacteria. Results demonstrate that TsA-12 is recognized by immune sera and further suggest that the immunodominant 45-, 48- and 53-kDa ES proteins which share antigenic epitopes are distinct glycoproteins.

Impact of biotechnology on trichinellosis control.

The century-old effort to rid Trichinella spiralis from the food supply has had variable success, and in some regions trichinellosis remains a serious public health concern. However, the research advanced during the past 5 years points toward greater success in developing practical and efficient control strategies. The application of monoclonal antibody and recombinant DNA technologies has permitted great improvement in diagnosis and production of diagnostic reagents. Further, the epidemiology of the disease has undergone considerable revision because of the power of DNA analytical technics which are unravelling the complex genetics of Trichinella spiralis. This improved understanding of the parasite's epidemiology is critical to the design of improved control strategies.