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ARS Home » Research » Publications at this Location » Publication #75034
Title: DETECTION OF TRICHINELLOSIS IN SWINE BY ENZYME IMMUNOASSAY USING A SYNTHETIC GLYCAN ANTIGEN

Author
item Gamble, Howard
item WISNEWSKI, N - HESKA, FORT COLLINS, CO
item WASSOM, D - HESKA, FORT COLLINS, CO

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Trichinellosis, caused by the human pathogen Trichinella spiralis, is a significant cause of public health concern worldwide. Most developed countries, with the exception of the United States, inspect pork at slaughter for the presence of this parasite. Recent initiatives in the U.S. and the European Union are directed toward certifying trichinae- free management practices as a means of reducing the risk of trichinellosis. Once a farm is found to be trichinae-free and has no risk factors for transmission, swine originating from those premises would not require inspection. A necessary tool this type of pre-harvest program is a good serological test which can detect infected animals in a reliable manner. One such test for trichinellosis in swine is an enzyme immunoassay (EIA) based on the use of an antigen derived from in vitro culture of the parasite. Disadvantages of this assay are the need to produce antigen from live animals and the variability from batch to batch. In this study we have tested a synthetic carbohydrate antigen which is one of the major antigens found in Trichinella. Using this antigen in the EIA we were able to detect infected animals in a manner comparable to using the parasite derived antigens. Pending further testing using naturally-infected pigs, it may be possible to use the carbohydrate antigen in the EIA and thereby simplify the test for widespread use in an on-farm certification program.

Technical Abstract: A synthetic glycan antigen, B-tyvelose-GalNAc, was tested in an enzyme immunoassay (EIA) for detection of trichinellosis in pigs. A group of 47 pigs, experimentally-infected with various doses of Trichinella spiralis, were tested by EIA using an excretory secretory (ES) antigen and the synthetic glycan antigen. Forty-six of 47 pigs (97.8%) with worm burdens ranging from 0.02 to 248.8 larvae per gram (LPG) of tissue in the diaphragm became seropositive using both antigens. The time of seroconversion varied among pigs and was negatively correlated with intensity of infection. Minor differences were noted in times of seroconversion between the two antigens in 11 of 46 pigs, suggesting some differences in the antibody response. One pig with a worm burden of 0.01 LPG was not detected by EIA using either antigen. Background values obtained with the two antigens did not differ among confinement raised pigs, but background values for pigs raised outdoors on dirt lots were significantly lower using the glycan antigen. Pigs with low-level naturally-acquired infections with T. spiralis were detected by both antigens although there appeared to be some differences in the way infected animals antibody responses. The synthetic glycan antigen has potential as a standardized reagent for the diagnosis of trichinellosis in pigs.