Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 22, 1999
Publication Date: N/A
Interpretive Summary: Toxoplasma gondii is a single-celled parasite of humans and livestock. It causes mental retardation and loss of vision in congenitally infected children and abortion in livestock. Ingestion of infected meat and ingestion of food or water contaminated with oocysts are the 2 major modes of transmission of Toxoplasma gondii to humans. Among the major food animals, viable T. gondii has been found in pork, mutton, chickens, and horse meat in the U.S. Little is known of the prevalence of T. gondii in horses. Scientists at the Beltsville Agricultural Research Center and the Institute of Pureculture in Paris, France found T. gondii antibodies in 6.9% of 1788 horses slaughtered for export. The results suggest that the prevalence of T. gondii in horses is low and thus the risk of acquiring Toxoplasma from eating horse meat may not be great. These findings will be useful to parasitologists and public health workers.
Serum samples from 1788 horses slaughtered for food in North America were tested for antibodies to Toxoplasma gondii using the modified direct agglutination test (MAT). Antibodies to T. gondii were found by the MAT in 124 (6.9%) of 1788 sera; the titers were 1:20 (69 horses), 1:40 (37 horses), 1:80 (9 horses), and ò1:160 (9 horses). A total of 339 selected horses were also tested by the Sabin-Feldman dye test (DT). Dye test antibodies were found in 54 horses with titers of 1:10 (29 horses), 1:20 (12 horses), 1:40 (4 horses) and 1:80 (9 horses). There was no correlation between the DT and the MAT.