|Yai, Lucia E|
Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2005
Publication Date: 3/4/2006
Citation: Hoane, J.S., Gennari, S.M., Dubey, J.P., Ribeiro, M.G., Borges, A.S., Yai, L.O., Aguiar, D.M., Cavalcante, G.T., Bonesi, G.L., Howe, D.K. 2006. Prevalence of sarcocystis neurona and neospora spp. infection in horses from Brazil based on presence of serum antibodies to parasite surface antigen. Veterinary Parasitology. 136:155-159. Interpretive Summary: Sarcocystis neurona is a single-celled parasite. It causes a fatal disease in horses called Equine Protozoal Myeloencephalitis (EPM). EPM also occurs in other animals. Opossums are the definitive host for this parasite, and the main reservoir of infection. Opossums become infected by consuming the encysted stage of the parasite (sarcocyst) in infected animal tissue and they excrete millions of the resistant stage (oocysts) in their feces. Horses become infected by ingesting food and water contaminated with oocysts. Scientists at the Beltsville Agricultural Research Center and the Univ. of Kentucky , Lexington, Kentucky have found that S. neurona is widely prevalent in horses in Brazil. The results will be of interest to biologists, parasitologists, and veterinarians.
Technical Abstract: Sera from 961 horses from Brazil were tested for antibodies against the major surface antigens SnSAG4 and NhSAG1 to determine the seroprevalence of Sarcocystis neurona and Neospora hughesi, respectively. Antibodies against SnSAG4 were detected in 669 (69.6%) of the horses, while antibodies against NhSAG1 were detected in only 24 (2.5%) of the horses. These serologic results suggest that there is a high concentration of S. neurona in the environment of Brazil, which results in significant exposure of horses to this parasite. Additionally, the data further confirm that infection with Neospora spp. is relatively uncommon in horses.