|LILLEHOJ HYUN S|
|TROUT JAMES A|
Submitted to: Parasitology Today
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/1994
Publication Date: N/A
Interpretive Summary: Coccidiosis is an intestinal infection caused by intracellular protozoan parasites. Coccidiosis causes $450 million in annual losses to the poultry industry due to the need for medication and bird mortality. A vaccine for coccidiosis is not currently available. However, an enhanced understanding of host-parasite interactions will soon enable new approaches to vaccination against coccidiosis. In this review, ARS scientists summarize their work on host immunity to coccidiosis to suggest that cell-mediated responses are the main line of defense against coccidial infection. These studies will provide crucial information necessary for the development of a vaccine for coccidiosis.
Technical Abstract: Avian coccidiosis is caused by intracellular protozoan parasites belonging to several different species of Eimeria. Coccidia seriously impair the growth and feed utilization of livestock and poultry. The desire to develop vaccines against coccidian parasites has prompted immunological studies. Although detailed immune mechanisms involved in protection against coccidia remain to be determined, cell-mediated immune mechanisms have been shown to play a major role in disease resistance. Recent studies on host immunity to avian coccidia suggested a major effector role for CD8+ cells. Unlike other protozoan parasites, however, the primary target tissue for coccidia is intestinal epithelium. Thus, understanding T lymphocyte-parasite interactions in the gut leading to parasite elimination is crucial for the design of an effective vaccine. Enhanced understanding of interactions between coccidian parasites and the host's intestinal immune system will soon enable new approaches to vaccination against coccidiosis.