Avian Coccidiosis: recent advancements in control measures and vaccine development

Authors: DALLOUL, AMI - VISITING SY; Lillehoj, Hyun

Submitted to: Expert Review of Vaccines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2006
Publication Date: 10/25/2006
Citation: Dalloul, A.A., Lillehoj, H.S. 2006. Avian Coccidiosis: recent advancements in control measures and vaccine development. Expert Review of Vaccines. 5:143-163.

Interpretive Summary: Avian coccidiosis is the major parasitic disease of poultry with substantial economic burden estimated to cost the industry greater than $3 billion in annual losses worldwide. In feed medication for prevention and treatment contributes a major portion of those costs and losses are also due to mortality, malabsorption, inefficient feed utilization and impaired growth rate in broilers. Good management practices and hygiene help in reducing the spread of coccidiosis, but prophylactic medication and/or vaccination are absolute requirements to control the disease. Coccidiosis is caused by several apicomplexan parasites of the genus Eimeria that infect the gut and are transmitted between birds via ingestion of infective oocysts. In this comprehensive review, ARS scientists provide latest information on disease prevention and novel control strategies for avian coccidiosis. At present, the lack of long term and efficient vaccines, the increasing incidence of drug resistant Eimeria, and the escalating public anxiety over chemical residues in meat and eggs mandate the development of alternative control methods. This paper provides comprehensive understanding of poultry immune system and the means to elicit effective immunity against coccidia that will benefit poultry scientists and industry to develop a new control strategy against coccidiosis.

Technical Abstract: Coccidiosis is recognized as the major parasitic disease of poultry and is caused by the apicomplexan protozoa Eimeria. Coccidiosis seriously impairs the growth and feed utilization of infected animals resulting in loss of productivity. Conventional disease control strategies rely heavily on chemoprophylaxis and to a certain extent on live vaccines. These factors combined inflict tremendous economic losses to the world poultry industry in excess of $3 billion annually. Increasing regulations and bans on the use of anticoccidial drugs coupled with the associated costs in developing new drugs and live vaccines urges the need for developing novel approaches and alternative control strategies for coccidiosis. The aim of this paper is to review the current progress in our understanding of the host immune response to Eimeria and to discuss current and potential strategies being developed for coccidiosis control in poultry.