Coccidiosis is a disease caused by Eimeria parasites that are commonly observed in the intestinal tract of mammals and birds. In chickens and turkeys, infection by this parasite is costly to both the producer (higher feed conversion ratios, depressed growth and increased flock mortality) and the industry, causing billions of dollars in losses worldwide. While environmental management and anticoccidials (ionophores and chemicals added to the feed) have been the most common forms of prevention in the past, vaccination is quickly becoming a popular and successful option.
In 1910, H. B. Fantham, a parasitologist at the University of Cambridge, UK, described the life cycle of the coccidiosis parasite in birds. Further progress in coccidiosis research was made about 30 years later at Harvard University – USA, by E. Tyzzer. His studies laid the foundations of our contemporary understanding of coccidiosis and the Eimeria species involved in this illness. The results from the studies conducted by W. T. Johnson at Western Washington,
Oregon Agricultural Experiment Station can also be added to these achievements, as a major contribution in the field (Chapman, 2003).