Coccidiosis in Poultry: An Overview

Introduction Coccidiosis is one of the most important diseases of poultry caused by protozoa, Eimeria and is generally characterized by bloody diarrhea, the primary symptom and high mortality. The bloody diarrhea is mainly due to intestinal epithelium dying off since a large number of oocysts and merozoites burst out of the cells. The disease spreads from one bird to another by contact with infected feces or ingestion of infected tissue. Thus it is a major problem in intensively reared poultry. Despite recent advances in control and treatment, the disease remains one of the most expensive and common disease of poultry worldwide. In India, coccidiosis is a serious problem and is one of the biggest causes of economic losses in poultry. It inflicts heavy mortality each year mainly in broilers and also in grower raised on deep litter by impairing the growth and feed utilization of infected birds. The comparison of economic traits revealed the maximum loss due to reduced body weight gain, followed by increased FCR and chemoprophylaxis. Control of coccidiosis by the poultry industry is dominated by prophylactic chemotherapy but drug resistance is a serious problem. Because of the complexity of the host immunity and the parasite life cycle, a comprehensive understanding of hostparasite interactions and protective immune mechanisms becomes necessary for successful prevention and control practices.