ABSTRACT
In China, poultry coccidiosis caused by Eimeria parasites was first reported in the early 1950s. The poultry production emerged in China in the late 1950s. Coccidiosis research in China before 1991 was mainly driven by field problems, viz., mortality, poor performance, and lost productivity caused by Eimeria infection. The sporogony process of Eimeria is vital for the transmission of coccidiosis. Cellular immune responses are the major force of immunity against intracellular Eimeria infection. One most intriguing immunological question is how many of the 5000–8000 proteins expressed by Eimeria parasites are recognized by the host immune system. Eimeria infection causes apoptosis in both infected cells and noninfected neighbor cells through mitochondria-dependent apoptotic pathways. Coinfection of chickens with Eimeria and viruses and/or bacteria is extremely common. Eimeria as a vaccine vector expressing heterogeneous antigens to elicit protective immunity has been proven feasible.
