A Review of Leucocytozoon caulleryi Infection in Chickens

Abstract

Leucocytozoon caulleryi is an etiological protozoan of chicken leucocytozoonosis commonly found in various Asian countries. Leucocytozoon caulleryi is transmitted by Culicoides biting midges and shows high infectivity and pathogenicity to chickens. The severity of clinical symptoms and mortality depend on the number of sporozoites inoculated. Severely infected chickens often die of hemorrhage, almost all of the chickens challenged with sporozoites after a primary infection at various ages show complete resistance to reinfection and the acquired immunity is expressed against the second generation of schizogony. Soluble antigens are found in the sera of chickens between the 10th and 15th day after sporozoite inoculation. These antigens originate from second-generation schizonts. Antibodies against the antigens of each developmental stage of L. caulleryi are recognized in the sera of infected chickens. Each stage is antigenically distinct.