Theileria annulata schizonts found in calf kidney cell culture.

Mononuclear cells infected with Theileria annulata schizonts were isolated at 4 different times from monolayer cultures of primary kidney cells derived from apparently healthy, 2 to 6 weeks old zebu calves. The presence of such an organism could interfere with the manufacturing procedure of rinderpest tissue culture vaccine if it is to be carried out in calf kidney cell culture.