A new experimental system for Theileria orientalis sergenti infection by using a bovine erythrocyte-substituted SCID mouse and a tick(Haemaphysalis longicornis) was established. The development of the Theileria parasite in a tick was different for each race of Haemaphysalis longicornis. (Lab. of Protozoan Diseases, Department of Bacteriology and Parasitology TEL +81-298-38-7753)
