Malignant Ovine Theileriosis (Theileria lestoquardi): A Review

Malignant Ovine Theileriosis (MOT) is a tick borne disease of sheep and goats, caused by Theileria lestoquardi and is considered a major constraint for sheep production in many areas of the world. It has been reported to infect lymphocytes in vivo and in vitro and the schizonts differentiate into macro-schizonts and micro-schizonts. To date, little is known about the mechanisms involved in the disease pathogenesis, but its high mortality is likely to be linked to the ability of T. lestoquardi to stimulate uncontrolled proliferation of the infected leukocyte. Consequently, severe tissue destruction and pulmonary oedema leading to respiratory failure are thought to be the cause of death. Despite an immense amount of small ruminant research, MOT remains an important disease of sheep and goats. Therefore, the present review outlines the current knowledge covering T. lestoquardi transmission, distribution, pathogenesis, diagnosis and control. The information may assist in filling the gaps in our knowledge about the economic impact of the disease and new research initiatives. We conclude that the development of a simple, affordable and applicable diagnostic test for an early detection at the field level, and the production of an effective vaccine could have a significant impact on the control of the disease.