Introduction East Coast Fever (ECF), caused by the haemoprotozoan parasite Theileria parva and transmitted by ticks, causes considerable economic losses in 11 countries in Eastern, Southern and Central Africa. With about half of this region's 75 million cattle being at risk of ECF (1), losses caused by this disease are considerable, but quantitative assessments vary widely. For instance, in Tanzania the estimates of annual production losses due to ECF range from US$ 43 million [(2), cited by Ref.