East Coast fever

Definition

A lethal theileriosis of cattle caused by the apicomplexan parasite Theileria parva, transmitted primarily by the brown ear tick Rhipicephalus appendiculatus. The parasite undergoes schizogony in lymphocytes and piroplasm development in erythrocytes, producing fever, lymphadenopathy, pulmonary edema, and high mortality in susceptible Bos taurus and Bos indicus breeds. Endemic to eastern, central, and southern Africa, the disease represents a major constraint to livestock production and is a classic example of tick-borne hemoparasite ecology.

Etymology

Named for the East African coast where the disease was first recognized among cattle imported to southern Africa in the early 1900s.

Example

In Kenyan smallholder systems, Rhipicephalus appendiculatus nymphs acquire T. parva while feeding on infected cattle; the parasite persists through tick molting, and transmission occurs when infected nymphs or adults feed on naïve animals, triggering East Coast fever within 10–25 days.

Synonyms

• Theileriosis
• T. parva infection
• coastal fever

Related Terms

• Rhipicephalus appendiculatus
• Theileria parva
• tick-borne disease
• apicomplexan
• vector-borne parasite
• bovine hemoparasite
• Epizootiology

Usage Notes

The term is sometimes used loosely for any T. parva infection, but properly denotes the acute, lymphoproliferative disease form in cattle; 'theileriosis' is broader, encompassing milder T. mutans and T. annulata infections. 'Coastal fever' appears in older literature. The disease has been eradicated from South Africa through intensive tick control and movement restrictions, demonstrating the feasibility of vector-targeted intervention.