Theileria
| Theileria | |
|---|---|
| Kinete stage of Theileria parva in the transmitting tick Rhipicephalus appendiculatus | |
| Scientific classification | |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | Sar |
| Clade: | Alveolata |
| Phylum: | Apicomplexa |
| Class: | Aconoidasida |
| Order: | Piroplasmida |
| Family: | Theileriidae |
| Genus: | Theileria |
| Species | |
|
Theileria annulata | |
Theileria is a genus of parasites that belongs to the phylum Apicomplexa, and is closely related to Plasmodium. Two Theileria species, T. annulata and T. parva, are important cattle parasites. T. annulata causes tropical theileriosis and T. parva causes East Coast fever. Theileria species are transmitted by ticks. The genomes of T. orientalis Shintoku, Theileria equi WA, Theileria annulata Ankara and Theileria parva Muguga have been sequenced and published.
Theileria equi infects equid blood cells causing equine piroplasmosis. The disease presents with a variety of clinical conditions, such as fever, depression, jaundice, cramps, haemolytic anaemia, hemoglobinuria and even death, but asymptomatic infections are frequently observed. The most common vectors are the ticks Dermacentor nitens and Rhipicephalus microplus but Amblyomma cajennense was also implicated in the disease transmission.
Vaccines against Theileria are in development. In May 2010, a vaccine that was reported to protect cattle against East Coast fever had been approved and registered by the governments of Kenya, Malawi, and Tanzania.