East Coast Fever
East Coast fever is a form of theileriosis caused by Theileria parva.
Mainly cattle. Also possibly buffalo.
Mainly in tropical regions due to reliance upon tick vectors.
Early clinical signs include marked pyrexia, leucopaenia, inappetence, decrease in milk production, lymphadenopathy and palpably hot lymph nodes. As disease progresses, multisystemic signs develop:
Cardiovascular – Tachycardia, Petechiae and Ecchymoses, possibly Anaemia
Respiratory - Nasal discharge, Dyspnoea, Cough
Gastrointestinal – Diarrhoea with mucus and/or blood, Inappetance, Hypomotility, Constipation
Opthalmological – Blindness, Corneal opacity, Discharge, Photophobia, Increased lacrimation
Reproductive – Abortion, Stillbirths, Agalactia
Other – Sudden death, Icterus, Marked Pyrexia, Neurological signs, Emaciation
The clinical phase usually lasts 2-3 weeks, but death occasionally occurs within a week.
Sub-lethal acute disease may be followed by complete recovery or more usually continue as chronic emaciation and decreased productivity and performance.
Acute and usually fatal form of East Coast Fever that occurs when T. parva is transmitted from African buffalo to cattle. Buffalo appear to be asymptomatic carriers.
Also Known As – Zimbabwe theileriosis – Fortuna disease
Acute strictly seasonal fatal form of T. parva in Zimbabwe. Occurs only from December to May, or more commonly January to March, due to the distribution of its vector, Rhipicephalus appendiculatus.
Chronic signs such as emaciation and diarrhoea are rarely seen in Corridor disease and January disease due to the short disease course before death.
On post-mortem examination, the lymphoid system is severely damaged and respiratory changes are marked. Froth is often present in the trachea, bronchi and bronchioles due to pneumonia and pulmonary oedema. Necrosis of the lymphoid tissue may be seen. Lymph nodes and spleen may be hyperplastic. The heart is commonly petechiated and ecchymotic. Petechiae may also be seen throughout the intestines and abomasums in ruminants.
Buparvaquone/Parvaquone and Halofuginone chemotherapy drugs can be effective but their cost often makes them prohibitive.
Tetracyclines may also be effective against schizonts.
Immunisation with cryopreserved sporozoites is also possible but carries a risk of causing patent disease.
Vaccination with cryopreserved sporozoites derived from crushed ticks is possible but expensive and not without risks. Vaccination is followed by treatment with long acting oxytetracycline - the so called Infection and Treatment Method (ITM).
Control of tick vectors and use of tick resistant breeds is also valuable.
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The datasheet was accessed on 2 June 2011.
This article has been expert reviewed by Nick Lyons MA VetMB CertCHP MRCVS
Date reviewed: 25 March 2012
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