350 EAST AFRICAN COAST FEVER 
EAST AFRICAN COAST FEVER 
Synonyms: East Coast fever; Rhodesian red water; Rhodesian 
tick fever. 
Characterization. This is a disease of cattle characterized by the 
presence of a piroplasma. It is distinguished from the other piro- 
plasmoses of cattle in that it cannot be transmitted from one animal 
to another by the direct inoculation of the blood. 
History. This disease was differentiated from the other piroplas- 
mic diseases by the investigations of Theiler in the Transvaal and 
Koch and Buluwayo. In 1905, it is stated that 500 farms in the Trans- 
vaal were infected and that within a year 50,000 cattle had died of it. 
Geographical distribution. This disease seems to be restricted to 
the Eastern coast of Africa. In 1900 it was introduced into the 
Portuguese territory from whence it spread into the interior of Africa, 
especially to the German East Africa, Natal, the Transvaal and 
Rhodesia. 
Etiology. This disease is caused by Piroplasma (Theileria)* 
parvum. 
It is transmitted by the ticks (R. appendiculatus and R. simus and 
possibly other species of the same genus. In the blood of infected 
cattle three forms of the blood parasite are found. In the acute form 
of the disease the parasites assume a ring or bacillary form and not 
infrequently the one may be seen to change into the other; they exhi- 
bit amceboid movement, and a small mass of chromatin can be made 
out. In the chronic form of the disease the parasite appears as a non- 
motile punctiform mass of chromatin. It is stated that the parasites 
are very abundant in the blood. In the acute form as many as 90% 
of the red blood corpuscles are affected. It is also stated that P. 
mutans is often present in the blood of animals suffering from this 
infection. As already stated, the disease cannot be produced arti- 
ficially by the inoculation of the blood containing the parasite. 
Meyer obtained positive results by introducing large pieces of spleen 
*Franca points out that Bettencourt and Borges proposed that the genus Piroplasma 
should include only those organisms which at one stage are pear shaped—twin parasites 
appearing in the single corpuscle and which multiply by budding as described by 
Nuttall. The characteristic features of the two genera suggested are as follows: 
Genus Theileria Bettencourt, Franga and Borges, 1907. Rod-like parasites which when 
dividing give rise to cross-forms. The individual elements of the cross-forms are very 
small, rounded, and composed, practically, exclusively of chromatin. 
Genus Nuttallia, Franga, 1909. Parasites oval or pyriform, No rod-like bodies. 
Cross multiplication, the protoplasm of these forms being relatively abundant. 
