306 



THE PIROPLASMASIDA 



riers (i.e., there is no premunition). In 

 the redefined genus Goiuleria, the forms 

 in the erythrocytes do divide, the para- 

 sites can be transmitted by blood inocula- 

 tion, and recovered animals remain 

 carriers for life (i.e., premunition is 

 present). In the genus Cylaitxzooii, schi- 

 zogony takes place in the histiocytes 

 rather than in the lymphocytes as in the 

 other 2 genera, and the forms in the ery- 

 throcytes reproduce by binary fission. 



Neitz (1959) recognized 1 species of 

 Theileria and 5 of Goiider/a in domestic 

 animals, and 10 named and 36 unnamed 

 species of Theileria, 1 of Gonderia and 2 

 of Cytauxzoon in wild animals. The great 

 majority occur in African ruminants. 

 They are all tabulated by Neitz (1957). 

 Since the forms in the erythrocytes of all 

 3 genera look alike, and since practically 

 all the species in wild animals are known 

 only from these forms, their assignment 

 to the genus Theileria is clearly provi- 

 sional. 



THEILERIA PARVA 



(THEILER, 1904) BETTENCOURT, 



FRANCA AND BORGES, 1907 



Synonyms : Piroplasma kochi, Piro- 

 plasiiia panitui . Theileria kochi. 



Disease : East Coast fever, bovine 

 theileriosis, African Coast fever, Rho- 

 desian tick fever, Rhodesian redwater. 



Hosts : Ox, zebu, water buffalo, 

 African buffalo {Syncerus coffer). 



Location : Lymphocytes, erythro- 

 cytes. 



Geographic Distribution : East, Cen- 

 tral and South Africa. 



Prevalence : East Coast fever is one 

 of the most important cattle diseases in the 

 regions where it is found. According to 

 Neitz (1959), it occurs enzootically in the 

 Belgian Congo, Uganda, Kenya, Tangan- 

 yika, Nyasaland, Zanzibar and Swaziland. 

 It has been eliminated from most parts of 

 South Africa. 



Morphology : The forms in the ery- 

 throcytes are predominantly (over 80%) 

 rod-shaped, and measure about 1. 5 to 

 2.0 by 0.5 to I.Ojlx. Round, oval and 

 comma-shaped forms also occur. When 

 stained with a Romanowsky stain, they 

 have a red nucleus at one end and blue 

 cytoplasm. Several parasites are often 

 found in a single host erythrocyte. 



Fig. 35. Theileria parra in bovine eryth- 

 rocytes. X 2800. (After Nuttall, 

 1913 in Payasilology. published 

 by Cambridge Univ. Press). 



Genus THEILERIA Bettencourt, 

 Franca and Borges, 1907 



In this genus the parasites multiply 

 by schizogony (or possibly by a series of 

 binary fissions) in the lymphocytes and 

 finally invade the erythrocytes. The 

 forms in the erythrocytes do not reproduce. 

 Infection cannot be transmitted by blood 

 inoculation, and there is no premunition. 

 There is one valid species in domestic 

 animals. 



The multiplying forms occur in the 

 lymphocytes and occasionally in the endo- 

 thelial cells. They are found especially 

 in the lymph nodes and spleen, where they 

 are usually very numerous. They are 

 known as Koch's blue bodies or Koch's 

 bodies, and are circular or irregularly 

 shaped bodies averaging 8 /i in diameter 

 and ranging up to 12 jn or more. They 

 may be intracellular or free in the gland 

 or spleen juice. When stained with a 

 Romanowsky stain, their cytoplasm is blue 

 and they contain a varying number of red 

 chromatin granules. 



Two types of these schizonts are rec- 

 ognized. Macroschizonts (sometimes 



