THE PIROPLASMASIDA 



29S 



Morphology: Same as B. bovis. 



Life Cycle : Same as B. bovis. The 

 vectors in North Africa are Boophilus 

 calcaratus and Rliipicephalus bursa. 

 Transmission occurs thru the egg in the 

 former and stage-to-stage in the latter. 

 The vector in the USSR is Ixodes ricinus. 



Pathogenesis: Same as B. bovis. 



Treatment: Same as B. bovis. 



Remarks : As mentioned above, B. 

 berbera is probably a synonym of B. bovis. 



BABESIA DIVERGENS 



(M'FADYEAN AND STOCKMAN, 1911) 



Synonym: Piroplasma divergens. 



Hosts: Cattle, rarely man. 



Location: Erythrocytes. 



Geographic Distribution : Western 

 and central Europe. 



Prevalence : This is probably the 

 commonest if not the only species of 

 Babesia in western and central Europe, 

 but further investigation is needed to con- 

 firm this statement. B. divergens is now 

 definitely known to occur in Yugoslavia, 

 Austria and England (Simitch, Petrovitch 

 and Rakovec, 1955; Davies, Joyner and 

 Kendall, 1958). 



Morphology : This species is smaller 

 than B. bovis. The trophozoites usually 

 occur as paired, club-shaped organisms 

 about 1. 5 by 0. 4 jj. ; the angle between the 

 members of the pair is relatively large, 

 so that they diverge more from each other 

 than the trophozoites of B. bovis; in addi- 

 tion, they tend to lie along the circumfer- 

 ence of the host erythrocyte (the so-called 

 accole' position). Other trophozoites are 

 stouter and piriform (about 2 by 1 |u ), cir- 

 cular (about 1.5)M in diameter), or vacu- 

 olated and circular (up to 2|u in diameter) 

 (Davies, Joyner and Kendall, 1958). 



Life Cycle : Same as that of B. 

 The vector tick is Ixodes ricinus. 



bovis. 



Pathogenesis: Same as for B. bovis. 



Immunity: Same as for B. bovis. 



Diagnosis: Same as for B. bovis. 



Treatment: Same as for B. bovis. 

 Amicarbalide was found by Beveridge, 

 Thwaite and Shepherd (1960) and Lucas 

 (1960) to be effective against 5. divergens. 

 The dosage is about 5 to 20 mg per kg 

 subcutaneously or intramuscularly. 



Remarks : Skrabalo and Deanovic 

 (1957) described a fatal human case of 

 babesiosis accompanied by blackwater due 

 to B. divergens in Yugoslavia. The pa- 

 tient had had a splenectomy 11 years be- 

 fore and lived on a tick-infested farm 

 where the cattle had babesiosis. 



Garnham and Bray (1959) infected 2 

 splenectomized chimpanzees and a splen- 

 ectomized rhesus monkey with the British 

 strain of B. divergens described by Davies, 

 Joyner and Kendall (1958), but were unable 

 to infect 2 splenectomized rabbits. The 

 parasites in the rhesus monkey had the 

 typical accole' form, but those in the 

 chimpanzees did not. Garnham and Bray 

 suggested that latent babesiosis might 

 exist in man on a large scale in rural pop- 

 ulations in infected regions. 



BABESIA ARGENTINA 

 (LIGNIERES, 1903) 



Synonyms: Piroplasma argentinum, 

 Fra)icaiella argentina. 



Hosts : Cattle. 



Location: Erythrocytes. 



Geographic Distribution : South 

 America, Central America, Australia. 



Morphology: The trophozoites re- 

 semble those of B. bovis. They are 

 piriform, about 2.0 by 1. 5jx, and usually 

 lie in the center of the host erythrocyte. 



Life Cycle : Similar to that of B. 

 bovis. The vector in South America is 

 Boophilus microplus and that in Australia 



