312 



THE PIROPLaiSMASIDA 



type. Merozoites have apparently not been 

 seen, but they must occur. 



Life Cycle : The vectors of G. miitans 

 in Africa are Rhipiceplialiis appendiculalus 

 and R. everlsi. In addition, Boophilus 

 annulatus has been found to be able to 

 transmit this species experimentally. 

 Transmission is stage-to-stage. 



The stages in the tick vectors are un- 

 known. 



GONDERIA LAWRENCEI 



(NEITZ, 1955) 



NEITZ AND JANSEN, 1956 



Synonyms : Theileria lawrencei, 

 Gonderia bouts. 



Disease : Corridor disease, buffalo 

 disease, malignant syncerine gonderiosis, 

 Rhodesian malignant bovine gonderiosis. 



Hosts : Cattle, African buffalo {Syn- 

 cerus coffer). The buffalo is the natural 

 host. 



Pathogenesis : G. mutans is seldom 

 more than slightly if at all pathogenic, 

 altho an acute form of the disease may 

 develop in cattle imported into an endemic 

 area and exposed to massive tick infesta- 

 tion. The mortality is less than 1%. 



The signs, course of the disease and 

 lesions resemble those of mild G. anmdata 

 infections. Anemia, if present, is slight. 

 Icterus is sometimes present, and the 

 lymph nodes are moderately swollen. In 

 acute cases the spleen and liver are 

 swollen, the lungs may be edematous, there 

 are characteristic ulcers in the abomasum, 

 and infarcts may be present in the kidneys. 

 Hematuria is absent. 



The incubation period following tick 

 transmission is 10 to 20 days with a mean 

 of 15 days. The disease lasts 3 to 10 days 

 with a mean of 5 days. 



Splenectomy may cause the appearance 

 of parasites in the blood, and indeed Split- 

 ter (1950) first observed them in a splen- 

 ectomized calf. 



Immunity : Animals which have once 

 been infected with G. mutans are premu- 

 nized. There is no cross-immunity be- 

 tween G. mutans and G. annulata, G. 

 lawrencei and T. parva. 



Diagnosis : Same as for other species 

 of Gonderia and Theileria. 



Location : Lymphocytes, erythrocytes. 



Geographic Distribution : Union of 

 South Africa, Southern Rhodesia. 



Prevalence : This disease is widely 

 distributed in Southern Rhodesia, both in 

 cattle and African buffaloes. In the Union 

 of South Africa its distribution is much 

 more restricted, and it occurs only in 

 cattle which have come in contact with 

 ticks from premune African buffaloes. It 

 takes its name from the fact that it was 

 first found here in the Corridor, a stretch 

 of 100 square miles of land between the 

 Hluhluwe and Umfolozi Game Reserves 

 where buffalo abound. It has also been 

 found around Kriiger National Park. 



Morphology : The erythrocytic stages 

 are oval, round, piriform or comma- 

 shaped, and indistinguishable from those 

 of G. mutans. About 55% are round or 

 oval. 



There are relatively few Koch bodies 

 in the lymphocytes of the spleen and lymph 

 nodes or free in these organs. They aver- 

 age 5(i in diameter but may range up to 

 lOjLt. They contain 1 to 16 or 32 reddish 

 purple granules 0. 5 to 2):i in diameter and 

 are practically all of the macroschizont 

 type. The mature macromerozoites are 

 2.0 to 2. 5 fx in diameter, and the mature 

 micromerozoites are 0.7 to 1.0 /i in diam- 

 eter. 



Treatment: None known. 



Prevention and Control : These de- 

 pend upon tick control. 



Life Cycle : The vector is Rhipi- 

 cephalus appendiculalus, and transmission 

 is stage-to-stage. The parasite stages in 

 the tick are unknown. 



