984 



ORDER I. RICKETTSIALES 



mized, non-carrier sheep and goat following 

 infection, and (4) animals other than the 

 sheep and goat following infection. Re- 

 covered animals remain carriers for periods 

 of up to four years; the end point has not 

 been determined. 



Serology: No work has been attempted. 



Pathogenicity: Infected blood and organ 

 suspensions produce infection by the sub- 

 cutaneous, intramuscular and intravenous 

 routes. Infectious for sheep, goats and the 

 African antelope, the blesbuck {Damaliscus 

 pygargus albifrons). The eland (Taurotragus 



oryx oryx) develops a submicroscopic infec- 

 tion. Cattle are refractory. No cases of 

 autosterilization have been observed. 



Antibiotic therapy: No tests conducted. 

 Aureomycin and terramycin may possibly 

 be as effective for A. ovis as for A. marginale. 



Source : Observed in the blood of infected 

 sheep and goats. 



Habitat: Found in arthropods such as 

 Rhipicephalus bursa, Dermacentor silvarum 

 and Ornithodoros lahorensis; also found in 

 the erythrocytes of sheep and goats. Found 

 in Africa, Southern Europe and Asia. 



