59 



Host of the Piroplasm. 



Numerous experiments (Theiler) (Lounsbury) have established the 

 fact that the transmission of the parasites which invade the erythrocytes 

 in East Coast fever takes place by the agency of ticks. From the most 

 recent experiments it has been shown that Rhipicephalus appendiculatus 

 is the principal transmittor ; the affection being carried by nymphae 

 and adults, that Rt. evertsi, Rt. capensis, Rh. simus, and Rh. nttens are 

 hosts of Theileria parva. Although the present knowledge with regard 

 to the means of transmission of Babesia mutans is perhaps still incomplete, 

 recent observations (Theiler *) point to Rh. appendiculatus and Rh. evertsi 

 as being hosts. 



Cmirse, Symptoms, and Pathological Lesions. 



The incubative period of East Coast fever averages twelve days, 

 variations being ten clays shortest and twenty days longest period ; 

 following this a sudden rise of temperature occurs in the majority of cases, 

 reaching 106-107 and remaining high throughout. In a few cases the 

 temperature rises gradually day by day, until the maximum is reached. 



The fever period averages about thirteen days, variations being 

 six days minimum and twenty days maximum. Consequently the length 

 of the disease from date of infection averages twenty-five days. 



The symptoms during life are not always characteristic ; they are 

 subordinate to the seat of lesions. In some instances the animal may 

 appear in normal health up till the time of death, and in such is usually 

 foand dead with a discharge of foam from the nostrils, resulting from an 

 oedematous condition of the lungs. In other cases in which the oedema 

 of the lung, although present, is not so pronounced as to cause immediate 

 death pulmonary symptoms, such as coughing and discharge from 

 nostrils, may be noticed. Where bowel lesions are present diarrhoea or 

 a haemorrhagic discharge may be present; depending on their severity, 

 swelling of the lymphatic glands of the head and throat may be detected 

 in a number of cases. Frequently the first symptoms observed will be 

 a discharge from nose and eyes and increased flow of saliva from the 

 mouth, or simply a loss of condition. Haemoglobinurea is not a symptom 

 of the disease, but is the expression of the complication with ordinary 

 redwater (Texas fever). Where the disease is associated with ordinary 

 redwater, as frequently happens in a country in which that disease is 

 known to exist, symptoms of redwater overmask those of East Coast 

 fever. 



The post-mortem lesions vary. The organs found most constantly 

 affected are the spleen, liver, kidney, and heart. Lung lesions are 

 present in from 30-35 per cent, of cases (Gray).t 



* Transvaal Biological Society Proceedings, 29/3/09. 



t East Coast Fever — A Historical Review : Annual Report of the S. A. Association for the Advancement 

 of Science, Grahamstowii meeting, 1908. 



