A. persicm 89 



the liver swollen with more or less fatty degeneration, at times the liver 

 is dotted with focal necroses. In chronic cases both of these organs 

 may appear atrophied. The blood is fluid and dark. Spirochaetes are 

 plentiful in the blood until shortly before death, and they disappear as 

 recovery sets in. 



This disease is transmitted by Argas persicus (= miniatus), as was 

 proved by Marchoux and Salimbeni. By means of infected Argas 

 persicus sent to one of us (N.) in England by Drs Marchoux and Borrel, 

 of Paris, the disease was reproduced in fowls at Cambridge. Balfour 

 (1907) has observed the same disease in Anglo- Egyptian Soudan, and 

 has also transmitted it by means of infected A. persicus. Blood films 

 or infected ticks or both have been received from Dr Balfour (Khartoum), 

 Dr Bitter (Cairo), Captain Greig, I.M.S. (Punjab, India), and Dr Johnson 

 (Adelaide, S. Australia), from which it appears that the disease is very 

 widely distributed. Reaney (1907) has observed spirochaetosis in fowls 

 at Agar-Malwa, Central India, and also records the presence there of 

 persicus. He demonstrated that the ticks conveyed the disease. 

 Marchoux and Salimbeni (1903) and Borrel and Marchoux (1905) 

 found that when A. persicus sucks blood containing Sp. marchouxi 

 the latter multiplies within the body of the tick (maintained at 

 30 — 35° C.) and it is capable of transmitting the disease for 6 months 

 or more afterwards if it bites a susceptible animal. When the ticks are 

 maintained at 15 — 20° C. after feeding upon infected blood they are not 

 capable of transmitting the spirochaetes to clean fowls. The spirochaetes 

 seem to disappear in ticks kept at a low temperature, but they reappear 

 if the ticks are placed at 30 — 35° C. although a period of 3 months may 

 have elapsed since the ticks fed upon infected blood. The spirochaetes 

 may be demonstrated in the coelomic fluid of the infected ticks by 

 cutting off a leg and collecting the fluid on a slide. The spirochaetes 

 do not appear to injure the ticks. The disease usually breaks out 4 — 5 

 days after the ticks bite the birds. 



Spirochaetosis in Geese was observed in the Transcaucasus by 

 Sakharoff (1891), of Tiflis. The disease is as fatal as Spirochaetosis 

 in fowls, and it is probable that it is transmitted by A. persicus, 

 since this tick occurs in Southern Russia. 



Note: Proof is still lacking that A. persicus plays a part in human 

 pathology as a carrier of infection, or that the fever attributed to its 

 bite in Persia is relapsing fever. Manson (1908, p. 196) states that 

 " miana fever " is " certainly communicated " by A. persicus, but there is 

 no scientific evidence in support of the statement. 



