28 



Archibald (R. G.). A Preliminary Report on Some Further Investiga- 

 tions on Kala-Azar in the Sudan. — Jl. R. Army Med. Corps, 

 London, xxiii, no. 5, November 1914, pp. 479-495. 



After a description of the results of some laboratory investigations 

 on transmission, a number of facts against the theory that kala-azar 

 is conveyed by biting insects, are detailed. In the Sudan, this disease 

 is extremely uncommon among the female population, though the 

 customs of" the native women would certainly expose them more 

 readily to the attacks of such biting insects as bed-bugs, fleas, lice and 

 mosquitos, which are to be found in the dark huts which are usually 

 occupied all day by the female element of the population. Their 

 beds also are usually heavily infested with C. lectularius. 



•As a rule, only a single individual is attacked, the other members 

 of the family occupying the same huts showing no signs of the disease. 

 Such animals as dogs, cats, goats, sheep, hens and pigeons, which are 

 also frequent occupants of these huts, have never been found infected. 

 It is difficult to associate this fact with the theory that the disease is 

 transmitted by a biting insect, particularly in view of the evidence 

 brought forward by Marshall, who found that the parasite was present 

 in the peripheral blood in 86-6 per cent, of kala-azar cases, and by 

 Wenyon, who successfully cultivated the parasite from the peripheral 

 blood. 



Since the disease has been investigated in the Sudan, it has not 

 been found in an epidf mic form, which is contrary to what occurs in 

 most diseases transmitted by biting insects. 



In the course of experimental researches, there has been no evidence 

 to show the existence or development of the Leishmania parasite in 

 bed-bugs, lice, and fleas fed on cases of kala-azar in the Sudan, and 

 attempts to transmit the disease to susceptible animals by means of 

 previously fed bed-bugs and lice have failed. Marshall also obtained 

 negative results in his transmission experiments with the dog flea, 

 Ctenocephalus canis. 



Although the experiments illustrating the destructive action of 

 human blood serum on cultures of Leishmania were carried out in 

 vitro, they appeared to furnish presumptive evidence against the 

 possibihty of the cultural forms of Leishmania living after entering 

 the human host via the skin. 



Attempts to infect a susceptible animal, the monkey, Lasiopyga 

 callitricha, by vaccinating it with a heavily infected culture of Leish- 

 mania failed. 



The successful results obtained by feeding two animals with infected 

 material, afford ground for suspecting a similar mode of infection in 

 man, possibly through drinking water. The disease is more common 

 in villages near the rivers, though cases also occur in villages inland, 

 in which the wells dry up in summer. If water-borne, the disease 

 should be more prevalent in the endemic areas ; possibly some 

 lesion of the intestinal tract is necessary, in order that the infecting 

 organism may find an entrance. 



