LEISHMANIA TROPICA 431 



DIRECT INOCULATION FROM MAN TO MAN.— Before the discovery 

 of L. tropica, it was well known that oriental sore could be handed on from 

 man to man by inoculation of the skin with the material from a sore. In 

 some places, such as Bagdad, Mosul, etc., it was the custom to inoculate 

 on the arm or some covered part of the body, with a view to developing 

 an immunity which would prevent the disfigurement of a natural infection 

 on the face. One attack of the disease as a rule confers an immunity 

 which lasts for the rest of life. 



Definite evidence of the transference of the parasite in this way was 

 first produced by Marzinowsky (1909), who inoculated himself. Parasites 

 were demonstrated in the sore, which was first visible seventy days after 

 inoculation. Nicolle and Manceaux (1910a) obtained a positive result 

 by inoculation of cultures by scarification of the skin. The writer (1912a) 

 inoculated himself in a similar manner with material from a sore in 

 Aleppo. After a preliminary suppuration the wound healed, and it was 

 not till nearly seven months later that a minute red speck appeared at 

 the site of inoculation. This increased in size, and L. tropica was con- 

 stantly present for one and a half years, during which it persisted. 



Patton (1912) inoculated himself and developed a sore after sixteen 

 days. Bouilliez (1917) inoculated himself accidentally. Material from a 

 syringe entered the conjunctival sac, and about four months later a papule 

 appeared on the internal surface of the lower lid. It increased in size to 

 that of an almond, and a second papule appeared. L. tropica was demon- 

 strated in the lesions. It is possible, therefore, for the parasite to infect 

 a healthy mucous membrane. It does not appear to be able to pass 

 the healthy skin, as was demonstrated by the writer. Material from a 

 sore was placed on the healthy skin and allowed to dry naturally, but no 

 sore developed at this spot, though at another spot where the skin was 

 scarified a typical lesion resulted. 



These experiments of direct inoculation have their parallels in natural 

 infections. Numerous records occur of individuals who have developed 

 oriental sore at the site of some accidental wound or abrasion of the skin. 

 It is also well known that a person with one sore may auto-infect himself 

 by scratching on other parts of the body. 



SUSCEPTIBILITY OF ANIMALS.— It was first demonstrated by Nicolle 

 and Manceaux (1910) tliat dogs could be inoculated in the skin with 

 L. tropica, and that local cutaneous lesions containing the parasites resulted. 

 Since then a number of observers have shown that dogs, cats, monkeys, 

 rats, mice, and guinea-pigs can be similarly inoculated. In the case of 

 small mammals such as mice, intraperitoneal inoculation has resulted in 

 generalized infections, resembling in many respects those produced by the 

 inoculation of L. donovani. 



