392 FAMILY: TRYPANOSOMID^ 



INOCULATION OF INSECT TRYPANOSOMID^ INTO VERTEBRATES. 



A number of investigators, particularly Laveran and Franchini, and 

 Fantham and Porter, have claimed that vertebrates, particularly mice, 

 may be infected easily with insect flagellates by inoculation or feeding. 

 In some cases it is stated that a definite disease condition resembling 

 kala azar has resulted, and that the infection can be handed on from 

 animal to animal by inoculating emulsions of the infected organs. The 

 infection is associated with the presence of leishmania forms in smears of 

 the organs, while sometimes actual leptomonas forms occur in the blood. 

 The experiments of these investigators have been repeated by a number 

 of competent observers, who have failed entirely to substantiate their 

 claims. It would seem probable that some fallacy, such as the interpre- 

 tation as leishmania of structures which are of another nature, has been 

 responsible for the very high percentage of positive results claimed. The 

 only reliable test of an infection is the discovery of undoubted parasites in 

 smears of the blood or organs, or the development of flagellates in cultures 

 made from the blood or organs on N.N.N, or other suitable medium. 



After Basile's claim that Mediterranean kala azar was transmitted from dog to 

 man by the dog and human fleas, Ctenocephalus canis and Pulex irritans, had become 

 known, the relation of the naturally occurring flea flagellates to Leishmania donovani 

 became the subject of many investigations. The question was raised as to whether 

 the insect flageUates could give rise to infections when inoculated into vertebrates. 

 Laveran and Franchini (1913) published an account of the infection of mice with 

 Leptomonas ctenocejjhaU. After inoculation by the intraperitoneal route, the para- 

 sites were found by direct examination in the peritoneal exudate and in the blood 

 for as long as sixty days. In the blood, both leishmania and leptomonas forms 

 occurred, while after death leishmania forms were found in the smears of liver and 

 spleen. Mice inoculated with peritoneal exudate of inoculated mice also acquired 

 an infection. Later (1914a, 1919, 1920) su.ccessful infections of mice, rats, guinea- 

 pigs, dogs, and monkeys {Macacus cynomolgus) were reported. Mice were readily 

 infected by inoculation of emulsions of the organs of infected mice, while rats were 

 infected by inocidation with heart blood, and dogs with spleen emulsion of infected 

 mice. Again, in other papers (1914&, 1914c, 1919a) it is recorded that, working 

 with L.pattoni of Ceratophyllus fasciaius, rats and mice were found to be susceptible 

 to inoculation and feeding. Eats and mice placed in jars with infected fleas for 

 forty-eight hours became infected with L. pattoni, and it was shown that mice could 

 be infected by contaminating their food with infected fleas. Mice were also infected 

 by the oral administration of Orithidia melopliagia {Trypanosoma melopliagium). 

 Experiments (1913a, 1914a) were also carried out with rats and mice and Crithidia 

 fasciculata of Ano2^1ieles maculipennis with similar residts. This flagellate was also 

 inoculated from one mouse to another, and an interesting result was obtained by 

 cutaneous injection. A local sore developed, in which leishmania forms were said 

 to occur.' There was also a general infection at the same time. Galli- Valeric (1923) 

 also states that more than two months after inoculation of a rat with the flagellates 

 from MeJophagus ovinus the animal died, and leishmania forms were found in its organs. 



