352 SANITARY ENTOMOLOGY 



ANIMAL OKGANISMS TRANSMITTED BY FLEAS 



Protozoa 

 Mastigophora: Bmucleata: TrypanosomiSce 



As stated elsewhere the classification here used was recently proposed 

 by Chalmers. It is especially interesting that all flea-borne diseases 

 belong to the genus Trypanozoon Luhe {Lewisonella Chalmers)^ in 

 which the final stage of development in the definitive host (the insect) 

 occurs in the hind gut, and infection is contaminative. 



Trypanozoon blanchardi (Brumpt), cause of a trypanosomiasis, sup- 

 posedly nonpathogenic, in rodents of the genera Myoxus and Microtus 

 has been found by Brumpt (1913) to develop in the flea, Ceratophyllus 

 laverani Laveran and Pettit. The life cycle is identical with that of T. 

 lewisi and T. nabiasi and is effected entirely in the large intestine of the 

 flea. Metacyclic trypanosomes occur in the rectal ampulla and are found 

 in the dejections. It is not found in the salivary glands. 



Trypanozoon duttoni (Thiroux), cause of a trypanosomiasis, sup- 

 posedly nonpathogenic, in mice of the genus Mus, has been found by 

 Brumpt (1913) to develop in the flea, Ceratophyllus hirundinis Curtis. 

 The evolution of this species occurs in the large intestine of the flea and 

 is comparable to that of T. lewisi, T. nabiasi, and T. blanchardi. It is 

 not found in the salivary glands. 



Trypanozoon lewisi (Kent), cause of a trypanosomiasis, rarely patho- 

 genic, in rodents of the genera Epimys, Acanthomys, Mus, Myoxus, and 

 Meriones, etc., passes its cycle of sporogony in fleas (fig. 62). The life 

 cycle has been investigated in Ceratophyllus fasciatus (Bosc) Curtis, 

 Ctenocephalus canis (Curtis) Baker, and Ctenopsyllus musculi (Duges) 

 Wagner, and it has been shown that Pulex irritans Linnaeus, and 

 Xenopsylla cheopis Rothschild may serve as true hosts. In addition 

 Ceratophyllus lucifer Rothschild, C. hirundinis Curtis, Ctenophthalmus 

 agyrtes (Heller) Baker, and Pidex brasiliensis Baker are recorded as 

 carriers. Fantham, Stephens and Theobald summarize the life cycle 

 in the flea. When infected blood is taken up by the flea, the parasites 

 pass with the ingested blood direct to the mid-gut of the flea. In the 

 etomach they penetrate the cells of the lining epithelium and multiply 

 by division inside the epithelial cells. They first grow to a large size, then 

 form large spherical bodies within which nuclear multiplication occurs. 

 Any one of these large spherical bodies contains at first a number of nu- 

 clei, kinetonuclei, and developing flageUa, the original flagellum still re- 

 maining attached for a time. The cytoplasm then divides into daughter 

 " This synonymy is according to Mesnil. Bull. Inst. Past. vol. 17, p. 190. 



