PROTOZOAN PARASITES OF MONKEYS AND MAN 



2-37 



iense) have not been reported from mon- 

 keys. The only natural infections thus 

 far discovered have been in dogs and cats. 

 Laboratory monkeys can be infected by 

 the injection of large doses of L. dotiovani 

 grown in culture, but the virus loses its 

 virulence when passed through a succes- 

 sion of animals and finally becomes non- 

 infective. Monkeys may die after several 

 months as a result of infection with 

 L. donovani, or may suffer a chronic 



MALARIAL PARASITES OF MONKEYS AND MAN 



Malarial parasites were first found in 

 monkeys by Koch in 1898. During the 

 following year Laveran, the discoverer 

 of the malarial parasites of man, dis- 

 covered similar organisms in Cercopithecus 

 sabaeus, to which he gave the specific 

 name kochi. Since then malarial para- 

 sites (figs. 14-19) have been reported from 

 the chimpanzee, gorilla, orang, baboon, 



Malarial Parasites of Monkeys 



Fig. 14. Plasmodium inui. Ring stage in red blood corpuscle. 

 Fig. 15. P. brasilianum. Young trophozoite. 

 Fig. 16. P. kochi. Older trophozoite (schizont). 

 Fig. 17. P. inui. Segmentation stage (schizogony). 

 Fig. 18. P. malariae. Band-like stage of trophozoite. 

 Fig. 19. P. reicbenowi. Crescent-shaped gametocyte. 



All figures drawn at a magnification of about xooo diameters. (From Wenyon. Figs. 14 and 17 after Mathis 

 and Leger; figs. 15 and 16 after Gonder and Gossler; figs. 18 and 19 after Reichenow.) 



infection and recover. In some monkeys, 

 as Row (191Z), Korke (1914), and Tyzzer 

 and Walker (1919) have shown, cutaneous 

 inoculation with kala-azar material results 

 in skin lesions and not in generalized 

 infections. Monkeys are also susceptible 

 to infection with both L. tropica (Nicolle 

 and Sicre, 1908) and L. braziliense (Wenyon, 

 1913). The organisms bring about the 

 production of lesions that resemble those 

 in man, but disappear sooner. 



and over a dozen other species of Old 

 World and New World monkeys. At 

 least eight new species have been described, 

 but how many of these are "good" species 

 is still to be determined. Of particular 

 interest is the fact that certain of these 

 parasites in monkeys resemble so closely 

 the three species that occur in man that 

 they are morphologically indistinguish- 

 able. Thus Plasmodium kochi (fig. 16) is 

 similar to P. vivax, the tertian parasite of 



