62 



THE HEMOFLAGELLATES 



A complement fixation test, the 

 Machado reaction, has been used, but it is 

 also positive in Leislunaitia infections and 

 weakly positive in a number of other con- 

 ditions. Other serologic tests which have 

 been used are the precipitin reaction, an 

 intradermal skin test and a slide agglu- 

 tination test. T. cruzi can be differenti- 

 ated from the non-pathogenic T. rmigeli 

 by its smaller size and large kinetoplast. 



Treatment : No satisfactory drug is 

 known for the treatment of T. criizi infec- 

 tions, altho Bayer 7602 Ac is used. 



Control : Prevention of human T. 

 cruzi infection depends upon eliminating 

 triatomids from houses. This will also 

 largely prevent infections among domestic 

 dogs and cats. Dusting or spraying houses 

 with residual lindane or dieldrin has given 

 good results. 



TR YPANOSOMA RANGELI 

 TEJERA, 1920 



Synonyms : Tr\'pa>ioso))ia guaterna- 

 lense, T. ariarii. 



T. yaiigeli was first found in the tri- 

 atomid, Rhodnius prolixus, in Venezuela. 

 It was later found in children in Guatemala 

 and still later in Colombia, Chile and El 

 Salvador. It is quite common in dogs, 

 cats and man in certain areas of Venezuela, 

 Colombia and Guatemala, and is sometimes 

 found in mixed infections with T. cruzi. 

 Groot, Renjifo and Uribe (1951) found it in 

 67 of 183 persons in the Ariari Valley and 

 Groot (1951) found it in 1 of 30 persons, 2 

 of 27 dogs and an opossum in the Mira- 

 flores region of Colombia. It has also been 

 found in the monkey, Cebiis fatiiellns. 

 Young mice, rats and rhesus monkeys can 

 be infected experimentally. 



The trypanosomes in the blood are 

 considerably larger than T. cruzi, being 

 26 to 36 )i long. The nucleus is anterior 

 to the middle of the body, the undulating 

 membrane is rippled and the kinetoplast 

 is small and subterminal. 



The most common vector is Rhodnius 

 prolixus, but Triatoma dimidiata and other 



triatomids have also been found infected. 

 A piriform stage about 1 ji long has been 

 found in the foregut, and crithidial and 

 metacyclic trypanosome forms develop in 

 the hindgut. The crithidial stages may be 

 extremely long, ranging from 32 to 70 or 

 even over 100 /i in length. The metacyclic 

 trypanosome forms have a well-developed 

 undulating membrane and a long free fla- 

 gellum. They may pass into the hemolyniph 

 and thence to the salivary glands. They 

 can be transmitted either by bite or by 

 fecal contamination. 



T. rangeli does not appear to be path- 

 ogenic for vertebrates, but Grewal (1957) 

 found that it was pathogenic for R. prolixus 

 and also for experimentally infected bed- 

 bugs. 



The blood forms of T. ra)igeli can be 

 readily differentiated from those of T. 

 cruzi by their larger size and their much 

 smaller kinetoplast. The forms in the in- 

 sect hosts can be distinguished by their 

 small kinetoplast and giant crithidial forms. 



T. rangeli can be easily cultivated in 

 a modified NNN medium containing glucose, 

 peptone and macerated meat (Pifano, 1948). 

 The culture forms are similar to those in 

 the triatomid intestine. For further infor- 

 mation regarding this species, see Groot, 

 Renjifo and Uribe (1951), Groot (1954), 

 Pifano (1948, 1954) and Zeledon (1954). 



TR YPANOSOMA 

 LAVERAN, 1902 



THEILERI 



Synonyms : Trypanosoma franki, 

 T. ivrublewskii, T. himalayanum, T. 

 indiciim, T. muktesari, T. falsliaici, T. 

 scheini, T. americanum, T. rulherfordi. 



T. theileri occurs in the blood of cat- 

 tle. It is worldwide in distribution. It is 

 probably quite common, but is rarely found 

 in blood smears. Crawley (1912) found it 

 in blood cultures from 74% of 27 cattle 

 around Washington, D. C. and Glaser (1922) 

 found it in blood cultures from 25% of 28 

 New Jersey cattle. Neither found it in 

 direct blood smears. Atchley (1951) found 

 it in the blood of 1% of 500 South Carolina 

 cattle. 



