TREATMENT OP TRYPANOSOMIASIS. 23 



II. TREATMENT WITH ANILINE AND OTHER DYES. 



The treatment of trypanosomiasis with the aniline colors was intro- 

 duced by Ehrlieh, who first employed coloring matters belonging to the 

 benzopurpurin group for this purpose. A substance (trypan red) was 

 discovered which was found to possess marked trypanocidal properties. 

 Since this discovery considerable attention has been given by numerous 

 observers to the study of the value of other coal-tar dyes belonging to 

 the benzidine (diazo) group, to the triphenyl methane, and to the afridol 

 colors. 



However, very extensive experiments have shown that while the sub- 

 cutaneous injections of trypan red, trypan blue, brilliant green, malachite 

 green, parafuchsin and a few other dyes, into small animals, such as 

 mice and rats, can sometimes permanently free them from trypanosomata, 

 larger animals can not be cured by these drugs. Koch treated a num- 

 ber of patients suffering from sleeping sickness in Africa with trypan 

 red but obtained such unsatisfactory results that he soon discontinued 

 the use of the drug. The administration of the dyestuffs by mouth to 

 experimentally infected animals has given even less satisfactory results 

 than the subcutaneous injections. It is true that Ehrlieh was successful 

 in preventing subsequent infection in mice after feeding them para- 

 fuchsin and that this work was confirmed by Browning. However, 

 recently Breinl and Nierenstein were unable to obtain any favorable 

 results by such a method in large animals. Two horses were fed on 

 parafuchsin; one received 15 grams daily by mouth for thirty days and 

 died after having shown toxic symptoms from the parafuchsin; the 

 second horse received 15 grams by mouth for forty-eight days. On 

 inoculation it became infected in the same manner as an untreated 

 animal. In our opinion the aniline dyes thus far experimented with 

 are of practically no value in the treatment of sleeping sickness in man, 

 or of trypanosomiasis in the larger domestic animals. This field of 

 treatment seems at the present time practically to be abandoned. 



III. TREATMENT WITH COMPOUNDS OF ARSENIC. 



It appears that Livingston and Braid, as long ago as 1858, first 

 suggested the use of arsenic for the treatment of horses infected with the 

 bite of the tsetse fly. 



Lingard, in 1893, and Bruce, in 1S94, also employed arsenic as a curative and 

 prophylactic agent for surra and nagana respectively. 



Laveran and Mesnil, in 1902, performed extensive experiments with several 

 arsenical compounds, obtaining the best results with sodium arsenate. With 

 this drug they were able to cause the parasite to disappear from the blood. 

 While the lives of the animals were considerably prolonged, a permanent cure 

 was not effected. Similar results were obtained in the treatment, by arsenic, 

 of horses afflicted with surra in the Philippines by Curry, Musgrave and one of 

 us in 1902 and 1903. Moore, Chichester, Thomas, and Breinl also performed 

 extensive experiments with arsenic and sodium arsenate. 



