2 The Philippine Journal of Science mi 



with this protozoon are likely sooner or later to develop balan- 

 tidial dysentery; that, once the dysenteric condition is estab- 

 lished, it is apt to run a fatal course; and in that no efficient 

 treatment is known for this disease. 



Various drugs and chemicals given by mouth or used as 

 enemata have been employed in the treatment of balantidial 

 infections. Authors have reported the disappearance of the 

 balantidia from the stools and the improvement of their patient 

 following treatment with certain of these substances; but the 

 specific therapeutic action of them has in each case been ren- 

 dered doubtful by the fact that other authors have found the 

 same treatments worthless. The explanation of these incon- 

 sistent results is to be found in the latency characteristic of 

 the disease and in the tendency of the parasites to disappear 

 spontaneously from the stools of infected persons for variable 

 lengths of time. As a result of these peculiarities of the in- 

 fection, the determination of the efficiency of any treatment of 

 balantidiasis by clinical observation is extremely fallacious 

 unless the patient be kept under observation for a long time. 



It has, therefore, seemed possible that the probable value of 

 different drugs and chemicals in the treatment of this infection 

 could be more quickly and accurately determined by laboratory 

 tests of the balantidicidal action of them in vitro. 



The practical value of tests m vitro of the action of drugs 

 and chemicals on parasitic protozoa has been demonstrated by 

 the investigations of Vedder (1911 and 1912) and Rogers (1912a 

 and 1912b) in the application of ipecac and its alkaloid, emetine, 

 to the treatment of entamcebic dysentery. Vedder found that 

 cultures of amoebae were killed by solutions of different fluid 

 extracts of ipecac in dilutions of 1 in 10,000 to 1 in 50,000 and 

 that the active amcebicidal principle of ipecac was probably 

 emetine, since a solution of this latter substance killed the 

 amoebae in dilutions of 1 in 100,000. These tests established 

 a scientific basis for the empiric treatment of amoebic dysentery 

 with ipecac. Very recently Rogers, undoubtedly influenced by 

 Vedder's investigation, has tested in vitro the entamoebicidal 

 properties of the soluble salts of emetine. He found that Enta- 

 moeba histolytica was killed by dilutions of 1 in 100,000 of this 

 alkaloid. Applying these laboratory results to clinical medicine, 

 Rogers has reported results which are so striking in the treat- 

 ment of entamcebic dysentery and liver abscesses that, if sub- 

 stantiated, they will prove that we have a specific for this disease. 



