OF THE ALniENTARY TRACT 49 



returning soldiers after the last war did not seem 

 justifiable and has apparently not proven warranted. 

 Since the cyst is the only infective stage of the 

 parasite, prevention of spread of it depends upon 

 preventing this body from reaching the mouth of 

 man. The control of flies and the protection of ex- 

 creta and food from them is important. In regions 

 where human excreta are used as fertilizer uncooked 

 vegetables are dangerous. Public food handlers of all 

 sorts may act as carriers and well regulated protection 

 should involve examination of them for this organ- 

 ism. It is the apparently healthy carrier, not the 

 person with amoebic dysentery, who is the dangerous 

 factor in transmitting Endamoeba histolytica. Pro- 

 tection against this amoeba involves such sanitary 

 practices as are used against typhoid infection, in- 

 cluding consideration of the carrier. Walker (1911) 

 names those who have recovered from amebic dysen- 

 tery but still harbor the organism ^'convalescent car- 

 riers" and the person who has the parasite without 

 having suffered from the acute disease the '^contact 



carrier." 



As previously referred to, the writer (1915) dis- 

 covered a focus of natural infection of wild rats with 

 an amoeba indistinguishable from Endamoeba histo- 

 lytica in a house occupied by negroes, where a cellar 

 was used as a ''privy." From this habitation at least 

 two cases of amoebic dysentery were traced. Brug 

 (1918) found natural infection of two wild rats in 

 Java. Chiang (1925) also discovered in laboratory 



