26 PROTOZOAN PARASITISM 



of man, and the prevention of it involves breaking 

 the chain of sequence at some convenient or avail- 

 able point. 



Thorough application of commonly recognized hy- 

 gienic and sanitary procedures, personal and public, 

 would probably suffice to control most if not all of 

 these human infestations. Such a thorough applica- 

 tion as to bring about their eradication is not to be 

 anticipated, however, at the present or in the immedi- 

 ate future, particularly as regards personal hygiene 

 and the control of the hand to mouth transmission, 

 which is believed to be probably the most important 

 means of spread of these parasites in modern com- 

 munity life. 



It should be emphasized that the carrier furnishes 

 the real problem in this division of preventive medi- 

 cine. He it is who furnishes the transferable stage 

 of the organism, not the person acutely ill of an in- 

 fection which is being excreted in a non- transmissible 

 stage of the organism. A patient with acute am- 

 oebic dysentery is of no danger to anyone else, the 

 amoebae he passes are harmless. It is in the absence 

 of diarrhoea that he becomes of danger to his fellow. 



When it is called to mind that apparently about 

 10% of the population of any country harbors a 

 pathogenic amoeba in transferable form and that 

 probably from 30% to 50% of all people carry 

 some intestinal protozoon, to say nothing of the or- 

 ganisms of the mouth, it is to realize how hopeless 

 it is to contemplate any considerable reduction of 



