﻿IX, B, 1 Willets: Treatment of Entamcebiasis 97 



stools later than the fourth day from the beginning of treat- 

 ment. It is noteworthy that Deeks recognizes E. histolytica and 

 E. tetragena as distinct causes of dysentery and seems to accept 

 James' opinion that the bismuth-milk-saline treatment does not 

 cleanse the bowel of entamoebas of the species "E. tetragena." 

 As a matter of fact, it is now generally accepted that E. 

 tetragena and E. histolytica are identical. On the one hand, 

 therefore, it appears that Deeks's findings relative to the power 

 of the bismuth-milk-saline treatment to free the intestinal tract 

 of E. histolytica are rather untrustworthy, while on the other 

 hand the absence of relapses in his cases is extremely important. 



FACTORS EXERTING AN INFLUENCE UPON THE RESULTS OBTAINED 



Before proceeding to a discussion of our cases, it is deemed 

 advisable to consider five factors which exert an influence upon 

 the results obtained. 



1. Distribution of entamoeba in stools. — A fact well known by 

 persons familiar with stool examination is that entamoebae are 

 very unequally distributed in a given specimen and in different 

 specimens from an infected individual. For this reason it is 

 impossible to give more than an approximate idea of the in- 

 tensity of an infection and difficult to tell when a specimen is 

 truly negative. Hence it is necessary to adopt some arbitrary 

 standard for comparison. In this investigation a rough indica- 

 tion of the intensity of infection in the first specimen examined 

 was given by using +, + +, and + + +• In subsequent exa- 

 minations a positive report was made as soon as it was definitely 

 decided that entamoebse were present and four cover-glass prep- 

 arations were examined before a given specimen was said to be 

 negative. 



2. Number of consecutive negative examinations required to 

 ensure one of the absence of entamoebse from the intestinal 

 tract. — A glance at Tables II to V will suffice to convince anyone 

 that a single negative examination is quite insuflJicient to ensure 

 one of the absence of entamoebae from the intestinal tract. In 

 a general way, results obtained in this investigation give some 

 indication of the number of consecutive negatives to be required. 

 One negative examination was followed by a subsequent exam- 

 ination in 72 instances. The subsequent examination was 

 positive in 25, or 34.7 per cent, and negative in 47, or 65.3 per 

 cent. The examination following 2 consecutive negatives was 

 positive in 5, or 25 per cent, and negative in 15, or 75 per cent, 

 of 20 cases. The following examination in 7 cases with 3 



124293 7 



