50 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



(3) Are the four Nuclear Cysts of histolytica type necessarily 



an Indication of Infection with the Pathogenic Amoeba f 

 All the cases of E. histolytica infections have been diagnosed 

 either by the cysts or the presence of amoebae with included red 

 blood corpuscles ; no amoebae even in dysenteric stools which were 

 not associated with cysts of E. histolytica, or with amoebae showing 

 definite included red blood corpuscles, were entered as E. histolytica. 

 The percentage of carrier cases amongst the supposed healthy men, 

 as we have already pointed out, is fairly high and would be actually 

 still higher if allowance were made for the error entering into the 

 single examination system. This being the case, one naturally 

 wonders why, with so many carriers about, is actual amoebic 

 dysentery such an uncommon disease in Egypt at the present 

 time ; and secondly, are the tests one applies for the detec- 

 tion of carriers reliable, and are the cysts of E. histolytica as 

 one recognizes them in reality the cysts of the pathogenic amoeba 

 which produces amoebic dysentery ? Doubts on this score have 

 arisen in the minds of some, naturally enough when one realizes 

 the great discrepancy between the number of carriers and acute 

 cases. That the so-called cysts of E. histolytica are what they are 

 supposed to be can hardly be doubted by anyone who has followed 

 the literature dealing with the subject during the last few years. 

 Cases of amoebic dysentery have been followed by several observers 

 through convalescence and as the dysenteric symptoms abate the 

 characteristic cysts begin to appear in the stools. Other cases 

 which have been in the " carrier " condition passing cysts in the 

 stools have relapsed into attacks of acute amoebic dysentery. 

 Cysts from carrier cases have been administered to cats and these 

 have contracted acute amoebic dysentery and even amoebic abscess 

 of the liver. Further, Darling has shown that cats infected in this 

 way if they tend to recover from the attack of amoebic dysenter}^ 

 commence passing E. histolytica cysts in the stool. The evidence 

 seems to be as complete as it possibly can be, short of some method 

 of maintaining E. histolytica in pure artificial culture. Some 

 further evidence in this direction has been the outcome of our 

 observations on cases of amoebic dysentery and carriers in Egypt. 

 Two cases Blair and Kussell, H. were admitted to hospital with 

 amoebic dysentery, there being blood and mucus stools containing 

 active amoebae with included red blood corpuscles but no cysts. 

 The cases were treated with emetin and the dysenteric symptoms 

 and the amoebae disappeared. Both these cases relapsed later. 

 Case Kussell, H., began to show cysts of E. histolytica with small 



