46 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



which contained red blood corpuscles, were present. The case was 

 treated accordingly and the diagnosis was later confirmed bacterio- 

 logically by the isolation of a bacillus of the Flexner type. Five 

 days later the patient was passing brown unformed motions free 

 from mucus and some cysts of E. coli were found. Free amoebae 

 had been present every day before this. The following day there 

 were present both cysts of E. coli and cysts of E. histolytica, and 

 as the patient improved in health these became more numerous, 

 while a large trichomonas infection also appeared. It seems quite 

 clear that this was a case of bacillary dysentery in a man who was 

 a carrier of E. histolytica, E. coli and trichomonas. The fact that 

 the amoebic infection, which was evidently playing no part in the 

 acute symptoms, was left untreated, did not affect the recovery of 

 the patient from his attack of bacillary dysentery. The E. histolytica 

 infection was treated later. 



As a result of observations on a long series of cases we would 

 lay down the following rules as a guide to the diagnosis of amoebae 

 in the stool : 



(a) If amoebae containing red blood corpuscles are present in a 

 stool, whether evidently dysenteric or not, they are E. histolytica, 

 and mean that some active dysenteric process is going on. 



(b) If the actual amoebic dysenteric process is so acute as to 

 demand emetin treatment, then amoebae with included red cells 

 will almost certainly be present in the stool. 



(c) If amoebae, none of which contain red blood corpuscles, 

 are present in a dysenteric stool, then the case is either (a) bacillary 

 dysentery (or other form of dysentery) with an infection of E. coli, 

 or (b) bacillary dysentery (or other form of dysentery) occurring 

 in 'a carrier case of E. histolytica in which there is no active 

 amoebic dysenteric process in progress. 



(d) In either case mentioned under (c) no anti-amoebic treatment 

 is urgent, so that the case can be watched for a few days, during 

 which encysted forms of either E. coli or E. histolytica will 

 almost certainly appear as the acute symptoms subside, and the 

 diagnosis will be established. 



(e) Amoebae, none of which contain red blood corpuscles, and 

 which occur in non-dysenteric stools, may be either E. coli or 

 E. histolytica. In such cases cysts arfe nearly always associated 

 with the amoebae, but if not, treatment for the amoebic infection 

 being never urgent, or not required at all, a diagnosis can 

 be made by examining for a few days till cysts appear, as they 

 invariably do. 



