54 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



amoabae in the stool. Another case, Spiers, gave a similar history 

 of a slightly shorter duration. Another case of this kind was seen 

 by one of us (C. M. W.) in London some years ago, and was one of 

 a postman who had been invalided from the West Indies on account 

 of dysentery. He stated he had had repeated attacks during a 

 period of five years since his return to England. Examination of 

 the stool showed that it was soft and unformed and was dotted 

 over with small flakes and streaks of mucus as is common in these 

 cases. There was a very large infection of cysts of E. histolytica 

 and small amosbae. 



These cases show clearly that individuals may remain as 

 unhealthy carriers over long periods and as far as we can judge it 

 may be for the rest of life. 



The length of time that a person may remain a healthy carrier 

 is much more difficult to decide, for there is no history of repeated 

 dysentery to guide us. One case of known infection has been under 

 observation for six months, and though cysts of E. histolytica have 

 been present constantly there has been no dysentery during this 

 period, nor was there a previous history of dysentery or diarrhoea. 

 This case (Cox) was given a course of emetin injections, which only 

 caused the cysts to disappear from his stool for a short time.* 



That infections of this kind can exist for long periods without 

 any symptoms is borne out by the fact that such a large percentage 

 of the "carriers" we have found during the routine examination 

 of healthy men have given no history of dysentery whatever. For 

 instance, of 106 carriers discovered amongst 1,979 healthy men 

 only 16 gave any history of dysentery, and it is certain that the 

 latter figure is too high, for in no case can we be certain of the type 

 of dysentery from which the case suffered. 



In a certain number of instances men who have been found to 

 be carriers have been brought into hospital for treatment, and while 

 under control before treatment was commenced it was noticed that 

 the infection began to decline and finally disappeared. Three such 

 cases were examined regularly for fifteen, eighteen and twenty-six 

 days respectively after the spontaneous disappearance of the 

 E. histolytica cysts from the stool without there being any 

 recurrence. It was impossible to retain these men any longer, 

 but whether the observation indicates a spontaneous recovery or 



After the lapse of a further twelve months Mr. E. E. Savage has kindly 

 re-examined the case. There has been no dysentery while E. histolytica is still 

 present. This case has, therefore, remained neglected for at least one and a half 

 years without symptoms attributable to the infection. 



