v . 



PART I. INCIDENCE 27 



In the case of the London convalescents who were examined in 

 London by one of us (C. M. W.) during the latter part of 1915, the 

 small amoeba now entered as E. nana was in the original report 

 entered as Amoeba Umax. As will be explained below this diagnosis 

 was most probably erroneous. Coccidium (isospora) was found 

 once, and the flagellates Tricercomonas intestinalis and Waskia 

 intestinalis several times in Alexandria, but as they were not found 

 at the first examination of the cases, they are not included in the 

 table. 



General Remarks on the Protozoal Infections. 



The results of the examinations of the various groups described 

 above are set out in tabular form in Table IX. 



(1) Entamceba coli. It will be seen at once that E. coli is by 

 far the commonest protozoon of the human intestine in Egypt 

 as in all other countries where it has been sought. Amongst the 

 British troops it was found most commonly in the case of the 

 convalescents, 31'7 per cent, of those examined showing this 

 parasite. The convalescents from the Eastern Mediterranean 

 examined in London during the latter half of the year 1915 

 showed a similar high percentage of E. coli infections. It is 

 difficult to explain why the convalescents (mostly from dysentery 

 or other intestinal disorders) should show a higher percentage than 

 healthy men of a non-pathogenic amoeba like E. coli. It is possible 

 that a damaged intestine is more liable to become infected with 

 this protozoon, though why this should be so it is difficult to 

 imagine. 



The high percentage of E. coli infections amongst the natives 

 of Alexandria has already been referred to above. It is interesting 

 to note that the forty-eight British West Indians examined show a 

 lower percentage of infections than any other group of healthy men 

 examined. The low figure in the hospital cases and the men in 

 Gabarri Prison, who were mostly suffering from some intestinal 

 disorder, is to be explained by the soft or liquid character of the 

 stool, as has been noted above. If a series of diarrhoeic cases are 

 examined it can be stated, as a rule, that the figures for the amoebae 

 will be below the average for healthy men, while those for tbe 

 flagellates will be above. 



(2) Entamceba nana. The small amoeba which we have called 

 E. nana was found to be a common parasite in Egypt. It was 

 some time before we were able to identify the cyst of this amoeba, 

 for in the first two or three months we were accustomed to regard 



