PART I. INCIDENCE 39 



ground that many of the cases were suffering or had just suffered 

 from diarrhoea, a condition which tends to get rid of amoebic 

 infections (temporarily) but tends to reveal a flagellate infection 

 which is not easily detected in the formed stool. 



(8) An examination of 524 healthy natives in Hadra Prison, 

 Alexandria, showed a high percentage of infection with E. 

 histolytica (13'5), E. coli (48-6) and I-cysts (14'8). The flagellate 

 infections were low. In only three of the 524 cases could the 

 stool be described as abnormal. Similar results were obtained 

 in the examination of human faecal deposits collected in and around 

 Alexandria. 



(9) It is evident that the native of Egypt is acting as a reservoir 

 of infection for the intestinal protozoa with which the British 

 troops have become and are becoming infected. 



(10) Lamblia and trichomonas have been found to occur in 

 Alexandria cats. These animals, with rats and mice, may act as 

 reservoirs of infection. 



(11) The introduction of carriers of E. histolytica into England 

 at the present time as a result of the movements of troops is 

 unlikely even under existing conditions to be followed by severe 

 outbreaks of amoebic dysentery. In the past carriers have been 

 constantly returning to England without any severe outbreaks 

 resulting. 



(12) It is impracticable to examine large bodies of healthy 

 troops with a view to eliminating the carriers of E. histolytica. 

 The majority of the carriers are perfectly healthy and we know 

 nothing of the percentage of these carriers which actually pass on 

 to a condition of amoebic dysentery. Nor do we know to what 

 extent a carrier is likely to hand on his infection to another. It is 

 clear that there are many healthy carriers of E. histolytica for 

 every one who actually gets amoebic dysentery. 



(13) In the case of men invalided for intestinal disorders and 

 are still ill, if E. histolytica is found to be present, the condition 

 can be treated, and if clinical recovery takes place this can be 

 followed by discharge to duty. When every able-bodied man is 

 needed for service in time of war it is not reasonable to detain any 

 one just because he happens to be a carrier of E. histolytica. The 

 number of undetected carriers amongst the healthy troops is far 

 greater at the present time than amongst those invalided for one 

 cause or another. It is unnecessary to examine all recovered 



