PART I. INCIDENCE 35 



the majority of carriers oiE. histolytica, aprotozoal organism which 

 may lead to most serious consequences. 



It seems to us that the mere fact that a man is found in the 

 course of routine examination to be infected with lamblia, 

 trichomonas or tetramitus, is no justification for certifying him as 

 a carrier who must be isolated and treated. We recognize that a 

 certain small percentage of men showing these infections are ill, 

 but quite apart from the possibility of the flagellates being the cause 

 or the only cause of the malady from which they suffer, these men 

 must be invalided on clinical grounds, and treatment may then be 

 directed against their flagellate infections if these are thought to be 

 the cause of the trouble. The test, therefore, in our opinion, of 

 every case of flagellate infection must be a clinical one, and so soon 

 as any man's symptoms clear up, even though the flagellates lamblia, 

 trichomonas and tetramitus are still present, or are known to have 

 only temporarily disappeared from the stool, the man should be 

 discharged to duty. Unless this rule is followed very soon, the 

 hospitals and convalescent camps will become filled with men who 

 are quite capable of performing their duties as good soldiers. 



It does not seem to be thoroughly realized that as there is 

 a normal bacterial flora of the human intestine so there may be a 

 normal protozoal fauna. Just as the majority of the intestinal 

 bacteria never cause any trouble whatever, so most of the intestinal 

 protozoa live in the gut without doing any harm and without 

 producing any symptoms. If this fact was properly understood 

 there would be less risk of every protozoal infection being regarded 

 as a source of danger. 



The Dysentery of the Eastern Mediterranean in 1915. 



It is now universally known that dysentery was the cause of 

 invaliding of large numbers of our soldiers from the Peninsula in 

 1915 and the impression gained ground that, at any rate during the 

 first few months of the campaign, the dysentery was mostly of the 

 amoebic type. It will be admitted that the epidemic was quite 

 unexpected, and at first arrangements for adequate diagnosis of the 

 cases did not exist, so that all the errors which will be discussed in 

 this paper must inevitably have crept in. In the majority of cases, 

 those who had to do with the diagnosis had very little or no previous 

 experience of the intestinal protozoa of man, and were unconcious 

 of the difficulties to be encountered in distinguishing between 

 pathogenic and non-pathogenic entamoebae, or even between 



