DIFFERENTIAL DIAGNOSIS OF THE DYSENTERIES 207 



Acton and Knowles (1924) and others lay some stress on the 

 chemical reaction and the pH findings in dysenteric stools. Ander- 

 son also (1921) has called attention to the clumping of erythro- 

 cytes in the exudate of acute amoebic dysentery. Further study of 

 these things may develop points of value in diagnosis as well as 

 treatment and prognosis. Jacoby (1920) has discussed the question 

 of the reaction of bacillary exudates and as his findings differ 

 somewhat from those of Acton and Knowles, his paper should be 

 consulted. 



Two questions now arise : First, are intestinal protozoa other 

 than those I have named, capable of producing dysentery? Sec- 

 ondly, do they make their attack upon the tissues in a manner 

 different from that of Enfaiiia'ba histolytica and Balantidiinn coli 

 and is the tissue reaction diiTerent from that seen in amoebic and 

 balantidial dysentery ? 



To illustrate : Invasion of the intestinal wall of the ground mole 

 by Cyclospora karyolytica is stated by several authors to produce 

 a severe, even fatal, ''enteritis." Has the nature of this infection 

 been sufiBciently studied to justify us in citing Cyclospora as an 

 example of a protozoon that produces inflammation? What part 

 do bacteria play in the case? May not the same reservations be 

 made concerning Eiuicria cnnii, which is supposed by some ob- 

 servers to produce a similar condition in cattle.^ The case of Tri- 

 chojuoiias I shall discuss later. 



That brings us to still another question: If these animal para- 

 sites (other than E. histolytica and B. coli) do not produce dysen- 

 tery in the strict sense of the term, are they capable of initiat- 

 ing other pathological conditions that simulate dysentery to an 

 extent that involves them in differential diagnosis? Much so- 

 called evidence has been advanced in support of the view that 

 many or all of these organisms, particularly the flagellates, 

 are pathogenic. Most of this literature is of an exceedingly un- 

 scientific and unconvincing nature. Some of it I have reviewed 



(1918). 



It would appear, then, that in attacking the general problem of 

 the differential diagnosis and classification of the many and varied 

 intestinal disturbances in man, we may proceed under the follow- 

 ing assumptions which form a sufficiently established scientific 

 basis of attack : 



^ This is apart from the action of secondarily infecting bacteria. 



