698 



Balantidium Coli 



Manson,* and a case of abscess of the lung caused by the organism byWinogradow 

 andStokvis.f 



Transmission. — The transmission of the disease can only come about through 

 the encysted form of the parasites. Great numbers are passed in the feces of the 

 infected animals, but except the encysted forms all die very quickly as the fecal 

 matter dries. Unfortunately the further life-history of the encysted forms is 

 unknown. 



CRAIGIOSIS 



Ceaigia Hominis (Calkins) t 



Craigia hominis is an ameboid and flagellated intestinal protozoan parasite of 

 man, described in 1906 by Craig§ and recently carefully and elaborately studied 

 by Barlow.ll It is a minute organism and has an amebic stage during which it 

 reproduces by simple division like a typical ameba for several generations or 

 as long as conditions are favorable. It then encysts, and within the cysts numer- 



». 



/T 





Fig. 275. — Craigia hominis (Bill 111 in \nii 1 lean Journal of Tropical Diseases). 



ous small bodies called "swarmers" develop and escape. Each of these has a 

 long single protoplasmic flagellum and is actively motile. The swarmers multiply 

 by longitudinal division for several generations after which the flagella disappear 

 and the amebic stage begins again. 



In s_6 cases of infection by this parasite studied by Barlow, diarrhea was the 

 most invariable symptom. Enterrhagia is less frequent and less severe in 

 craigiosis than in amebiasis. Of the 56 cases, 11 developed abscess of the liver, 

 one a pulmonary abscess, two appendicitis, one arthritis, two duodenal ulcer, 

 while others had more vague complications and sequela. It seems, from Barlow's 

 studies, that the parasite deserves considerable attention. The discovery of the 

 parasite was made in the Philippine Islands, but Barlow's cases were in Honduras. 

 One case has been reported in Texas, another in Tennessee. 



Barlow recognizes two species, Craigia hominis and Craigia migrans. 



HARMLESS FLAGELLATES OF THE HUMAN INTESTINES 



In certain cases of diarrhea, flagellates — Trichomonas intestinalis, Cercomonas 

 intestinalis, and Lamblia (Megastomum) intestinalis have been discovered. As, 

 however, they seem to be frequent denizens of normal intestines, it is doubtful 

 whether their presence is more than incidental. 



* "Tropical Diseases," 1900, p. 394. 



t "Niederl. Tijdschr. v. Geneeskde.," 1884, xx, No. 2, quoted by Braun. 



I Trans, xvth Internat. Congress of Hygiene and Demography, 1912, 11, 287. 

 § Amer. Jour. Med. Sciences, 1906, cxxxii,2i4. 



II The American Journal of Tropical Diseases, etc., 1915, li, 680. 



