Balantidium Diarrhea 655 



abscess of the liver may be caused by balantidia, and has been reported by 

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

 gradow and Stokvis.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. 



CRAIGIA HOMINIS (Calkins^ 



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. || 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 

 numerous small bodies called "swarmers" develop and escape. Each of these 

 has a long single protoplasmic flagellum and is actively motile. The swarmers 



Fig. 268. Craigia hominis (Barlow, in American Journal of Tropical Diseases). 



multiply by longitudinal division for several generations after which the flagella 

 disappear and the amebic stage begins again. 



In 56 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, n developed abscess of the liver, 

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

 while others had more vague complications and sequelae. 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 Hon- 

 duras. 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. 



j Trans, xvth Internal. Congress of Hygiene and Demography, 1912, n, 287. 



Amer. Jour. Med. Sciences, 1906, cxxxn, 214. 



|| The American Journal of Tropical Diseases, etc., 1915, n, 680. 



