144 PROTOZOAN PARASITISM 



TRICHOMONAS HOMINIS 



The trichomonad of the human intestine, Tri- 

 chomo7ias hominis, is apparently variable in its prev- 

 alence in different localities, at least so in the experi- 

 ence and reports of reliable students of it. 



Craig (1926), from an analysis of several studies 

 by Kofoid, Kornhauser and Plate in the United 

 States, Mathews and Smith and Jepps in England, 

 Faust in China, and from his own observations, is of 

 the opinion that this organism is the least common of 

 the better known intestinal flagellates. He believes 

 that it is present in only from 0.5% to 1% of the in- 

 habitants of temperate regions. 



Compiling the results of a number of reports pub- 

 lished by English, American and French investiga- 

 tors from 1916 to 1919, Hegner and Payne (1921) ar- 

 rive at an average incidence, in 20,000 reported cases, 

 of 3% for Trichomonas hominis. 



Boeck and Stiles (1923) give an incidence, in 8029 

 persons examined by them, of 0.007%. However, 

 the conditions of their examinations did not favor 

 trophozoites and probably this organism was largely 

 missed. 



Jepps (1923), examining 674 Tamils and 350 Chi- 

 nese in the same hospital, found Trichomonas hom- 

 inis in 16.5% of the former and in 2.2% of the latter. 



Barrow (1924) found less than 2% in 725 of his 

 patients harboring some type of intestinal proto- 

 zoon. He found an incidence of 8.3% in 79 cases of 

 arthritis deformans. 



