ISOSPORA HOMINIS 



coccidia, according- to Kolpakoff (1925, 1926), develop 

 in water and in physiological salt solution, and in some 

 cases in gastric juice, but no sporogony was observed 

 in pancreatic juice, bile or intestinal juice. The exit of 

 sporozoites from the oocysts of the rabbit coccidia may 

 occur in diluted intestinal juice and also when subjected 

 to gastric juice followed by intestinal enzymes (Krijgs- 

 man, 1926). That digestive juices have an influence on 

 the escape of sporozoites from the oocysts is also in- 

 dicated by the experiments of Andrews (1927) on the 

 coccidia of cats and dogs (see p. 196). 



Course of human infections. There is still some ques- 

 tion as to whether the various digestive disturbances 

 associated with human coccidial infections are due to 

 the coccidia or to some other cause. Connal (1922) has 

 given us a connected account of what appears to be an 

 infection with Isospora hominis accompanied by symp- 

 toms. His description agrees very closely with infec- 

 tions of cats with Isospora felis as described by Andrews 

 (1926b). 



The Connal infection. According to Connal, fecal ma- 

 terial containing oocysts of Isospora hominis was acci- 

 dentally thrown over the face of a laboratory worker 40 

 years of age. Some of the oocysts were probably swal- 

 lowed. After an incubation period of 6 days the patient 

 suffered from diarrhea, during which the feces appeared 

 similar to those passed after a saline purge; this con- 

 tinued for 22 days and then the feces became more copi- 

 ous and of a thick oily consistency. Seven days later 

 the stools became less fluid and during the next 2 days 

 became formed. Oocysts appeared in the feces 22 days 



193 



