304 



PARASITIC PROTOZOA IN RELATION TO THE WAR. 



day. The more fluid the stool the greater was the number of 

 parasites in my experience. 



Intestinal Sporozoa. 



Two genera of intestinal Coccidia have been found to occur 

 among military patients. The organisms are Isospora bigemina 

 (var. ho minis) and Eimeria stiedcs, and the former was the more 

 common. Most of the patients liecame infected with the parasites 

 in Salonika, Egypt, or Gallipoli. 



Isospora bigemina is a parasite of cats and dogs, and in these 

 animals the jejunum and ileum are most frequently infected. In 

 cases where I experimentally infected clean kittens with Isospora 

 of human origin, the jejunum and ileum showed most inflamma- 

 tion, the condition resembling that in man. Both schizogony 

 (asexual multiplication) and gametogony (production of sexual 

 forms) occur in the intestinal epithelium, and the submucosa may 

 become involved. The oocysts are oval and relatively frail in 

 appearance. They vary from 22)ix to 33/* long by i i/x, to 

 15/X broad in human fseces. Each oocyst produces two sporo- 

 blasts, each of which slowly gives rise to four sporozoites (Fig. 



Fig. 11. 



II ), a large residual mass being present in each sporocyst. Kittens 

 may act as reservoirs of Isospora. Oocysts found naturally in 

 cats may be larger and somewhat thicker walled than those in 

 man, the human parasite perhaps being a distinct species or al 

 least a new variety, for which the name ho minis is proposed. 



Eimeria stiedce, sometimes still referred to under its old name 

 of Coccidiiini oviforme, is normally a parasite of the duodenum of 

 rabbits and hares. As it also infects the livers of these animals 

 and forms oocysts there, the eating of imperfectly cooked rabbit 

 livers may be one source 'of infection. Green foodstuffs contami- 

 nated by rabbit excrement are also infective. The oocysts are 

 oval, varying in length from 24/x, to 49/* , and in breadth from 

 12^ to 28ju. Each oocyst produces four oval sporoblasts which 

 become sporocysts, and each sporocyst gives rise to two sporo- 

 zoites (Fig. 12). The oocysts and spores serve for the infection of 

 new hosts. This parasite was not often seen in the Eastern war 

 zones. 



