PART IV. CARRIAGE BY HOUSE-FLIES 135 



PAET IV. :;: 



EXPERIMENTAL WORK WITH THE HUMAN INTESTINAL PROTOZOA, 

 THEIR CARRIAGE BY HOUSE-FLIES AND THE KESISTANCE OF 

 THEIR CYSTS TO DISINFECTANT AND OTHER AGENTS. 



(1) Experimental Work. 



A number of experiments were conducted with cats, rats and 

 mice with a view to infecting them with intestinal protozoa. Most 

 of these gave negative results but are none the less interesting. 

 The following is a record of these. 



(1) E. histolytica. An attempt was made to infect two kittens 

 by means of flies which had fed on faeces containing E. histolytica 

 cysts. Batches of flies were allowed to feed on faeces and then 

 placed over bread and milk on which they deposited faeces very 

 plentifully. The kittens were then fed on the bread and milk. 

 This was repeated daily for six days, after which the kittens were 

 carefully observed. Between three and four weeks later the kittens 

 became ill and a couple of days after passed typical dysenteric 

 stools with blood and mucus. Examination of this microscopically 

 showed numerous cells of all kinds but no amoebae. The kittens 

 recovered and one was killed ten days later. There were no lesions 

 of the gut and no amoebae were found. The nature of the dysenteric 

 attack was thus undetermined. 



(2) Two cats were anaesthetized and inoculated intrahepatically 

 with about two to three cubic centimetres of liver abscess pus 

 containing numerous active E. histolytica. One cat escaped but 

 continued for some weeks to wander about the hospital grounds. 

 It remained perfectly well and active enough to avoid capture. 

 The other cat remained well for some time, but twenty-six days 

 after the inoculation it became ill and lethargic. The next day as 

 it was worse it was chloroformed. No lesions of any kind were dis- 

 covered and there was no mark of the inoculation, though there was 

 no doubt whatever that this had actually been made into the liver. 



(3) A kitten was inoculated per rectum with about ten cubic 

 centimetres of liver abscess pus containing active E. histolytica. 



* Reprinted from the Journal of the Royal Army Medical Corps, June, 1917. 



