130 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



infection (as judged by the cysts in the stool) was in abeyance 

 cannot be stated. The case serves to illustrate the difficulties 

 associated with the control of cases of this kind where the infec- 

 tions only reveal themselves intermittently in the stool. 



It appears, therefore, that no very satisfactory treatment for 

 lamblia infection exists. For general purposes the treatment by 

 bismuth salicylate seems to be the best and this drug can be given 

 for long periods without any harmful effects. It has the advantage 

 of clearing up the symptoms associated with lamblia infection even 

 if it does not permanently get rid of the parasite. 



It might be thought that a flagellate living in the small 

 intestine could be attacked much more readily than one in the large 

 intestine. As a matter of fact drugs seem to act more readily on 

 the lamblia infection, but as explained above the relapse almost 

 always occurs. An examination of animals infected with lamblia 

 by sectioning the gut, has shown that the flagellates live not only 

 on the surface of the intestine but that many of them make their 

 way into the glands, where they can be seen in rows on the 

 glandular epithelium. It is possible that they may spread into the 

 bile ducts, but we have no information on this subject. The 

 important point in treatment and the one which makes it so 

 difficult is that intestinal disinfectants act directly on the flagellates 

 in the gut lumen but not on those within the glands. These escape 

 destruction and eventually when treatment is stopped re-establish the 

 gut infection. This hypothesis affords an explanation of the 

 action of drugs like emetin and bismuth salicylate, which cause a 

 temporary disappearance of infection as judged by stool examinations. 



(4) Treatment of Tetramitus Infection. 



The action of emetin on this flagellate has been observed in 

 several cases of E. histolytica infection. While it can be stated 

 that emetin in the form of injections of one grain a day for twelve 

 days has no action on the flagellate, emetin administered orally has 

 a decided action. In the case of Gildel who passed tetramitus 

 regularly for three months, the administration of ^ grain of emetin 

 by the mouth for twelve days caused it to disappear. It returned, 

 however, some days after the course was completed. In practically 

 all the cases of E. histolytica infection when tetramitus was 

 present also, the latter disappeared during the course of treatment 

 by the combined method of injection and oral administration 

 (1^ grains a day). In only one case did it fail to reappear during 

 the subsequent control of the case. 



