LAMBLIA INTESTINAL1S 



59 



L. intestinalis occurs in its flagellate stage in the duodenum and 

 jejunum, and rarely as such in the other parts of the intestine. 

 Normally it is found in the large intestine as cysts, which are voided 

 with the faeces. The hosts of Lamblia include Mus musculus, M. 

 rattns, M. decnmanns, M. silvestris, Arvicola arvensis and A. amphibius 

 the dog and cat, rabbit, sheep and man. Cysts voided with the fasces 

 of infected animals reach plants or drinking water, and thence are 

 transferred to man. 



The flagellate in these different hosts exhibits some variation in 

 size and in the problematic chromatic bodies. Bensen has suggested 

 the species L. intestinalis from man, L. ninris from the mouse and 

 L. cnnicnli from the rabbit. It is not certain whether these different 

 species are necessary, as the variation may be due to differences of 

 environment. 



FIG. 20. Lamblia intestinalis. a, from the surface ; 6, from the side ; c, on intestinal 

 epithelium cells ; d, dead and e, encysted. (After Grassi and Schewiakoff.) 



Like Trichomonas, Lamblia can multiply under inflammatory 

 conditions of the alimentary tract. Thus they are found in cases 

 of diarrhoea, carcinoma of the stomach, etc. The parasites attach 

 themselves by their sucking discs to the epithelial cells of the gut 

 (fig. 20, c), and though their numbers may be very great, their direct 

 pathological significance is not fully known. Their occurrence in 

 cases of diarrhoea has been explained as being due to the increased 

 peristalsis, which has detached the parasites from the epithelium. 

 Free flagellate forms perish in stools if kept, more especially if the 

 temperature falls below o C. or rises above 40 C. Lamblia has 

 often been found in dysenteric diseases, especially in the East, and 

 is said to be the causal agent of certain diarrhoeas in India. Math is 

 {1914) 1 found Lamblia in cases of diarrhoea with dysenteriform stools 

 in Tonkin. He also discovered healthy carriers of Lamblia cysts. 



1 Bull. Soc. Med. Chirurg. Indo-Chine, v, p. 55. 



