CHAPTER XV 

 OTHER INTESTINAL ROUNDWORMS 



General Account. — As compared with the hookworms all the 

 other intestinal roundworms, except trichina, which will be dis- 

 cussed in the following chapter, sink into relative insignificance, 

 but there are several species which are very common in some parts 

 of the world and some which are of very wide distribution. The 

 pathological effects of some of these worms appear to be slight 

 or almost entirely neghgible, — : while others, at least in individual 

 cases, cause severe symptoms and may even be a direct cause 

 of death. Recently, as has been remarked in a preceding chap- 

 ter, ftiore and more suspicion is being aroused against various 

 intestinal worms, especially those which habitually inhabit the 

 ccecum and appendix, as playing a leading part in producing 

 appendicitis. The relation of intestinal worms to bacterial in- 

 fections is discussed on pp. 203-204. 



As regards the selection of a drug for treatment of any of 

 these rarer intestinal parasites, certain general principles should 

 be of value. As has been pointed out by Hall and Foster, 

 " almost all anthelmintics {i.e., drugs used against worms) are 

 poisons, intended to kill or stupefy or otherwise disable and re- 

 move worms, while at the same time inflicting a minimum amount 

 of damage on the host animal by virtue of the comparative 

 insolubility of the drugs or their rapid elimination." For worms 

 situated in the upper portions of the digestive tract, drugs such 

 as chloroform, which are rapidly absorbed and eliminated, can 

 be used, whereas for worms situated in the lower portions of 

 the digestive tract, insoluble drugs would in general be better. 

 That certain drugs have more or less specific action against 

 certain species of worms is true, as evidenced by the case of oil 

 of chenopodium against ascarids, and chloroform against hook- 

 worm. It is quite probable, however, that this apparently spe- 

 cific action may be due rather to a mode of life of the worm 

 affected which makes it particularly easily reached by the drug. 

 Hall and Foster, for instance, suggest that the striking efficiency 



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