PART II. WORMS PARASITIC IN MAN 

 WILLIAM W. CORT 



1. INTRODUCTION TO THE PARASITIC WORMS 



The endoparasitic helminths belong to the classes Trema- 

 toda and Cestoda under the phylum Platyhelminthes and 

 to the class Nematoda under the phylum Nemathelminthes. 

 The trematodes, commonly known as flukes, are important 

 parasites of man especially in the Far East and Africa where 

 they produce such dangerous diseases as bilharziasis, Japan- 

 ese schistosomiasis, clonorchiasis and paragonimiasis. The 

 cestodes or tapeworms are practically cosmopolitan in 

 distribution. While they are frequently encountered their 

 relation to disease is not so definite except in the case of 

 Echinococcus, which in man produces hydatids of the liver 

 and other organs. The nematodes or round worms are the 

 most prevalent and important helminths of man. In this 

 group belong the organisms which produce hookworm dis- 

 ease, filariasis and trichinosis. It is only since medicine 

 and public health work have come to be considered as 

 world problems that the diseases produced by parasitic 

 worms have come into prominence. Since such diseases 

 are very prevalent in the Tropics and Orient and there is 

 constant danger of their spread into new regions with 

 commerce and immigration, it is important that the medical 

 man, wherever located, should be acquainted with their 

 manifestations and methods of diagnosis, and should be 

 able to identify the worms which produce them and know 

 their methods of entrance into man. 



2. DIAGNOSIS OF DISEASES CAUSED BY PARASITIC WORMS 



In diseases produced by parasitic worms the clinical 

 picture is usually not very clear cut and the symptoms are 

 easily confused with those of other diseases. In infestations 



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