230 



THE FLUKES 



V.3. 



hospital. According to Goddard there are three stages in the 

 disease caused by this parasite. There is first a period of latency 

 during which there is some asthenia and mild anemia. This is 

 followed by a period of diarrhea, in which there is more or less 



intestinal disorder; there is however? 

 no blood in the diarrheal stools. 

 There is always noticeable anemia, 

 and this may be extreme. A com- 

 bination of chronic diarrhea and an- 

 emia is said to be characteristically 

 the result of Fasciolopsis infection 

 in Shaohing. Often the abdomen is 

 protuberant in children. The third 

 stage is characterized by increased 

 anemia and a distressing amount of 

 oedema, which affects the abdominal 

 cavity first, then the legs, and finally 

 the upper portions of the body. It 

 gives the affected parts of the body a 

 very characteristic puffy and swollen 

 appearance. Goddard believes that 

 the infection is derived from eating 

 imperfectly cooked snails, some 

 species of which may act as the in- 

 termediate host. This would imply 

 nat.size, that a second intermediate host was 



FIG. 80. Fasciolopsisbuski, a ot n pppqq flr v i n fV, P Iffp hiVnrv 

 large intestinal fluke of man. x 2i. J 



Abbreviations as in Fig. 74. (Af- On the other hand it has been claimed 



ter Odhner.) , , , , . , . , . 



that the cercanse encyst in shrimps, 



but Leiper had no success in infecting hogs with the cysts which 

 he found in shrimps. 



The full life history of none of these intestinal parasites is 

 known, and we can only guess at them by analogy with more or 

 less closely related parasites about which we have more knowledge. 

 None of them do enough damage to cause more than slight in- 

 testinal irritation or catarrh, and sometimes light dysenteric 

 symptoms. They are susceptible to most of the drugs used for 

 expelling tapeworms and roundworms. Some species are said 

 not to be affected readily by santonin, though they an? ex- 

 pelled by thymol and naphthalene, and presumably by oil of 

 chenopodium. 



