HUMAN LIVER FLUKES 227 



of the oriental species. Their occurrence in man in countries 

 where fresh-water fish is a common article of diet, and their 

 frequency in animals which eat raw fish, strongly suggest fishes 

 as intermediate hosts. 



These liver flukes, like the sheep fluke, live chiefly in the gall 

 bladder and bile ducts where they often cause much mechanical 

 obstruction on account of their large numbers. Severe infec- 

 tions such as occur in countries like Japan where raw fish is 

 commonly eaten cause symptoms of a very serious nature. One 

 of the most prominent of these is enlargement of the liver ac- 

 companied by more or less bloody diarrhea; the latter becomes 

 more and more constant as time goes on. The liver sometimes 

 becomes painful, and jaundice is a frequent symptom. The 

 patient becomes anemic, emaciated and weak, and is ready prey 

 for other diseases. There are often periods of partial recovery 

 followed by relapses, probably due to reinfections, and the patient 

 ultimately becomes exhausted and succumbs to a cold, an attack 

 of malaria, or other ailment from which one would ordinarily 

 recover readily. 



There is no specific treatment for the disease. The only 

 measures that can be taken are to remove the patient from any 

 possible source of reinfection and to keep him in the best possible 

 general health, with wholesome diet, good air and proper ex- 

 ercise. How long the flukes persist in the liver is not known. 



Means of prevention of the disease are suggested by what is 

 known of the life history of the parasites. The most important 

 measure is unquestionably the suppression of the habit of eating 

 uncooked fish in places where the disease is endemic. 



Kobayashi has shown that while the larvae of C. sinensis are 

 killed at once on exposure to a boiling temperature and in a short 

 time when exposed to considerably lower temperatures, they are 

 not destroyed by exposure to vinegar for five hours, nor by re- 

 frigeration. 



A second measure, which is far less reliable, is the prevention 

 of contamination of water in which fish live. It is impossible to 

 prevent some contamination of water by the lower animals which 

 carry the infection, and it is nearly as difficult to prevent con- 

 tamination by human faeces. The almost universal use of night 

 soil (human faeces) for fertilizer in oriental countries is a serious 

 hindrance to the sanitary disposal of such infected material. 



