肝吸蟲感染 淡水魚로 因한 水汚染에 關한 實驗的 觀察 = Experimental Observations on Water Contamination by Fresh-water Fish Infected with Clonorchis sinensis

다국어 초록 (Multilingual Abstract)

In this study the author observed the status of water contiamination by fresh-water fish, either alive or dead infected with Clonorchis sinensis.
The fresh-water fish used as materials were Pseudorasbora parva heavily infected with metacercariae of Clonorchis sinensis. The live fish were kept in water for a long time, and then the sediments in the water were examined to find out whether or not the liberation of the metacercariae from the body of the fish had caused contamination of the water with metacercariae.
Killed fish were also preserved in warm or cold water for some time. Moderate degree shaking was given to the preserved water once a day and half the amount of the water was replaced with tap water of the same temperature everyday.
Status of the decay of the fish, liberation of the metacercariae from the body of the fish or contamination of the preserved water by the metacercariae, and numbers of metacercariae harboured in the flesh of the fish were examined everyday. The fate of the metacercariae liberated from the fish into the water was also observed.
The results of this study can be outlined as follows;
1) No metacercariae were detected in the water which contained live fresh-water fish infected with Clonorchis sinensis.
2) The preserved water with dead or killed fresh-wate fish was found to be contaminated by the encysted and excysted metacercariae of Clonorchis sinensis, which was caused by the decay and dispersion of the flesh of the fish.
3) The encysted metacercariae survived for 2∼3days in the water at about 30℃ of 20℃, and as long as over two and half months at 70℃.
4) The excysted metacercariae survived for a few hours in the water at about 31℃, 24℃ and 7℃.
5) Most of encysted metacercariae and excysted metacercariae were found to be sinking into water of s.g. 1.000 with an average velocity of 7.6㎝ and 10.2㎝ per minute, respectively. A few encysted metacercariae were found to be floating in water.
6) The excysted metacercariae of Clonorchis sinensis, fed orally to albino rats were found fully developed to adultworms as successfully as encysted ones.