[Preliminary observation of infectivity of isolated alveolar hydatid after cryopreservation].

Alveolar hydatids of Echinococcus multilocularis obtained from the peritoneal cavity of mice were subject to freezing at -10 degrees C and -30 degrees C respectively. After 130-200 days' storage, the alveolar hydatids were transferred into the mouse peritoneal cavity for viability and infectivity testing. It was found that the alveolar hydatids stored at -10 degrees C were more severely damaged than those stored at -30 degrees C. The viability of the isolated alveococcus lasted half a year at -30 degrees C.