The effect of physical agents on hydatid scolex viability

Abstract

By employing a combination of sub-stage heating and supra-vital staining with eosin or neutral red it was found that viable and non-viable hydatid scolices could be distinguished microscopically. Using this technique a study of the effect of heat in vitro on hydatid scolices has shown that death resulted from exposures at 50° C. for 70 min. and at 55° C. for 30 min.Experiments on the effect of boiling in destroying the contents of fertile cysts embedded in sheep liver showed that when offal was added directly to boiling water destruction of scolices was complete after 40 min. boiling. When the infected liver was placed in cold water brought to the boil, scolex death was assured only after 30 min. subsequent boiling.Ultra-violet radiations of 2537 A. did not kill scolices under the conditions adopted. Although this wave-length would apparently be ineffective as a scolicicidal agent in surgery of the human hydatid cyst, irradiation of hydatid fluid containing scolices might offer a simple method for initial sterilization of scolex culture media.The author wishes to acknowledge many helpful suggestions and loan of the Hanovia lamp by Dr G. M. Richardson of the Virus and Immunology Research Department, Otago Medical School.