[Ovicidal effects of heat and disinfectants on Syphacia muris estimated by in vitro hatching].

The ovicidal effects of heat and various chemical disinfectants on an oxyurid rat nematode Syphacia muris were investigated, using the hatching methods in artificial intestinal juice. The eggs were collected from the perianal skin of spontaneously infected rats by means of a piece of transparent adhesive tapes, and these eggs were treated with each disinfectant for two hours. It was found that 70% ethanol and 80 degrees C 30 min treatments killed almost all of the eggs. However, a small number of the eggs tested was killed by 0.02% chlorhexidine digluconate or 0.05% benzethonium chloride. Alcide, 3% saponated cresol solution, 50% isopropanol, 10 ppm sodium hypochlorite and 5 ppm iodophol had some effects against the eggs, but they didn't kill the eggs completely. A biological assay through infection of the eggs to rats might be necessary because the effects of 2% formalin on the eggs were not determined by the hatching methods.