关键词: 异尖线虫Ⅲ期幼虫, 人工感染, 鼠, 病理

Abstract: ObjectiveTo observe the characteristics of biology and pathogenicity of the third stage Anisakis simplex larvae (L₃).MethodsThe survival time of the L₃ in various conditions was observed and the pathological change after experimental infection in rats was examined.ResultsThe results showed that the L₃ frozen at -20 ℃ for 10-12 h can be killed. In the temperature range of 4-10 ℃, the L₃ can survive for over 8 months. The L₃ was very active at 37 ℃， and was killed at the high temperature over 40℃ in a very short time. The ingredients for sashimi cannot kill the L₃. The experiment of rats infected by the L3 showed that about 15%-25% of the L₃ penetrated into the gastrointestinal wall or migrated into the peritoneal cavity in 2 days. After 3d the L₄ was not infectious, and died automatically in 7-10 days and could not develop into adults. The animals can be easily infected when the stomach was empty. The pathological study showed that the primary infection was a kind of reaction to foreign body, while that of the re-infection was allergic.ConclusionThe L₃ has a strong resistance to low temperature and to ingredients, it can be killed by freezing at 20℃ in 24 hours. The L₃ can not mature in the body of terrestrial mammals but causes pathological change in the stomach and allergy.

Key words: Anisakis simplex, Larva（L₃）, Experimental infection, Rat, Pathology