Studies on the viability and infectivity of Fasciola hepatica metacercariae

Kim, Ji-ho; Kim, Jong-taek; Cho, Shin-hyeong; Lee, Chung-gil

Korean Journal of Veterinary Research 1998;38(1):161-166.

Ji-ho Kim¹, Jong-taek Kim², Shin-hyeong Cho², Chung-gil Lee²

¹National Animal Quarantine Service
²College of Veterinary Medicine, Chonnam National University

간질(Fasciola hepatica) 피낭유충의 생존성 및 감염성에 관한 연구

김지호¹, 김종택², 조신형², 이정길²

¹국립동물검역소
²전남대학교 수의과대학

Abstract

Fasciola hepatica eggs were obtained from the bile of infected cattle at a local abattoir. Metacercariae(MC) were produced using Lymnaea viridis, the intermediate host of the parasite. They were stored in distilled water at refrigerator($3{sim}5^{circ}C$) and at room temperature($22{sim}27^{circ}C$). The viability and infectivity of the MC were determined at monthly intervals for 12 months. The viability was determined by both microscope and excystation, and the infectivity by infecting mice. The MC stored at room temperature had a high viability up until 60 days, and thereafter the viability declined rapidly ; at day 120, only 2.5% of the MC were excysted. Most of the MC stored at refrigerator retained the viability up until 90 days, and thereafter the viability declined slowly ; about half of them were viable at day 210 and 5% of them retained the viability until day 270. The survival rates of the MC determined by microscope were always higher than those determined by excystation(p<0.05). The infectivity of the MC wisely followed the viability at the two different storage temperatures. Most of the mice infected orally with the MC died within 3-9 weeks of acute fasciolosis.

Key Words: Fasciola hepatica, Lymnaea viridis, viability, infectivity, excystation