Studies on the viability and infectivity of Fasciola hepatica metacercariae

간질(Fasciola hepatica) 피낭유충의 생존성 및 감염성에 관한 연구

  • Kim, Ji-ho (National Animal Quarantine Service) ;
  • Kim, Jong-taek (College of Veterinary Medicine, Chonnam National University) ;
  • Cho, Shin-hyeong (College of Veterinary Medicine, Chonnam National University) ;
  • Lee, Chung-gil (College of Veterinary Medicine, Chonnam National University)
  • Received : 1998.02.17
  • Published : 1998.03.25

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.